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Images of Large Magellanic Cloud and Goddard Space Flight Center (GSFC)
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Hubble's Improved Optics Rev
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| Title |
Hubble's Improved Optics Reveal Incredible Detail in Giant Cloud of Gas and Dust |
| General Information |
What is an Early Release Observation? A photograph of a celestial object that demonstrates the performance of a new Hubble camera. What is an American Astronomical Society Meeting release? A major news announcement issued at an American Astronomical Society meeting, the premier astronomy conference. An image of a star-forming region in the 30 Doradus nebula, surrounding the dense star cluster R136. The image was obtained using the second generation Wide Filed and Planetary Camera (WFPC-2), installed in the Hubble Space Telescope during the STS-61 Servicing Mission. The WFPC-2 contains modified optics to correct for the aberration of the Hubble's primary mirror. The new optics will allow the telescope to tackle many of the most important scientific programs for which the it was built, but had to be temporarily shelved with the discovery of the spherical aberration in 1990. |
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Supernova Blast Begins Takin
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| Title |
Supernova Blast Begins Taking Shape |
| General Information |
What is an American Astronomical Society Meeting release? A major news announcement issued at an American Astronomical Society meeting, the premier astronomy conference. Though the brightest supernova in four centuries lit up the southern sky almost exactly 10 years ago on Feb. 23, 1987, astronomers have waited a decade for the ballooning fireball to become large enough ? about one-sixth of a light-year ? to be resolved from Earth's orbit with the Hubble telescope. Hubble's sharp "eyes" have resolved a dumbbell-shaped structure ? one-tenth of a light-year long ? that consists of two blobs of debris expanding apart at nearly 6 million mph from each other. This Hubble picture shows the supernova, designated 1987A, and its neighborhood. The four frames follow the evolution of the supernova debris. Read more: * Release Text [ http://hubblesite.org/newscenter/archive/releases/1997/03/text/ ] |
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Hubble Chemically Analyzes t
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| Title |
Hubble Chemically Analyzes the Ring around Supernova 1987A |
| General Information |
What is an Early Release Observation? A photograph of a celestial object that demonstrates the performance of a new Hubble camera. These pictures from the Hubble telescope's imaging spectrograph provide a new and unprecedented look at one of the most unique and complex structures in the universe ? a light-year-wide ring of glowing gas around supernova 1987A, the nearest stellar explosion in 400 years The long-slit spectrograph viewed the entire ring system, dissecting its light and producing a detailed image of the ring in each of its component colors [the colorful loops on the right]. Each color represents light from specific elements in the ring's gases, including oxygen [single green ring], nitrogen and hydrogen [triple-orange rings], and sulfur [double-red rings]. By dismantling the ring into its different puzzle pieces ? its component elements ? astronomers hope to put together a picture of how the ring was created. The picture on the left is a view of the entire supernova. |
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Hubble Reveals Invisible Hig
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| Title |
Hubble Reveals Invisible High-Speed Collision around Supernova 1987A |
| General Information |
What is an American Astronomical Society Meeting release? A major news announcement issued at an American Astronomical Society meeting, the premier astronomy conference. The highest velocity material expelled in a cataclysmic, stellar explosion 10 years ago has been detected for the first time by the Hubble telescope's imaging spectrograph. The top image, taken with Hubble's visible-light camera, shows the orange-red rings surrounding Supernova 1987A in the Large Magellanic Cloud. The glowing debris of the supernova explosion, which occurred in February 1987, is at the center of the inner ring. The small, white square indicates the location of the imaging spectrograph aperture. The Hubble data in the middle panel [and a schematic representation in the bottom panel] shows the presence of glowing hydrogen expanding at a speed of 33 million mph (15,000 kilometers per second) coming from an extended area inside the inner ring. |
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Hubble Telescope Reveals Swa
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| Title |
Hubble Telescope Reveals Swarm of Glittering Stars in Nearby Galaxy |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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NASA Space Observatories Gli
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| Title |
NASA Space Observatories Glimpse Faint Afterglow of Nearby Stellar Explosion |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Back to top [ #top ] |
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New Shocks For Supernova 198
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| Title |
New Shocks For Supernova 1987A |
| Explanation |
In February of 1987, astronomers witnessed the brightest supernova [ http://imagine.gsfc.nasa.gov/docs/science/know_l1/supernovae.html ] of modern times - supernova 1987A [ http://heritage.stsci.edu/public/feb4/sn1987anino.html ] in the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap951027.html ]. Mysterious rings [ http://antwrp.gsfc.nasa.gov/apod/ap000206.html ] of material surrounding the expanding stellar debris [ http://oposite.stsci.edu/pubinfo/pr/97/03.html ] were soon emitting a visible glow excited by intense light from the explosion. After fading over the intervening years, the interior ring has just been seen to sprout [ http://oposite.stsci.edu/pubinfo/pr/2000/11/ animation.html ] four new hotspots, as illustrated in these two versions of a Hubble Space Telescope image [ http://oposite.stsci.edu/pubinfo/pr/2000/11/pr.html ] recorded on February 2nd. The abrupt appearance of the new features suggests that matter from the stellar blast wave itself has begun to slam into the ring in earnest, shock-heating the gas and producing the bright hotspots. The left-hand picture shows the glowing ring, initially excited by light from the explosion, along with the shocked hotspots. The right-hand picture has been further computer enhanced to emphasize the hotspots. The brightest spot at the right was first observed [ http://antwrp.gsfc.nasa.gov/apod/ap980217.html ] in 1997, while the four spots on the left half of the ring are new. Astronomers now eagerly anticipate a dramatic rejuvenation [ http://www.kidsnspace.org/ ] of the glowing ring as the bulk of the blast wave material, traveling at about 60 million kilometers per hour, continues to plow into it. |
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XMM-Newton First Light: X-Ra
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| Title |
XMM-Newton First Light: X-Rays From The LMC |
| Explanation |
Recently [ http://sci.esa.int/missions/newsitem.cfm?TypeID=20&ContentID=9291 ] the European Space Agency released this and other spectacular "first light" pictures [ http://heasarc.gsfc.nasa.gov/docs/xmm/xmmhp_gal_sci.html ] from its new orbiting x-ray observatory [ http://antwrp.gsfc.nasa.gov/apod/ap991221.html ], christened XMM-Newton [ http://sci.esa.int/xmm/newton.html ]. A churning region of star birth and death in our small neighboring galaxy, the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap980124.html ] (LMC), this field was one of several chosen to test out XMM-Newton's x-ray imaging [ http://imagine.gsfc.nasa.gov/docs/science/know_l2/ xtelescopes_physics.html ] capabilities. The picture is a false-colour one in which low energy x-rays are translated to red, medium energy to green, and high energy to blue. Image colours [ http://antwrp.gsfc.nasa.gov/apod/ap000203.html ] therefore represent the relative million degree temperatures of the x-ray emitting regions, red being the coolest and blue the hottest. Remains of the star that exploded as Supernova 1987a [ http://antwrp.gsfc.nasa.gov/apod/ap951027.html ] appear here as the white x-ray source at the lower right, while another supernova remnant [ http://imagine.gsfc.nasa.gov/docs/teachers/lessons/supernova/ supernova_cover.html ], cataloged as N157D is the brightest source at the upper left. The bluish arc (near center) also appears to be a supernova remnant [ http://antwrp.gsfc.nasa.gov/apod/ap990307.html ] whose expanding debris cloud [ http://chandra.harvard.edu/xray_sources/supernovas3.html ] is interacting with the LMC's local interstellar gas. |
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Four Supernova Remnants
| Title |
Four Supernova Remnants |
| Explanation |
These four panels [ http://chandra.harvard.edu/photo/2006/4snr/ ] show x-ray images of expanding cosmic debris clouds, tens of light-years across, in nearby galaxy the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap060510.html ]. The supernova remnants (SNRs) are the results of two types of stellar explosions [ http://chandra.harvard.edu/xray_sources/supernovas.html ] and are arranged in order of apparent age or the time since light from the initial explosion first reached planet Earth. Clockwise starting at the upper left are remnants aged 600 years, 1,500 years, 10,000 years and 13,000 years. The first three result from a Type Ia [ http://en.wikipedia.org/wiki/Supernova#Type_Ia ] explosion - the destruction of a white dwarf star [ http://antwrp.gsfc.nasa.gov/apod/ap060521.html ] by a thermonuclear blast triggered by mass accreted from a stellar companion. The fourth (lower left) is a Type II [ http://en.wikipedia.org/wiki/Supernova#Type_II ] explosion - triggered by the final collapse of the core of a massive star [ http://antwrp.gsfc.nasa.gov/apod/ap060602.html ]. A neutron star, the remnant of the collapsed core, lies at its center [ http://antwrp.gsfc.nasa.gov/apod/ap050326.html ]. |
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A Cerro Tololo Sky
| Title |
A Cerro Tololo Sky |
| Explanation |
High atop a Chilean [ http://www.cia.gov/cia/publications/factbook/geos/ ci.html ] mountain lies one of the premier observatories of the southern sky: the Cerro Tololo Inter-American Observatory [ http://www.ctio.noao.edu/ ] (CTIO). Pictured above [ http://www.noao.edu/image_gallery/html/im0081.html ] is the dome surrounding one of the site's [ http://www.ctio.noao.edu/new/Sky%20Conditions/Webcam/ ] best known instruments, the 4-meter Blanco Telescope [ http://www.ctio.noao.edu/telescopes/4m/base4m.html ]. Far behind the dome are thousands of individual stars and diffuse light from three galaxies: the Small Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap050617.html ] (upper left), the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap060510.html ] (lower left), and our Milky Way Galaxy [ http://www.anzwers.org/free/universe/ milkyway.html ] (right). Also visible just to Blanco's right is the famous superposition [ http://antwrp.gsfc.nasa.gov/apod/ap050129.html ] of four bright stars known as the Southern Cross [ http://science.nasa.gov/ppod/y2003/31mar_carina.htm ]. A single 20 second exposure, this digital image was recorded with a sensitive detector intended for astronomical imaging. |
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The Large Magellanic Cloud i
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| Title |
The Large Magellanic Cloud in Infrared |
| Explanation |
Where does dust collect in galaxies? To help find out, a team of researchers [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2005AAS...207.6345M ] took the most detailed image ever of gas clouds and dust [ http://antwrp.gsfc.nasa.gov/apod/ap030706.html ] in the neighboring Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap060510.html ] (LMC) galaxy. The composite image, shown above [ http://www.spitzer.caltech.edu/Media/releases/ssc2006-17/ssc2006-17b.shtml ], was taken by the Spitzer Space Telescope [ http://www.spitzer.caltech.edu/about/index.shtml ] in infrared light [ http://imagers.gsfc.nasa.gov/ems/infrared.html ], which highlights the natural glow of the warm materials returned to the interstellar medium [ http://antwrp.gsfc.nasa.gov/apod/ap020210.html ] by stars. The above mosaic [ http://www.spitzer.caltech.edu/Media/releases/ssc2006-17/ssc2006-17b.shtml ] combines 300,000 individual pointings to create a composite 1,000-times sharper than any previous LMC image. Visible are vast [ http://antwrp.gsfc.nasa.gov/apod/ap050306.html ] clouds of gas and dust [ http://en.wikipedia.org/wiki/Interstellar_dust ], showing in graphic detail that dust prefers regions near young stars (red-tinted bright clouds), scattered unevenly between the stars (green-tinted clouds), and in shells around old stars (small red dots). Also visible are huge cavern [ http://antwrp.gsfc.nasa.gov/apod/ap060226.html ]s cleared away by the energetic outflows of massive former stars. The faint blue (false-color) glow across the bottom is the combined light from the old stars in the central bar [ http://www-int.stsci.edu/~marel/lmc.html ] of the LMC. The LMC [ http://en.wikipedia.org/wiki/Large_Magellanic_Cloud ] is a satellite galaxy [ http://www.astro.uu.se/~ns/mwsat.html ] to our own Milky Way Galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap000518.html ], spans about 70,000 light years [ http://chandra.harvard.edu/photo/cosmic_distance.html ], and lies about 160,000 light years away toward the southern constellation of the Swordfish [ http://en.wikipedia.org/wiki/Swordfish ] (Dorado [ http://www.astronomical.org/portal/modules/wfsection/article.php?articleid=33 ]). |
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NGC1850: Star Cluster in the
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NGC1850: Star Cluster in the LMC |
| Explanation |
NGC1850 is a large cluster of stars located a mere 166,000 light-years from Earth in our neighboring galaxy the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap000222.html ] (LMC). The colors [ http://aibn47.astro.uni-bonn.de/~gallery/articles/ color.html ] in this beautiful Hubble Space Telescope composite image [ http://oposite.stsci.edu/pubinfo/PR/94/40.html ] of the cluster reveal [ http://antwrp.gsfc.nasa.gov/apod/ap990312.html ] different populations of stars. Yellowish stars are the main cluster stars, sun-like main sequence hydrogen burners [ http://antwrp.gsfc.nasa.gov/htmltest/gifcity/msblues.html ] about 50 million years old. The white stars are massive, hotter, and younger, about 4 million years old. Radiating strongly in ultraviolet light, they represent a loose cluster [ http://www.seds.org/messier/cluster.html ] themselves, perhaps within 200 light-years of the main cluster. Massive stars [ http://antwrp.gsfc.nasa.gov/apod/ap960509.html ] which formed in the older main cluster have long since disappeared, ending their lives in spectacular supernova explosions [ http://antwrp.gsfc.nasa.gov/apod/ap970225.html ]. Did expanding debris from these supernovae trigger the formation [ http://antwrp.gsfc.nasa.gov/apod/ap000219.html ] of the nearby younger cluster? Probably so. In any event, a few million years from now a similar fate awaits the massive stars of the younger cluster - burning brightly but briefly before they explode sending new clouds of stellar debris [ http://antwrp.gsfc.nasa.gov/apod/ap990725.html ] into space. |
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ROSAT Explores The X-Ray Sky
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ROSAT Explores The X-Ray Sky |
| Explanation |
Launched in 1990, the orbiting ROSAT observatory [ http://heasarc.gsfc.nasa.gov/docs/rosat/rosat.html ] explored the Universe by viewing the entire sky in x-rays [ http://imagine.gsfc.nasa.gov/docs/science/know_l1/ history1_xray.html ] -- photons with about 1,000 times more energy than visible light. This ROSAT survey [ http://www.xray.mpe.mpg.de/rosat/survey/sxrb/12/ass.html ] produced the sharpest, most sensitive image of the x-ray sky to date. The all-sky image is shown with the plane of our Milky Way Galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap980523.html ] running horizontally through the center. Both x-ray brightness and relative energy are represented with red, green, and blue colors indicating three x-ray energy ranges (from lowest to highest). Bright x-ray spots near the galactic plane are within our own Milky Way. The brightest region (right of center) is toward the Vela Pulsar [ http://antwrp.gsfc.nasa.gov/apod/ap000609.html ] and the Puppis supernova remnant [ http://antwrp.gsfc.nasa.gov/apod/ap991209.html ]. Bright sources beyond our Galaxy are also apparent, notably the Virgo cluster of galaxies [ http://www.seds.org/messier/more/virgo.html ] (near top right) and the Large Magellanic Cloud (LMC) [ http://www.seds.org/messier/xtra/ngc/lmc.html ]. The LMC is easy to find here as several of the black stripes (blank areas caused by missing data) seem to converge on its position (lower right). Over large areas of the sky a general diffuse background of x-rays [ http://chandra.harvard.edu/press/00_releases/ press_011400bg.html ] dominates. Hot gas in our own Galaxy provides much of this background and gives rise to the grand looping structures [ http://antwrp.gsfc.nasa.gov/apod/ap990503.html ] visible in the direction of the galactic center (image center). Unresolved extragalactic sources also add to this background, particularly above and below the plane. Despite the x-ray sky's exotic appearance, a very familiar feature is visible - the gas and dust clouds which line the plane of our galaxy absorb x-rays as well as optical light and produce the dark bands running through the galactic center [ http://antwrp.gsfc.nasa.gov/apod/ap000629.html ]. |
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Dwarf Elliptical Galaxy NGC
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| Title |
Dwarf Elliptical Galaxy NGC 205 in the Local Group |
| Explanation |
Our Milky Way Galaxy [ http://antwrp.gsfc.nasa.gov/apod/milky_way.html ] is not alone. It is part of a gathering of about 25 galaxies known as the Local Group [ http://www.seds.org/messier/more/local.html ]. Members include the Great Andromeda Galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap991114.html ] (M31), M32 [ http://antwrp.gsfc.nasa.gov/apod/ap991103.html ], M33 [ http://antwrp.gsfc.nasa.gov/apod/ap980721.html ], the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap000222.html ], the Small Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap000430.html ], Dwingeloo 1 [ http://antwrp.gsfc.nasa.gov/apod/ap000109.html ], several small irregular galaxies [ http://www.seds.org/messier/irre.html ], and many dwarf elliptical [ http://nedwww.ipac.caltech.edu/level5/Ferguson/frames.html ] and dwarf spheroidal galaxies [ http://www.astro.uu.se/~ns/review.html ]. Pictured [ http://www.cfht.hawaii.edu/Science/Astros/Imageofweek/ciw061299.html ] on the lower left is one of the many dwarf ellipticals [ http://www.astro.psu.edu/users/pdurrell/dE.html ]: NGC 205 [ http://www.seds.org/messier/m/m110.html ]. Like M32 [ http://www.seds.org/messier/m/m032.html ], NGC 205 [ http://nedwww.ipac.caltech.edu/level5/Hodge/Hodge5_5.html ] is a companion to the large M31, and can sometimes be seen to the south of M31 [ http://www.seds.org/messier/m/m031.html ]'s center in photographs. The above image [ http://www.cfht.hawaii.edu/Science/Astros/Imageofweek/ciw061299.html ] shows NGC 205 to be unusual [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1998ApJ...499..209W ] for an elliptical galaxy [ http://antwrp.gsfc.nasa.gov/apod/elliptical_galaxies.html ] in that it contains at least two dust clouds [ http://antwrp.gsfc.nasa.gov/apod/ap990919.html ] (at 1 and 4 o'clock - they are visible but hard to spot) and signs of recent star formation [ http://antwrp.gsfc.nasa.gov/apod/stellar_nurseries.html ]. This galaxy is sometimes known as M110, although it was actually not part of Messier [ http://antwrp.gsfc.nasa.gov/apod/ap960626.html ]'s original catalog [ http://antwrp.gsfc.nasa.gov/apod/messier.html ]. |
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The First Lunar Observatory
| Title |
The First Lunar Observatory |
| Explanation |
The first, and so far only, lunar astronomical observatory [ http://snoopy.gsfc.nasa.gov/~lunartel/lunar1.html ] was deployed by the Apollo 16 [ http://antwrp.gsfc.nasa.gov/apod/ap960607.html ] crew in 1972. The Far Ultraviolet Camera / Spectrograph [ http://nssdc.gsfc.nasa.gov/nmc/tmp/1972-031C-10.html ] used a 3-inch diameter Schmidt telescope to photograph the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap000701.html ], nebulae [ http://nineplanets.org/twn/ ], star clusters [ http://www.allthesky.com/clusters/clusters.html ], and the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap000222.html ]. The tripod mounted astronomical equipment is seen above [ http://images.jsc.nasa.gov/images/pao/AS16/10075848.htm ], placed in the shadow of the Lunar Module [ http://www.nasm.edu/galleries/attm/nojs/ a11.am.lm.1.html ] (right) so it would not overheat. Also in the shadow is astronaut Charles Duke with the lunar rover [ http://antwrp.gsfc.nasa.gov/apod/ap990701.html ] in the background. The Far Ultraviolet Camera [ http://cass.jsc.nasa.gov/pub/expmoon/Apollo16/ A16_Experiments_UVC.html ] took pictures in ultraviolet light which would normally be blocked by the Earth's atmosphere. It was created by George Carruthers (NRL [ http://nrl.navy.mil/ ]), had a field of view of twenty degrees, and could detect stars having visual magnitude [ http://liftoff.msfc.nasa.gov/academy/universe/MAG.HTML ] brighter than eleven. One hundred seventy-eight images were recorded in a film cartridge which the astronauts returned to Earth. The observatory still stands on the Moon [ http://cass.jsc.nasa.gov/expmoon/lunar_missions.html ] today. |
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Small Galaxy NGC 4449
| Title |
Small Galaxy NGC 4449 |
| Explanation |
Grand spiral galaxies [ http://antwrp.gsfc.nasa.gov/apod/ap030524.html ] often seem to get all the glory. Their newly formed, bright, blue star clusters along beautiful, symmetric spiral arms are guaranteed to attract attention [ http://antwrp.gsfc.nasa.gov/apod/ap990402.html ]. But small irregular galaxies form stars too, like NGC 4449, located [ http://www.seds.org/~spider/spider/Misc/n4449.html ] about 12 million light-years away. The well-studied [ http://arxiv.org/abs/astro-ph/0010515 ] galaxy is similar in size, and often compared to our Milky Way's satellite galaxy, the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap060510.html ] (LMC). This lovely color image [ http://stargazer.christelhager.info/sonic/4449.html ] shows NGC 4449's general bar shape, also characteristic of the LMC, with scattered young blue star clusters. Near the bottom is the pinkish glow of atomic hydrogen gas, the telltale [ http://antwrp.gsfc.nasa.gov/apod/ap061123.html ] tracer of massive star forming regions. NGC 4449 is a member of a group of galaxies [ http://www.atlasoftheuniverse.com/galgrps/cvni.html ] found in the constellation Canes Venatici. In fact, interactions with nearby galaxies [ http://seds.org/MESSIER/galaxy.html ] are thought to have influenced star formation in NGC 4449. |
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New Stars Destroying NGC 174
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| Title |
New Stars Destroying NGC 1748 |
| Explanation |
NGC 1748 cannot contain all the new stars it has formed. The young stars, the most massive of which are bright blue [ http://antwrp.gsfc.nasa.gov/apod/ap010207.html ], emit so much energy they are pushing out and dispersing the gas and dust [ http://eta.pha.jhu.edu/~danforth/superfit/superfit.html ] that comprise this star forming nebula [ http://oposite.stsci.edu/pubinfo/PR/2001/11/pr-photos.html ]. Within only the past hundred thousand years, these stars have altered the bubble-like shape [ http://antwrp.gsfc.nasa.gov/apod/ap981118.html ] of the nebula and will likely destroy the nebula over the next few million years. Of particular interest [ http://arXiv.org/abs/astro-ph/0103414 ] is a bright region surrounded by a pink ring of dust [ http://antwrp.gsfc.nasa.gov/apod/ap980104.html ] and gas visible on the left of the above recently released picture [ http://hubble.esa.int/hubble/news/index.cfm?oid=26615 ] by the Hubble Space Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap970306.html ]. The center of this region is being evacuated by the wind [ http://www-spof.gsfc.nasa.gov/Education/wsolwind.html ] of the brightest star in the nebula. A lane of cooler dust connects NGC 1748 to a larger more diffuse nebula seen on the right. NGC 1748 [ http://oposite.stsci.edu/pubinfo/PR/2001/11/fastfacts.html ] spans about 25 light-years [ http://chandra.harvard.edu/photo/cosmic_distance.html ] in diameter and can be found in our galactic neighbor: the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap000222.html ]. |
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Star Cluster R136 Bursts Out
| Title |
Star Cluster R136 Bursts Out |
| Explanation |
In the center of star-forming region 30 Doradus [ http://www.seds.org/messier/xtra/ngc/n2070.html ] lies a huge cluster [ http://hubblesite.org/newscenter/newsdesk/archive/releases/1999/33/text/ ] of the largest, hottest, most massive stars known. These stars, known as the star cluster R136 [ http://antwrp.gsfc.nasa.gov/apod/ap010730.html ], and part of the surrounding nebula are captured here in this gorgeous visible-light image [ http://hubblesite.org/newscenter/newsdesk/archive/releases/1999/33/image/d ] from the Hubble Space Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap010806.html ]. Gas and dust [ http://antwrp.gsfc.nasa.gov/apod/ap030706.html ] clouds in 30 Doradus [ http://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search?30+Doradus ], also known as the Tarantula [ http://en.wikipedia.org/wiki/Tarantula ] Nebula, have been sculpted into elongated shapes by powerful winds [ http://www-spof.gsfc.nasa.gov/Education/wsolwind.html ] and ultraviolet radiation [ http://imagers.gsfc.nasa.gov/ems/uv.html ] from these hot cluster stars. The 30 Doradus Nebula [ http://antwrp.gsfc.nasa.gov/apod/ap030823.html ] lies within a neighboring galaxy, the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap040902.html ], located a mere 170,000 light-years [ http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question19.html ] away. |
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A Cerro Tololo Sky
| Title |
A Cerro Tololo Sky |
| Explanation |
High atop a Chilean [ http://www.cia.gov/cia/publications/factbook/geos/ci.html ] mountain lies one of the premier observatories of the southern sky: Cerro Tololo [ http://www.ctio.noao.edu/telescopes/TheFuture/crystal_ball.html ]. Pictured above is one of the premier telescopes [ http://www.berkeley.edu/news/media/releases/2001/03/22_halo.html ] of the Cerro Tololo Inter-American Observatory [ http://www.ctio.noao.edu/ ] (CTIO) and of the past quarter-century: the 4-meter Blanco Telescope [ http://www.ctio.noao.edu/telescopes/4m/base4m.html ]. Far behind the telescope are thousands of individual stars and diffuse light from three galaxies: the Small Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap000430.html ] (upper left), the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap000222.html ] (lower left), and our Milky Way Galaxy [ http://antwrp.gsfc.nasa.gov/apod/milky_way.html ] (right). Visible just to Blanco's right is the famous superposition [ http://www.southernskies.com.au/crux.htm ] of four bright stars known as the Southern Cross [ http://antwrp.gsfc.nasa.gov/apod/ap000618.html ]. The observatory structures are lit solely by starlight. |
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NGC 4449: Close-Up of a Smal
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| Title |
NGC 4449: Close-Up of a Small Galaxy |
| Explanation |
Grand spiral galaxies [ http://antwrp.gsfc.nasa.gov/apod/ap030524.html ] often seem to get all the glory. Their newly formed, bright, blue star clusters along beautiful, symmetric spiral arms [ http://antwrp.gsfc.nasa.gov/apod/ap070706.html ] are guaranteed to attract attention. But small irregular galaxies form stars too, like NGC 4449 [ http://www.seds.org/~spider/spider/Misc/n4449.html ], located about 12 million light-years away. In fact, this sharp Hubble [ http://heritage.stsci.edu/2007/26/ ] Space Telescope close-up of the well-studied [ http://arxiv.org/abs/astro-ph/0010515 ] galaxy clearly demonstrates that reddish star forming regions and young blue star clusters are widespread [ http://hubblesite.org/newscenter/archive/releases/2007/26/ image/a/format/zoom/ ]. Less than 20,000 light-years across, the small island universe is similar in size, and often compared [ http://heritage.stsci.edu/2007/26/supplemental.html ] to our Milky Way's satellite galaxy, the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap060510.html ]. NGC 4449 is a member of a group of galaxies [ http://www.atlasoftheuniverse.com/galgrps/cvni.html ] found in the constellation Canes Venatici. |
|
Tentacles of the Tarantula N
…
| Title |
Tentacles of the Tarantula Nebula |
| Explanation |
The largest, most violent star forming region known in the whole Local Group of galaxies [ http://en.wikipedia.org/wiki/Local_Group ] lies in our neighboring galaxy the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap060510.html ] (LMC). Were the Tarantula Nebula at the distance of the Orion Nebula [ http://antwrp.gsfc.nasa.gov/apod/ap060119.html ] -- a local star forming region -- it would take up fully half the sky. Also called 30 Doradus [ http://en.wikipedia.org/wiki/30_Doradus ], the red and pink gas indicates a massive emission nebula [ http://antwrp.gsfc.nasa.gov/apod/emission_nebulae.html ], although supernova remnants [ http://antwrp.gsfc.nasa.gov/apod/ap051202.html ] and dark nebula [ http://antwrp.gsfc.nasa.gov/apod/ap060409.html ] also exist there. The bright knot of stars left of center is called R136 [ http://antwrp.gsfc.nasa.gov/apod/ap051211.html ] and contains many of the most massive, hottest, and brightest stars known. The above image [ http://www.eso.org/public/outreach/press-rel/pr-2006/phot-50-06.html ] taken with the European Southern Observatory [ http://www.eso.org/public/about-eso/index.html ]'s (ESO's) Wide Field Imager [ http://www.ls.eso.org/lasilla/sciops/2p2/E2p2M/WFI/ ] is one of the most detailed ever [ http://www.eso.org/public/outreach/press-rel/pr-2006/pr-50-06.html ] of this vast star forming region. ESO has made it possible to fly around and into this detailed image by clicking here [ http://www.eso.org/public/outreach/press-rel/pr-2006/images/phot-50a-06-w0.html ]. |
|
Neighboring Galaxy: The Larg
…
| Title |
Neighboring Galaxy: The Large Magellanic Cloud |
| Explanation |
The brightest galaxy visible from our own Milky Way Galaxy is the Large Magellanic Cloud [ http://www.seds.org/messier/xtra/ngc/lmc.html ] (LMC). Visible predominantly from Earth's Southern Hemisphere [ http://antwrp.gsfc.nasa.gov/apod/ap001223.html ], the LMC [ http://antwrp.gsfc.nasa.gov/apod/ap980124.html ] is the second closest galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap970329.html ], neighbor [ http://antwrp.gsfc.nasa.gov/apod/ap980203.html ] to the Small Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap000430.html ], and one of eleven known dwarf galaxies [ http://www.astro.uu.se/~ns/mwsat.html ] that orbit our Milky Way Galaxy. The LMC [ http://www.astro.uni-bonn.de/~mcnews/MClinks.html ] is an irregular galaxy [ http://www.seds.org/messier/irre.html ] composed of a bar of older red stars, clouds of younger blue stars, and a bright red star forming region visible near the top of the above image [ http://www.noao.edu/image_gallery/html/im0562.html ] called the Tarantula Nebula [ http://antwrp.gsfc.nasa.gov/apod/ap991026.html ]. The brightest supernova [ http://imagine.gsfc.nasa.gov/docs/science/know_l1/supernovae.html ] of modern times, SN1987A [ http://antwrp.gsfc.nasa.gov/apod/ap000206.html ], occurred in the LMC [ http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?1969AJ.....74...44W ]. |
|
Halloween and the Ghost Head
…
| Title |
Halloween and the Ghost Head Nebula |
| Explanation |
Halloween's origin [ http://www.historychannel.com/exhibits/halloween/holiday_origins1.html ] is ancient and astronomical. Since the fifth century BC, Halloween [ http://en.wikipedia.org/wiki/Halloween ] has been celebrated as a cross-quarter day [ http://www-astronomy.mps.ohio-state.edu/~pogge/Ast161/Unit2/time.html ], a day halfway between an equinox [ http://antwrp.gsfc.nasa.gov/apod/ap000923.html ] (equal day / equal night) and a solstice [ http://antwrp.gsfc.nasa.gov/apod/ap971221.html ] (minimum day / maximum night in the northern hemisphere). With our modern calendar [ http://webexhibits.org/calendars/year-countries.html ], however, the real cross-quarter day [ http://www.whyy.org/tv12/franklinfacts/oct3100ff.html ] will occur next week. Another cross-quarter day is Groundhog's Day [ http://www.noblenet.org/year/groundhog.htm ]. Halloween's [ http://www.census.gov/Press-Release/www/releases/archives/facts_for_features_special_editions/010511.html ] modern celebration retains historic roots [ http://www.neopagan.net/Halloween-Origins.html ] in dressing to scare away the spirits of the dead. Perhaps a fitting modern tribute to this ancient holiday is the above-pictured Ghost Head Nebula [ http://photojournal.jpl.nasa.gov/catalog/PIA04226 ] taken with the Hubble Space Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap010806.html ]. Appearing similar to the icon of a fictional [ http://en.wikipedia.org/wiki/Casper_the_Friendly_Ghost ] ghost [ http://en.wikipedia.org/wiki/Ghost ], NGC 2080 is actually a star forming region [ http://antwrp.gsfc.nasa.gov/apod/stellar_nurseries.html ] in the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap010804.html ], a satellite galaxy of our own Milky Way Galaxy [ http://antwrp.gsfc.nasa.gov/apod/milky_way.html ]. The Ghost Head Nebula spans about 50 light-years [ http://chandra.harvard.edu/photo/cosmic_distance.html ] and is shown in representative colors. |
|
Halloween and the Ghost Head
…
| Title |
Halloween and the Ghost Head Nebula |
| Explanation |
Halloween's origin [ http://teacherlink.ed.usu.edu/TLresources/longterm/LessonPlans/Byrnes/halloween.html ] is ancient and astronomical. Since the fifth century BC, Halloween [ http://www.historychannel.com/exhibits/halloween/ ] has been celebrated as a cross-quarter day [ http://www-astronomy.mps.ohio-state.edu/~pogge/Ast161/Unit2/time.html ], a day halfway between an equinox [ http://antwrp.gsfc.nasa.gov/apod/ap000923.html ] (equal day / equal night) and a solstice [ http://antwrp.gsfc.nasa.gov/apod/ap971221.html ] (minimum day / maximum night in the northern hemisphere). With our modern calendar [ http://webexhibits.org/calendars/year-countries.html ], however, the real cross-quarter day [ http://www.whyy.org/tv12/franklinfacts/oct3100ff.html ] will occur next week. Another cross-quarter day is Groundhog's Day [ http://www.hansenplanetarium.net/CQGroundhog.html ]. Halloween's [ http://www.jpl.nasa.gov/proto/ halloween_sounds.html ] modern celebration retains historic roots [ http://www.utah.edu/planetarium/CQHalloween.html ] in dressing to scare away the spirits of the dead. A perhaps-fitting modern tribute to this ancient holiday is the above-pictured Ghost Head Nebula [ http://hubble.esa.int/hubble/news/image.cfm?oid=28749&ooid=28750 ] taken with the Hubble Space Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap010806.html ]. Appearing similar to the icon of a fictional ghost [ http://www.yesterdayland.com/popopedia/shows/saturday/sa1025.php ], NGC 2080 is actually a star forming region [ http://antwrp.gsfc.nasa.gov/apod/stellar_nurseries.html ] in the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap010804.html ], a satellite galaxy of our own Milky Way Galaxy [ http://antwrp.gsfc.nasa.gov/apod/milky_way.html ]. The Ghost Head Nebula spans about 50 light-years [ http://chandra.harvard.edu/photo/cosmic_distance.html ] and is shown in representative colors. |
|
Double Supernova Remnants DE
…
| Title |
Double Supernova Remnants DEM L316 |
| Explanation |
Are these two supernova shells related? To help find out, the 8-meter Gemini Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap030909.html ] located high atop a mountain in Chile [ http://en.wikipedia.org/wiki/Chile ] was pointed at the unusual, huge, double-lobed cloud dubbed DEM L316 [ http://adsabs.harvard.edu/abs/2005ApJ...635.1077W ]. The resulting image, shown above [ http://www.gemini.edu/index.php?option=content&task=view&id=265 ], yields tremendous detail. Inspection of the image as well as data taken [ http://chandra.harvard.edu/photo/2005/d316/ ] by the orbiting Chandra X-Ray Observatory [ http://chandra.harvard.edu/about/spacecraft.html ] indicate how different the two supernova remnants [ http://imagine.gsfc.nasa.gov/docs/science/know_l2/supernova_remnants.html ] are. In particular, the smaller shell appears to be the result of Type Ia supernova [ http://en.wikipedia.org/wiki/Type_Ia_supernova ] where a white dwarf [ http://antwrp.gsfc.nasa.gov/apod/ap050123.html ] exploded, while the larger shell appears to be the result of a Type II supernova [ http://en.wikipedia.org/wiki/Type_II_supernova ] where a massive normal star exploded. Since those two stellar types evolve on such different time scales [ http://instruct1.cit.cornell.edu/courses/astro101/java/evolve/evolve.htm ], they likely did not form together and so are likely not physically associated. Considering also that no evidence exists that the shell [ http://antwrp.gsfc.nasa.gov/apod/ap051226.html ]s are colliding, the two shells [ http://www.badastronomy.com/bablog/2008/01/11/aas-18-two-supernovae-no-waiting/ ] are now hypothesized to be superposed by chance. DEM L316 [ http://adsabs.harvard.edu/abs/2001PASJ...53...99N ] lies about 160,000 light years [ http://chandra.harvard.edu/photo/cosmic_distance.html ] away in the neighboring Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap060510.html ] (LMC) galaxy, spans about 140 light-years across, and appears toward the southern constellation of the Swordfish [ http://en.wikipedia.org/wiki/Swordfish ] (Dorado [ http://en.wikipedia.org/wiki/Dorado ]). |
|
A Southern Sky View
| Title |
A Southern Sky View |
| Explanation |
On 1996 March 22, a Galaxy and a comet shared the southern sky. They were captured together, from horizon to horizon, in the night sky above Loomberah, New South Wales, Australia [ http://www.cia.gov/cia/publications/factbook/geos/as.html ] by astronomer Gordon Garradd [ http://members.ozemail.com.au/~loomberah/ ]. Garradd used a home made all-sky camera with a fisheye lens [ http://www.zeta.org.au/~andrewa/ajaa31.htm ], resulting in a circular 200 degree field of view. This gorgeous sky view [ http://encke.jpl.nasa.gov/images/96B2/96B2_960322_gg1.txt ] was dominated by the luminous band of our Milky Way Galaxy [ http://antwrp.gsfc.nasa.gov/apod/milky_way.html ] cut by dramatic, dark interstellar dust clouds [ http://antwrp.gsfc.nasa.gov/apod/ap990919.html ]. Along with the bright stars of our Galaxy, the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap010804.html ] is visible at the lower left. That night sky was also graced by the long, lovely, bluish tail of Comet Hyakutake [ http://antwrp.gsfc.nasa.gov/apod/ap980717.html ], which can be seen toward the top of the image, near the bright star Arcturus [ http://www.astro.wisc.edu/~dolan/constellations/hr/5340.html ]. Bright city lights from nearby Tamworth [ http://www.tamworthonline.com.au/ ] glow along the Northwestern horizon. |
|
The Tarantula and the Supern
…
| Title |
The Tarantula and the Supernova |
| Explanation |
In this close-up of the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap950918.html ], the spidery looking nebula on the left is fittingly known as as the Tarantula nebula. It is an emission nebula [ http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#emis_neb ] surrounding a cluster of hot, young stars called the 30 Doradus super cluster. This cluster may contain the most massive stars known (about 50 times the mass of the Sun). Such massive stars put out more than 100 times as much energy as our Sun. The bright "star" (lower right) is actually Supernova 1987a [ http://antwrp.gsfc.nasa.gov/apod/ap950621.html ] and is a harbinger of things to come for the stars within the Tarantula. Massive stars burn their nuclear fuel at drastically enhanced rates to support their high energy output. As a result their lives last only a few million years compared to the Sun's few billions of years. They end in a spectacular death explosion, a supernova [ http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#sn ], like the star which exploded in 1987 as seen above. Supernovae may leave behind imploded stellar cores which form neutron stars [ http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#ns ] or black holes [ http://cossc.gsfc.nasa.gov/htmltest/rjn_bht.html ]. |
|
N44C: A Nebular Mystery
| Title |
N44C: A Nebular Mystery |
| Explanation |
Why is N44C [ http://heritage.stsci.edu/2002/12/table.html ] glowing so strangely? The star that appears to power the nebula, although young and bright, does not seem hot enough to create some of the colors observed. A search for a hidden hotter star in X-rays [ http://chandra.harvard.edu/xray_astro/xrays.html ] has come up empty. One hypothesis [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2000ApJ...545..251G ] is that the known central star has a neutron star [ http://www.astro.umd.edu/~miller/nstar.html ] companion in a very wide orbit [ http://antwrp.gsfc.nasa.gov/apod/ap970219.html ]. Hot X-rays might only then be emitted during brief periods [ http://www.astro.soton.ac.uk/~bexmgr/bex.html ] when the neutron star [ http://antwrp.gsfc.nasa.gov/apod/ap981128.html ] nears the known star and crashes through a disk of surrounding gas [ http://antwrp.gsfc.nasa.gov/apod/ap991219.html ]. Future observations might tell. N44C, pictured in the above [ http://heritage.stsci.edu/2002/12/index.html ] Hubble Space Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap010806.html ] image, is an emission nebula [ http://antwrp.gsfc.nasa.gov/apod/emission_nebulae.html ] in the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap010804.html ], a neighboring galaxy to our Milky Way Galaxy [ http://www.seds.org/messier/more/mw.html ]. Flowing filaments of colorful gas [ http://antwrp.gsfc.nasa.gov/apod/ap000521.html ] and dark dust [ http://antwrp.gsfc.nasa.gov/apod/ap011216.html ] far from the brightest region are likely part of the greater N44 complex [ http://www.sciam.com/exhibit/1999/070599telescopes/lasilla.html ]. It would take light about 125 years to cross N44C. |
|
N132D and the Color of X-Ray
…
| Title |
N132D and the Color of X-Rays |
| Explanation |
Supernova remnant N132D shows off complex structures in this sharp, color x-ray image [ http://chandra.harvard.edu/photo/2002/0050/index.html ]. Still, overall this cosmic debris [ http://antwrp.gsfc.nasa.gov/apod/ap960509.html ] from a massive star's explosive death has a strikingly simple horseshoe shape. While N132D [ http://chandra.harvard.edu/photo/0050/index.html ] lies 180,000 light-years distant in the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap010804.html ], the expanding [ http://antwrp.gsfc.nasa.gov/apod/ap011227.html ] remnant appears here about 80 light-years across. Light from the supernova blast [ http://chandra.harvard.edu/xray_sources/ supernovas.html ] which created it would have reached planet Earth about 3,000 years ago. Observed by the orbiting Chandra Observatory [ http://chandra.harvard.edu/chronicle/index.html ], N132D still glows in x-rays, its shocked gas [ http://antwrp.gsfc.nasa.gov/apod/ap000217.html ] heated to millions of degrees Celsius [ http://www.santesson.com/engtemp.html ]. Since x-rays are invisible [ http://imagine.gsfc.nasa.gov/docs/science/know_l1/ history1_xray.html ], the Chandra x-ray image data are represented in this picture by assigning visible colors to x-rays [ http://chandra.harvard.edu/photo/false_color.html ] with different energies. Low energy x-rays are shown as red, medium energy as green, and high energy as blue colors. These color choices make a pleasing picture and they also show the x-rays in the same energy order [ http://antwrp.gsfc.nasa.gov/apod/ap010511.html ] as visible light photons [ http://ethel.as.arizona.edu/~collins/astro/ subjects/electromag6.html ], which range from low to high energies as red, green, and blue. |
|
The Tarantula Zone
| Title |
The Tarantula Zone |
| Explanation |
The Tarantula Nebula [ http://www.seds.org/messier/xtra/ngc/n2070.html ] is more than 1,000 light-years across - a giant emission nebula within our neighboring galaxy the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap010804.html ]. Inside this cosmic arachnid lies a central young cluster of massive stars, cataloged as R136 [ http://antwrp.gsfc.nasa.gov/apod/ap010730.html ], whose intense radiation and strong winds have helped energize the nebular glow and shape the spidery filaments. In this impressive color mosaic [ http://www.eso.org/outreach/press-rel/pr-2002/ phot-14-02.html ] of images from the Wide-Field Imager [ http://www.ls.eso.org/lasilla/Telescopes/ 2p2T/E2p2M/WFI/ ] camera on ESO's 2.2 meter telescope at La Silla Observatory, other young star clusters can be seen still within the nebula's grasp [ http://antwrp.gsfc.nasa.gov/apod/ap990930.html ]. Also notable among the denizens [ http://antwrp.gsfc.nasa.gov/apod/ap990407.html ] of the Tarantula zone are several dark clouds [ http://antwrp.gsfc.nasa.gov/apod/ap010923.html ] invading the nebula's outer limits as well as the dense cluster of stars NGC 2100 at the extreme left edge of the picture. The small but expanding remnant of supernova 1987a [ http://antwrp.gsfc.nasa.gov/apod/ap990209.html ], the closest supernova in modern history, lies just off the lower right corner of the field. The rich mosaic's field of view covers an area on the sky about the size of the full moon in the southern constellation Dorado [ http://www.hawastsoc.org/deepsky/dor/ ]. |
|
LMC X-1: A Black Hole Candid
…
| Title |
LMC X-1: A Black Hole Candidate |
| Explanation |
The strongest source of X-rays [ http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#X-ray ] in the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap950918.html ] originates from an unusually energetic binary star system [ http://antwrp.gsfc.nasa.gov/apod/ap951226.html ]. This strong source, dubbed LMC X-1, is thought to be a normal and compact star orbiting each other. Gas [ http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#hydrogen ] stripped of the normal star falls onto the compact star, heats up, and emits X-rays. The X-rays shining from the system knock electrons off atoms for light years around, causing some atoms to glow noticeably in X-rays when the electrons re-combine. Motion in the binary system indicates the compact star is probably a black hole [ http://antwrp.gsfc.nasa.gov/apod/ap951127.html ], since its high mass - roughly five times that of our Sun [ http://antwrp.gsfc.nasa.gov/apod/ap950813.html ] - should be enough to cause even a neutron star [ http://antwrp.gsfc.nasa.gov/apod/ap951122.html ] to implode. |
|
A Cerro Tololo Sky
| Title |
A Cerro Tololo Sky |
| Explanation |
High atop a Chilean [ http://www.cia.gov/cia/publications/factbook/geos/ ci.html ] mountain lies one of the premier observatories of the southern sky: the Cerro Tololo Inter-American Observatory [ http://www.ctio.noao.edu/ ] (CTIO). Pictured above [ http://www.noao.edu/image_gallery/html/im0081.html ] is the dome surrounding one of the site's [ http://www.ctio.noao.edu/new/Sky%20Conditions/Webcam/ ] best known instruments, the 4-meter Blanco Telescope [ http://www.ctio.noao.edu/telescopes/4m/base4m.html ]. Far behind the dome are thousands of individual stars and diffuse light from three galaxies: the Small Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap000430.html ] (upper left), the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap000222.html ] (lower left), and our Milky Way Galaxy [ http://antwrp.gsfc.nasa.gov/apod/milky_way.html ] (right). Visible just to Blanco's right is the famous superposition [ http://www.southernskies.com.au/crux.htm ] of four bright stars known as the Southern Cross [ http://antwrp.gsfc.nasa.gov/apod/ap000618.html ]. A single 20 second exposure, this digital image was recorded with a sensitive detector intended for astronomical imaging. The observatory structures are lit solely by starlight. |
|
Supernova Remnant: Cooking E
…
| Title |
Supernova Remnant: Cooking Elements In The LMC |
| Explanation |
Massive stars cook elements in their cores through nuclear fusion [ http://fusedweb.pppl.gov/default.html ]. Starting with the light elements of hydrogen and helium, their central temperatures and pressures produce progressively heavier elements, carbon, oxygen, nitrogen, etc. up through iron. At the end of their lives they explode in a spectacular supernova [ http://antwrp.gsfc.nasa.gov/apod/ap951027.html ], scattering these elements into space, contributing material to the formation of other stars and star systems. In fact, the elements making up life on Earth were baked in such a stellar oven! This Hubble Space Telescope image [ http://www.stsci.edu/pubinfo/gif/N132D.txt ] of a supernova remnant known as N132D in the Large Magellanic Cloud (LMC) [ http://antwrp.gsfc.nasa.gov/apod/ap950918.html ] allows astronomers to explore the details [ http://casa.colorado.edu/casa/personnel/faculty/ morsey/papers/tmp/hst_v5submt/hst_v5submt.html ] of this nuclear processing and mixing. It reveals luminous clouds of cooked supernova debris energized by shocks -- singly ionized sulfur appears red, doubly ionized oxygen, green, and singly ionized oxygen, blue. The region shown above is about 50 lightyears across. |
|
Henize 70: A SuperBubble In
…
| Title |
Henize 70: A SuperBubble In The LMC |
| Explanation |
Massive stars [ http://antwrp.gsfc.nasa.gov/apod/ap951027.html ] (tens of times the mass of the Sun) profoundly affect their galactic environment. Churning and mixing the clouds of gas and dust between the stars, they leave their mark [ http://antwrp.gsfc.nasa.gov/apod/ap960509.html ] in the compositions and locations of future generations of stars and star systems. Dramatic evidence of this is beautifully illustrated in our neighboring galaxy, the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap950918.html ] (LMC), by the lovely ring shaped nebula, Henize [ http://spacsun.rice.edu/~henize/karlhenize.html ] 70 (also known as N70 and DEM301 [ http://www.ast.cam.ac.uk/~oey/thesisabs.html ]). It is actually a luminous "superbubble" of interstellar gas about 300 lightyears in diameter, blown by winds from hot, massive stars [ http://www.bartol.udel.edu/~cranmer/hotstar_home.html ] and supernova explosions [ http://legacy.gsfc.nasa.gov/docs/snr.html ], its interior filled with tenuous hot expanding gas. These superbubbles offer astronomers a chance to explore [ http://www.ast.cam.ac.uk/~oey/oeypubs.html ] this crucial connection between the lifecycles of stars and the evolution of galaxies. |
|
The First Lunar Observatory
| Title |
The First Lunar Observatory |
| Explanation |
The first and only lunar astronomical observatory was deployed by the Apollo 16 [ http://antwrp.gsfc.nasa.gov/apod/ap960607.html ] crew in 1972. The Far Ultraviolet Camera / Spectrograph [ http://www-sn.jsc.nasa.gov/explore/Data/Apollo/Part1/UVC.htm ] used a 3-inch diameter telescope to photograph the Earth [ http://images.jsc.nasa.gov/images/pao/AS16/10075874.htm ], various nebulae [ http://antwrp.gsfc.nasa.gov/apod/ap950925.html ], star clusters [ http://antwrp.gsfc.nasa.gov/apod/ap960221.html ], and the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap950918.html ]. The camera is seen above placed in the shadow of the Lunar Module [ http://www.nasm.edu/APOLLO/LMordered.html ] so it would not overheat. A leg of the Lunar Module enters the picture from the left. The camera took pictures in ultraviolet light which would normally be blocked by the Earth's atmosphere [ http://antwrp.gsfc.nasa.gov/apod/ap960527.html ]. The Far Ultraviolet Camera [ http://cass.jsc.nasa.gov/pub/expmoon/Apollo16/A16_Experiments_UVC.html ] was created by George Carruthers (NRL [ http://dsuap1.nrl.navy.mil/7609/home.html ]), had a field of view of 20 degrees, and could detect stars having visual magnitude [ http://liftoff.msfc.nasa.gov/academy/universe/MAG.HTML ] brighter than 11. 178 images were recorded in a film cartridge which was returned to Earth [ http://antwrp.gsfc.nasa.gov/apod/lib/earth.html ]. The observatory stands on the Moon [ http://antwrp.gsfc.nasa.gov/apod/lib/moon.html ] even today. |
|
A Magellanic Starfield
| Title |
A Magellanic Starfield |
| Explanation |
Stars of many types and colors are visible in this Hubble Space Telescope [ http://heritage.stsci.edu/1999/44/index.html ] close-up of a starfield in the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap980203.html ] (LMC). Over 10,000 stars are visible [ http://heritage.stsci.edu/1999/44/ supplemental.html ] -- the brightest of which are giant stars [ http://antwrp.gsfc.nasa.gov/apod/ap990605.html ]. Were our Sun [ http://www.seds.org/nineplanets/nineplanets/sol.html ] at the distance of these stars [ http://sciastro.astronomy.net/sci.astro.7.FAQ ], about 170,000 light-years, it would hardly be discernable. By contrast, only a few thousand individual stars [ http://antwrp.gsfc.nasa.gov/htmltest/gifcity/ msblues.html ] can be seen in the night sky with the unaided eye, and many of these lie within only a few hundred light-years. So typically, the light we see from nearby stars [ http://antwrp.gsfc.nasa.gov/apod/ap981025.html ] left during the age of our great-grand-parents, while light from LMC stars [ http://antwrp.gsfc.nasa.gov/apod/ap990221.html ] started its journey well before the dawn [ http://www.ucmp.berkeley.edu/ quaternary/ple.html ] of recorded human history. |
|
Superbubbles in the LMC
| Title |
Superbubbles in the LMC |
| Explanation |
Why is there a hole in the center of this nebula? A leading explanation is that it is caused by the stellar winds from the stars that live there. Stars [ http://antwrp.gsfc.nasa.gov/apod/ap960503.html ] - including the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap950813.html ] - expel electrons, protons, and other charged ions [ http://www-spof.gsfc.nasa.gov/Education/Ielect.html ] in a steady stream - the stellar wind [ http://www-spof.gsfc.nasa.gov/Education/wsolwind.html ]. The wind ions push out the normal hydrogen [ http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#hydrogen ] and helium [ http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#helium ] gas found glowing in the nebula. This star forming region is located in the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap950918.html ]. This picture [ http://www.astro.lsa.umich.edu:80/users/iotm/may96/n44.html ] is a composite of three separate photographs, each sensitive to only one specific color of light [ http://www.astro.washington.edu/strobel/lightnotes/lightnotes.html ] - a color that distinguishes a specific chemical element [ http://mwanal.lanl.gov/CST/imagemap/periodic/periodic.html ]. It is currently not known why stars emit a stellar wind. |
|
DEM L71: When Small Stars Ex
…
| Title |
DEM L71: When Small Stars Explode |
| Explanation |
Large, massive stars [ http://heasarc.gsfc.nasa.gov/docs/xmm_lc/edu/lessons/ background-lifecycles.html ] end their furious lives in spectacular supernova explosions [ http://stardate.org/resources/stars/wheeler.html ] -- but small, low mass stars may encounter a similar fate. In fact, instead of simply cooling off [ http://antwrp.gsfc.nasa.gov/apod/ap000910.html ] and quietly fading away, some white dwarf stars [ http://imagine.gsfc.nasa.gov/docs/science/know_l2/ dwarfs.html ] in binary star systems are thought to draw enough mass [ http://antwrp.gsfc.nasa.gov/apod/ap020927.html ] from their companions to become unstable, triggering a nuclear detonation [ http://cosmos.colorado.edu/astr1120/l6S4.htm ]. The resulting standard candle [ http://csep10.phys.utk.edu/astr162/lect/cosmology/ cosmicd.html ] stellar explosion is classified as a Type Ia supernova [ http://imagine.gsfc.nasa.gov/docs/science/know_l2/ supernovae.html ] and perhaps the best example yet of the aftermath is this expanding cloud of shocked stellar debris, DEM L71, in the nearby [ http://www.anzwers.org/free/universe/sattelit.html ] Large Magellanic Cloud. The sharp false-color x-ray image [ http://chandra.harvard.edu/photo/2003/deml71/index.html ] from the orbiting Chandra [ http://chandra.harvard.edu/about/emerson.html ] Observatory shows the predicted bright edges of the outer blast wave shock [ http://antwrp.gsfc.nasa.gov/apod/ap020223.html ] region and the x-ray glow of an inner region of reverse shock heated gas. Based on [ http://xxx.lanl.gov/abs/astro-ph/0212118 ] the Chandra data, estimates for the composition and total mass [ http://hyperphysics.phy-astr.gsu.edu/hbase/astro/ whdwar.html#c5 ] of expanding gas strongly suggest that this is all that remains of a white dwarf star. Light from this small star's self-destructive explosion would have first reached Earth several thousand years ago. |
|
ROSAT Explores the X-Ray Sky
| Title |
ROSAT Explores the X-Ray Sky |
| Explanation |
Launched in 1990, the orbiting ROSAT observatory [ http://legacy.gsfc.nasa.gov/docs/heasarc/missions/rosat.html ] explored the Universe by viewing the entire sky in x-rays [ http://heasarc.gsfc.nasa.gov/docs/learning_center/ basic/xray/xray_information.html ] - photons with about 1,000 times more energy than visible light [ http://heasarc.gsfc.nasa.gov/docs/learning_center/ basic/emspectrum.html ]. This ROSAT survey [ http://www.rosat.mpe-garching.mpg.de/survey/sxrb/ ] produced the sharpest, most sensitive image of the x-ray sky to date. The all-sky image is shown with the plane of our Milky Way Galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap960213.html ] running horizontally through the center. Both x-ray brightness and relative energy are represented with red, green, and blue colors indicating three x-ray energy ranges (from lowest to highest). Bright x-ray spots near the galactic plane are within our own Milky Way. The brightest region (right of center) is toward the Vela Pulsar and the Puppis supernova remnant [ http://lheawww.gsfc.nasa.gov/users/jonathan/outreach_pages/ neutron_stars.html ]. Bright sources beyond our Galaxy are also apparent, notably the Virgo cluster of galaxies [ http://antwrp.gsfc.nasa.gov/apod/ap960419.html ] (near top right) and the Large Magellanic Cloud (LMC) [ http://antwrp.gsfc.nasa.gov/apod/ap950918.html ]. The LMC is easy to find here as several of the black stripes (blank areas caused by missing data) seem to converge on its position (lower right). Over large areas of the sky a general diffuse background of x-rays dominates [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995ApJ%2E%2E%2E454%2E%2E643S&db_key=AST ]. Hot gas in our own Galaxy provides much of this background and gives rise to the grand looping structures visible in the direction of the galactic center (image center). Unresolved extragalactic sources also add to this background, particularly above and below the plane. Despite the x-ray sky's exotic appearance, a very familiar feature is visible - the gas and dust clouds which line the plane of our galaxy absorb x-rays as well as optical light and produce the dark bands running through the galactic center [ http://antwrp.gsfc.nasa.gov/apod/ap960605.html ]. |
|
Energized Nebula in the LMC
| Title |
Energized Nebula in the LMC |
| Explanation |
Blossoming in nearby galaxy the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap010804.html ] (LMC), this gorgeous nebula is energized by radiation and winds from a massive star whose surface temperature approaches 100,000 degrees. The composite color image [ http://www.eso.org/outreach/info-events/ut1fl/ ] from the European Southern Observatory's Melipal telescope [ http://antwrp.gsfc.nasa.gov/apod/ap000707.html ] resolves details in the energetic nebula, with emission from helium atoms in blue hues, oxygen atoms in green, and hydrogen atoms in red. While emission nebulae [ http://vis.sdsc.edu/research/hayden2.html ] generally show the familiar red light from ionized hydrogen atoms - hydrogen atoms with their electrons [ http://csep10.phys.utk.edu/astr162/lect/light/bohr.html ] stripped away - ionized helium atoms are tracers of even higher energy interactions. The intriguing filaments of helium emission make this and other recently studied emission nebulae [ http://www.eso.org/outreach/press-rel/pr-2003/ pr-08-03.html ] most exceptional. A Wolf-Rayet star [ http://antwrp.gsfc.nasa.gov/apod/ap030325.html ], the massive star powering this nebula, created a cosmic bubble [ http://antwrp.gsfc.nasa.gov/apod/ap021205.html ] with stellar winds in the early stages of its life. Part of the bubble is still apparent as the large arc in the lower portion of the image. The area pictured is about 150 light-years across. |
|
Denizen of the Tarantula Neb
…
| Title |
Denizen of the Tarantula Nebula |
| Explanation |
The star cluster at lower right, cataloged as Hodge 301 [ http://heritage.stsci.edu/1999/12/table.html ], is a denizen of the Tarantula Nebula [ http://antwrp.gsfc.nasa.gov/apod/ap020613.html ]. An evocative nebula in the southern sky, the sprawling cosmic Tarantula is an energetic star forming [ http://archive.ncsa.uiuc.edu/Cyberia/Bima/StarForm.html ] region some 168,000 light-years distant in our neighboring galaxy the Large Magellanic Cloud. The stars within Hodge 301 formed together tens of millions of years ago and as the massive ones quickly exhaust their nuclear fuel they explode. In fact, the giant stars of Hodge 301 [ http://pro.tok2.com/~aq6a-ink/mac/usa3d/hodge3d.htm ] are rapidly approaching this violent final phase of stellar evolution - known as a supernova [ http://archive.ncsa.uiuc.edu/Cyberia/Bima/StarDeath.html ]. These supernova blasts send material and shock waves back [ http://oposite.stsci.edu/pubinfo/pr/1998/08/ ] into the nebular gas to create the Tarantula's glowing filaments also visible in this Hubble Space Telescope Heritage image [ http://heritage.stsci.edu/1999/12/ ]. But these spectacular stellar death explosions signal star birth as well, as the blast waves condense gas and dust to ultimately form the next generation of stars inside the Tarantula Nebula [ http://antwrp.gsfc.nasa.gov/apod/ap010730.html ]. |
|
Massive Stars of 30 Doradus
| Title |
Massive Stars of 30 Doradus |
| Explanation |
In the center of star-forming region 30 Doradus [ http://www.seds.org/messier/xtra/ngc/n2070.html ] lies a huge cluster of the largest, hottest, most massive stars known. These stars and part of the surrounding nebula are captured here in this gorgeous visible-light Hubble Space Telescope image [ http://oposite.stsci.edu/pubinfo/pr/1999/33/pr-photos.html ]. Gas and dust clouds in 30 Doradus, also known as the Tarantula Nebula [ http://antwrp.gsfc.nasa.gov/apod/ap020613.html ], have been sculpted into elongated shapes by powerful winds and ultraviolet radiation from these hot cluster stars [ http://antwrp.gsfc.nasa.gov/apod/ap990221.html ]. Insets in the picture represent corresponding views from the Hubble's infrared camera [ http://www.stsci.edu/instruments/nicmos/ ] where each square measures 15.5 light-years [ http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question19.html ] across. Penetrating the obscuring dust [ http://antwrp.gsfc.nasa.gov/apod/ap990509.html ], these infrared images themselves offer detailed pictures of star formation within [ http://oposite.stsci.edu/pubinfo/pr/95/44.html ] the nebula's collapsing clouds, revealing the presence of newborn massive stars. The 30 Doradus Nebula [ http://antwrp.gsfc.nasa.gov/apod/ap991027.html ] lies within a neighboring galaxy, the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap010804.html ], located a mere 170,000 light-years away. |
|
N49's Cosmic Blast
| Title |
N49's Cosmic Blast |
| Explanation |
Scattered debris from a cosmic supernova explosion lights up the sky [ http://antwrp.gsfc.nasa.gov/apod/ap020809.html ] in this gorgeous composited image [ http://hubblesite.org/newscenter/ archive/2003/20/ ] based on data from the Hubble Space Telescope. Cataloged as N49, these glowing filaments of shocked gas span about [ http://hubblesite.org/newscenter/archive/2003/20/ fastfacts ] 30 light-years in our neighboring galaxy, the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap010804.html ]. Light from the original exploding star reached Earth thousands of years ago, but N49 also marks the location of another energetic outburst -- an extremely intense blast of gamma-rays [ http://cossc.gsfc.nasa.gov/epo/vu/overview/whatare/ whatare.html ] detected by satellites on March 5, 1979 [ http://solomon.as.utexas.edu/~duncan/magnetar.html#March5 ]. That date was the beginning of an exciting journey [ http://science.nasa.gov/newhome/headlines/ ast05mar99_1.htm ] in astrophysics which led researchers to the understanding of an exotic new class of stars. The source of the "March 5th Event" is now attributed to a magnetar [ http://solomon.as.utexas.edu/~duncan/magnetar.html ] - a highly magnetized, spinning neutron star also born in the ancient stellar explosion which created supernova remnant N49. The magnetar [ http://antwrp.gsfc.nasa.gov/apod/ap980527.html ] hurtles through the supernova debris [ http://antwrp.gsfc.nasa.gov/apod/ap011026.html ] cloud at over 1,200 kilometers per second. |
|
The Aquarius Dwarf
| Title |
The Aquarius Dwarf |
| Explanation |
Our Milky Way Galaxy [ http://antwrp.gsfc.nasa.gov/apod/milky_way.html ] is not alone. It is part of a gathering of about 50 galaxies known as the Local Group [ http://www.seds.org/messier/more/local.html ]. Members include the Great Andromeda Galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap021021.html ] (M31), M32 [ http://antwrp.gsfc.nasa.gov/apod/ap991103.html ], M33 [ http://antwrp.gsfc.nasa.gov/apod/ap021202.html ], the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap010804.html ], the Small Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap000430.html ], Dwingeloo 1 [ http://antwrp.gsfc.nasa.gov/apod/ap000109.html ], several small irregular galaxies [ http://www.seds.org/messier/irre.html ], and many dwarf elliptical [ http://nedwww.ipac.caltech.edu/level5/Ferguson/frames.html ] and dwarf spheroidal galaxies [ http://www.astro.uu.se/~ns/review.html ]. Pictured above is the Aquarius Dwarf [ http://www.seds.org/~spider/spider/LG/aqr_dw.html ], a faint dwarf irregular galaxy over 3 million light years [ http://chandra.harvard.edu/photo/cosmic_distance.html ] away. An earlier [ http://antwrp.gsfc.nasa.gov/apod/ap970329.html ] APOD [ http://antwrp.gsfc.nasa.gov/apod/ap960204.html ] erroneously identified [ http://www.solstation.com/x-objects/sag-deg.htm ] the above image as the Sagittarius Dwarf [ http://www.seds.org/messier/more/sagdeg.html ]. |
|
The Tarantula Zone
| Title |
The Tarantula Zone |
| Explanation |
The Tarantula Nebula [ http://www.seds.org/messier/xtra/ngc/n2070.html ] is more than 1,000 light-years across - a giant emission nebula within our neighboring [ http://www.anzwers.org/free/universe/ sattelit.html ] galaxy the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap010804.html ]. Inside this cosmic arachnid lies a central young cluster of massive stars, cataloged as R136 [ http://antwrp.gsfc.nasa.gov/apod/ap010730.html ], whose intense radiation and strong winds have helped energize the nebular glow and shape the spidery filaments. In this impressive color mosaic [ http://www.eso.org/outreach/press-rel/pr-2002/ phot-14-02.html ] of images from the Wide-Field Imager [ http://www.ls.eso.org/lasilla/Telescopes/ 2p2T/E2p2M/WFI/ ] camera on ESO's 2.2 meter telescope at La Silla Observatory, other young star clusters can be seen still within the nebula's grasp [ http://antwrp.gsfc.nasa.gov/apod/ap990930.html ]. Also notable among the denizens [ http://antwrp.gsfc.nasa.gov/apod/ap990407.html ] of the Tarantula zone are several dark clouds [ http://antwrp.gsfc.nasa.gov/apod/ap030620.html ] invading the nebula's outer limits as well as the dense cluster of stars NGC 2100 at the extreme left edge of the picture. The small but expanding remnant of supernova 1987a [ http://antwrp.gsfc.nasa.gov/apod/ap990209.html ], the closest supernova in modern history, lies just off the lower right corner of the field. The rich mosaic's field of view covers an area on the sky about the size of the full moon in the southern constellation Dorado [ http://www.hawastsoc.org/deepsky/dor/ ]. |
|
NGC1850: Star Cluster in the
…
| Title |
NGC1850: Star Cluster in the LMC |
| Explanation |
NGC1850 is a large cluster of stars located a mere 166,000 light-years from Earth [ http://web4.si.edu/hologlobe/si/earth.htm ] in our neighboring galaxy the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap961023.html ] (LMC). The colors in this beautiful Hubble Space Telescope composite image [ http://oposite.stsci.edu/pubinfo/PR/94/40.html ] of the cluster reveal different populations of stars. Yellowish stars are the main cluster stars, sun-like main sequence hydrogen burners [ http://antwrp.gsfc.nasa.gov/htmltest/gifcity/msblues.html ] about 50 million years old. The white stars are massive, hotter, and younger, about 4 million years old. Radiating strongly in ultraviolet light, they represent a loose cluster [ http://www.seds.org/messier/cluster.html ] themselves, perhaps within 200 light-years of the main cluster. Massive stars [ http://antwrp.gsfc.nasa.gov/apod/ap960509.html ] which formed in the older main cluster have long since disappeared, ending their lives in spectacular supernova explosions [ http://antwrp.gsfc.nasa.gov/apod/ap970225.html ]. Did expanding debris from these supernovae trigger the formation [ http://antwrp.gsfc.nasa.gov/apod/ap960625.html ] of the nearby younger cluster? Probably so. In any event, a few million years from now a similar fate awaits the massive stars of the younger cluster - burning brightly but briefly before they explode sending new clouds of stellar debris [ http://antwrp.gsfc.nasa.gov/apod/ap960307.html ] into space. |
|
NGC 604: Giant Stellar Nurse
…
| Title |
NGC 604: Giant Stellar Nursery |
| Explanation |
Stars are sometimes born in the midst of chaos. About 3 million years ago in the nearby galaxy M33 [ http://antwrp.gsfc.nasa.gov/apod/ap030924.html ], a large cloud of gas spawned dense internal knots which gravitationally collapsed to form stars. NGC 604 [ http://www.seds.org/messier/more/m033_n604.html ] was so large, however, it could form enough stars to make a globular cluster [ http://antwrp.gsfc.nasa.gov/apod/globular_clusters.html ]. Many young stars from this cloud are visible [ http://hubblesite.org/newscenter/newsdesk/archive/releases/2003/30/image/ ] in the above image [ http://heritage.stsci.edu/2003/30/caption.html ] from the Hubble Space Telescope [ http://www.stsci.edu/hst/HST_overview/ ], along with what is left of the initial gas cloud [ http://heritage.stsci.edu/2003/30/supplemental.html ]. Some stars were so massive they have already evolved and exploded in a supernova [ http://heasarc.gsfc.nasa.gov/docs/snr.html ]. The brightest stars [ http://antwrp.gsfc.nasa.gov/apod/ap021102.html ] that are left emit light so energetic that they create one of the largest cloud of ionized hydrogen [ http://antwrp.gsfc.nasa.gov/apod/ap030410.html ] gas known, comparable to the Tarantula Nebula [ http://antwrp.gsfc.nasa.gov/apod/ap030823.html ] in our Milky Way [ http://www.damtp.cam.ac.uk/user/gr/public/gal_milky.html ]'s close neighbor, the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap010804.html ]. |
|
N159 and the Papillon Nebula
| Title |
N159 and the Papillon Nebula |
| Explanation |
In a search for massive star [ http://antwrp.gsfc.nasa.gov/apod/ap990409.html ]s, the Hubble Space Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap010806.html ] has peered into yet another spectacular region of star formation [ http://antwrp.gsfc.nasa.gov/apod/ap011230.html ]. This nebula, known as N159 [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1996ApJ...465..738I ], spans over 150 light-years and is located in the neighboring Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap010804.html ] galaxy, about 170,000 light years [ http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question19.html ] distant. Visible in the above picture [ http://hubblesite.org/newscenter/newsdesk/archive/releases/1999/23/image/a ] are bright newborn stars [ http://antwrp.gsfc.nasa.gov/apod/ap031026.html ], dark filaments [ http://antwrp.gsfc.nasa.gov/apod/ap020703.html ] of dust [ http://antwrp.gsfc.nasa.gov/apod/ap030706.html ], and red-glowing hydrogen gas [ http://antwrp.gsfc.nasa.gov/apod/ap980828.html ]. The aptly named Papillon Nebula [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1999astro.ph..7149H ] (French for butterfly), is the unusual central compact cloud, highlighted in the inset. Reasons for the bipolar shape [ http://antwrp.gsfc.nasa.gov/apod/ap020106.html ] of the Papillon Nebula are currently unknown, but might indicate the presence of unseen high-mass star [ http://antwrp.gsfc.nasa.gov/apod/ap000611.html ]s and a thick gaseous disk [ http://antwrp.gsfc.nasa.gov/apod/ap030208.html ]. |
|
Structure in N63A
| Title |
Structure in N63A |
| Explanation |
Shells and arcs abound in this false-color, multiwavelength [ http://imagine.gsfc.nasa.gov/docs/science/know_l2/ multiwavelength.html ] view of supernova remnant N63A [ http://chandra.harvard.edu/photo/2003/n63a/ ], the debris of a massive stellar explosion. The x-ray emission [ http://arxiv.org/abs/astro-ph/0209370 ] (blue), is from gas heated to 10 million degrees C as knots of fast moving material from the cosmic blast [ http://chandra.harvard.edu/xray_sources/supernovas.html ] sweep up surrounding interstellar matter. Radio (red) and optical emission (green) are brighter near the central regions where the x-rays seem to be absorbed by denser, cooler material on the side of the expanding debris cloud facing the Earth. Located in the neighboring galaxy known as the Large Magellanic Cloud [ http://imagine.gsfc.nasa.gov/docs/science/know_l2/ multiwavelength.html ], the apparent [ http://chandra.harvard.edu/photo/ cosmic_lookback.html ] age [ http://chandra.harvard.edu/photo/0237/age.html ] of this supernova remnant is between 2,000 and 5,000 years, its extended glow spanning about 60 light-years. The intriguing image is a composite of [ http://chandra.harvard.edu/photo/2003/n63a/ more.html ] x-ray data from the orbiting Chandra Observatory [ http://chandra.harvard.edu/chronicle/index.html ], optical data from the Hubble Space Telescope [ http://hubblesite.org ], and radio from the Australia Telescope Compact Array [ http://www.narrabri.atnf.csiro.au/cgi-bin/Public/ atca_live.cgi ]. |
|
Colliding Supernova Remnants
| Title |
Colliding Supernova Remnants |
| Explanation |
When a massive star [ http://starchild.gsfc.nasa.gov/ ] exhausts its nuclear fuel it explodes [ http://antwrp.gsfc.nasa.gov/apod/ap970225.html ]. This stellar detonation, a supernova [ http://heasarc.gsfc.nasa.gov/docs/snr.html ], propels vast amounts of starstuff [ http://antwrp.gsfc.nasa.gov/apod/ap970424.html ] outwards, initially at millions of miles per hour. For another 100,000 years or so the expanding supernova remnant [ http://antwrp.gsfc.nasa.gov/apod/ap970803.html ] gradually slows as it sweeps up material and ultimately merges [ http://antwrp.gsfc.nasa.gov/apod/ap960509.html ] with the gas and dust of interstellar space. Short lived by cosmic standards, these stellar debris clouds are relatively rare and valuable objects for astronomers exploring the life cycles of stars [ http://suhep.phy.syr.edu/courses/PHY106/Termprojects/Projects/Stars/ ]. Yet this double bubble-shaped nebula [ http://www.astro.uiuc.edu/~rosanina/deml316_press.html ] 160,000 light-years away in the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap961023.html ] may represent something rarer still - the collision of two supernova remnants. This image in the light of excited Hydrogen atoms along with images [ http://www.astro.uiuc.edu/~rosanina/deml316.html ] at X-Ray, radio and other optical wavelengths [ http://heasarc.gsfc.nasa.gov/docs/learning_center/ introduction/emspectrum.html ], suggests that the bubbles are indeed two separate regions of hot gas surrounded by cooler dense shells begining to interact as they expand and make contact. |
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