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Hubble's Largest Galaxy Port
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| Title |
Hubble's Largest Galaxy Portrait Offers a New High-Definition View |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Giant galaxies weren?t assembled in a day. Neither was this Hubble Space Telescope image of the face-on spiral galaxy Messier 101 (M101). It is the largest and most detailed photo of a spiral galaxy that has ever been released from Hubble. The galaxy?s portrait is actually composed of 51 individual exposures taken with Hubble's Advanced Camera for Surveys and the Wide Field and Planetary Camera 2 in March 1994, September 1994, June 1999, November 2002, and January 2003. The newly composed image also includes elements from images from ground-based photos. |
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Hubble's Largest Galaxy Port
…
| Title |
Hubble's Largest Galaxy Portrait Offers a New High-Definition View |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. Giant galaxies weren?t assembled in a day. Neither was this Hubble Space Telescope image of the face-on spiral galaxy Messier 101 (M101). It is the largest and most detailed photo of a spiral galaxy that has ever been released from Hubble. The galaxy?s portrait is actually composed of 51 individual exposures taken with Hubble's Advanced Camera for Surveys and the Wide Field and Planetary Camera 2 in March 1994, September 1994, June 1999, November 2002, and January 2003. The newly composed image also includes elements from images from ground-based photos. |
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Happy Sweet Sixteen, Hubble
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| Title |
Happy Sweet Sixteen, Hubble Telescope! |
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M101: An Ultraviolet View
| Title |
M101: An Ultraviolet View |
| Explanation |
This picture of giant spiral galaxy Messier 101 (M101) [ http://www.seds.org/messier/m/m101.html ] was taken by the Ultraviolet Imaging Telescope [ http://hypatia.gsfc.nasa.gov/astro/uit/uit.html ] (UIT). UIT [ http://hypatia.gsfc.nasa.gov/astro/uit/uitcutaway.html ] flew into orbit as part of the Astro 2 mission [ http://www.ksc.nasa.gov/shuttle/missions/sts-67/mission-sts-67.html ] on-board the Space Shuttle Endeavour in March 1995. The image has been processed [ http://trifle.gsfc.nasa.gov/UIT/Astro2/Astro2_pictures.html ] so that the colors (dark purple through white) represent an increasing intensity of ultraviolet light [ http://imagine.gsfc.nasa.gov/docs/introduction/ emspectrum.html ]. Pictures of galaxies like this one show mainly clouds of gas containing newly formed stars many times more massive than the sun, which glow strongly in the ultraviolet. In contrast, visible light pictures of galaxies [ http://www.seds.org/messier/more/m101_more.html ] tend to be dominated by the yellow and red light of older stars. Ultraviolet light [ http://titan.srrb.noaa.gov/UV/ ], invisible to the human eye, is blocked by ozone in the atmosphere [ http://jwocky.gsfc.nasa.gov/ ] so ultraviolet pictures of celestial objects must be taken from space. M101 is a mere 22 million light-years away in the constellation Ursa Major [ http://www.seds.org/Maps/Stars_en/Fig/ursamajor.html ]. Its popular moniker is the Pinwheel Galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap970805.html ]. |
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Candidates for a Hypernova
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Candidates for a Hypernova |
| Explanation |
What created these huge explosion remnants? Speculation has been building recently that outbursts even more powerful than well-known supernovae [ http://antwrp.gsfc.nasa.gov/apod/ap961114.html ] might occur. Dubbed hypernovae [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1999ApJ...512L.117H ], these explosions might result from high-mass stars and liberate perhaps ten times more energy than conventional supernovae [ http://heasarc.gsfc.nasa.gov/docs/snr.html ]. A hypernova [ http://xxx.lanl.gov/abs/astro-ph/9712123 ] was originally postulated to explain the great amount of energy seemingly liberated in a gamma-ray burst [ http://antwrp.gsfc.nasa.gov/apod/ap970513.html ]. A search [ http://xxx.lanl.gov/abs/astro-ph/9903246 ] for visible remnants of hypernovae has now yielded the above two candidates [ ftp://PAO.GSFC.NASA.GOV/newsmedia/HEAD/HN/hypernova.html ]. Nearby spiral galaxy M101 [ http://antwrp.gsfc.nasa.gov/apod/ap970805.html ], shown on the right, has two large expanding shells that might have originated from a hypernova. Remnant NGC 5471B on the upper left and MF83 below were identified by the unusually high amount of X-ray radiation [ http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html ] they emit. MF83 is also one of the largest expanding shells [ http://antwrp.gsfc.nasa.gov/apod/ap990307.html ] ever found. Research continues into the possible nature and visibility of hypernovae and the gas shells they likely leave behind. |
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