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Andromeda in Ultraviolet
In a break from its usual ta
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10/14/09
| Description |
In a break from its usual task of searching for distant cosmic explosions, NASA's Swift satellite acquired the highest-resolution view of a neighboring spiral galaxy ever attained in the ultraviolet. The galaxy, known as M31 in the constellation Andromeda, is the largest and closest spiral galaxy to our own. This mosaic of M31 merges 330 individual images taken by Swift's Ultraviolet/Optical Telescope. The image shows a region 200,000 light-years wide and 100,000 light-years high (100 arcminutes by 50 arcminutes). Image Credit: NASA/Swift/Stefan Immler (GSFC) and Erin Grand (UMCP) |
| Date |
10/14/09 |
|
Amazing Andromeda Galaxy
| Title |
Amazing Andromeda Galaxy |
| Description |
The many "personalities" of our great galactic neighbor, the Andromeda galaxy, are exposed in this new composite image from NASA's Galaxy Evolution Explorer and the Spitzer Space Telescope. The wide, ultraviolet eyes of Galaxy Evolution Explorer reveal Andromeda's "fiery" nature -- hotter regions brimming with young and old stars. In contrast, Spitzer's super-sensitive infrared eyes show Andromeda's relatively "cool" side, which includes embryonic stars hidden in their dusty cocoons. Galaxy Evolution Explorer detected young, hot, high-mass stars, which are represented in blue, while populations of relatively older stars are shown as green dots. The bright yellow spot at the galaxy's center depicts a particularly dense population of old stars. Swaths of red in the galaxy's disk indicate areas where Spitzer found cool, dusty regions where stars are forming. These stars are still shrouded by the cosmic clouds of dust and gas that collapsed to form them. Together, Galaxy Evolution Explorer and Spitzer complete the picture of Andromeda's swirling spiral arms. Hints of pinkish purple depict regions where the galaxy's populations of hot, high-mass stars and cooler, dust-enshrouded stars co-exist. Located 2.5 million light-years away, the Andromeda is our largest nearby galactic neighbor. The galaxy's entire disk spans about 260,000 light-years, which means that a light beam would take 260,000 years to travel from one end of the galaxy to the other. By comparison, our Milky Way galaxy's disk is about 100,000 light-years across. This image is a false color composite comprised of data from Galaxy Evolution Explorer's far-ultraviolet detector (blue), near-ultraviolet detector (green), and Spitzer's multiband imaging photometer at 24 microns (red). |
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The Trifid Nebula: Stellar S
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| Title |
The Trifid Nebula: Stellar Sibling Rivalry |
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Deepest View of Space Yields
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| Title |
Deepest View of Space Yields Young Stars in Andromeda Halo |
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Deepest View of Space Yields
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| Title |
Deepest View of Space Yields Young Stars in Andromeda Halo |
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Deepest View of Space Yields
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| Title |
Deepest View of Space Yields Young Stars in Andromeda Halo |
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Deepest View of Space Yields
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| Title |
Deepest View of Space Yields Young Stars in Andromeda Halo |
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Deepest View of Space Yields
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| Title |
Deepest View of Space Yields Young Stars in Andromeda Halo |
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Deepest View of Space Yields
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| Title |
Deepest View of Space Yields Young Stars in Andromeda Halo |
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Deepest View of Space Yields
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| Title |
Deepest View of Space Yields Young Stars in Andromeda Halo |
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Deepest View of Space Yields
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| Title |
Deepest View of Space Yields Young Stars in Andromeda Halo |
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Deepest View of Space Yields
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| Title |
Deepest View of Space Yields Young Stars in Andromeda Halo |
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Deepest View of Space Yields
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| Title |
Deepest View of Space Yields Young Stars in Andromeda Halo |
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Deepest View of Space Yields
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| Title |
Deepest View of Space Yields Young Stars in Andromeda Halo |
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Deepest View of Space Yields
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| Title |
Deepest View of Space Yields Young Stars in Andromeda Halo |
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Deepest View of Space Yields
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| Title |
Deepest View of Space Yields Young Stars in Andromeda Halo |
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Hubble Finds Mysterious Disk
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| Title |
Hubble Finds Mysterious Disk of Blue Stars Around Black Hole |
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Hubble Finds Mysterious Disk
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| Title |
Hubble Finds Mysterious Disk of Blue Stars Around Black Hole |
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Hubble Finds Mysterious Disk
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| Title |
Hubble Finds Mysterious Disk of Blue Stars Around Black Hole |
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Hubble Finds Mysterious Disk
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| Title |
Hubble Finds Mysterious Disk of Blue Stars Around Black Hole |
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Hubble Finds Mysterious Disk
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| Title |
Hubble Finds Mysterious Disk of Blue Stars Around Black Hole |
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Hubble Finds Mysterious Disk
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| Title |
Hubble Finds Mysterious Disk of Blue Stars Around Black Hole |
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Hubble Finds Mysterious Disk
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| Title |
Hubble Finds Mysterious Disk of Blue Stars Around Black Hole |
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Hubble Finds Mysterious Disk
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| Title |
Hubble Finds Mysterious Disk of Blue Stars Around Black Hole |
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Hubble Finds Mysterious Disk
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| Title |
Hubble Finds Mysterious Disk of Blue Stars Around Black Hole |
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The Tycho Catalog Skymap
| Title |
The Tycho Catalog Skymap |
| Abstract |
This image set is a skymap of stars from the Tycho and Hipparcos star catalogs. The maps are plotted in Platte-Carre projection (Cylindrical-Equidistant) using celestial coordinates making them suitable for mapping onto spheres in many popular animation programs. The stars are plotted as gaussian point-spread functions (PSF) so the size and amplitude of the stars corresponds to their relative intensity. The stars are also elongated in Right Ascension (celestial longitude) based on declination (celestial latitude) so stars in the polar regions will still be round when projected on a sphere. Stars fainter than the "threshold magnitude", usually selected as 5th magnitude, have their magnitude-intensity curve adjusted so they appear brighter than they really are. This makes the band of the Milky Way more visible. Stellar colors are assigned based on B and V magnitudes (B and V are stellar magnitudes measured through different filters). If Tycho B and V magnitudes are unavailable, Johnson B and V magnitudes are used instead. From these, an effective stellar temperature is derived using the algorithms described in Flower (ApJ 469, 355 1996). Corrections were noted from Siobahn Morgan (UNI). The effective temperature was then converted to CIE tristimulus X,Y,Z triples assuming a blackbody emission distribution. The X,Y,Z values are then converted to red-green-blue color pixels. About 2.4 million stars are plotted, but many may be below the pixel intensity resolution. The three most conspicuously missing objects on these maps are the Andromeda galaxy (M31) and the two Magellanic Clouds. [The images in this visualization were updated August 28, 2007 to fix a bug in the star generation algorithm.] |
| Completed |
2007-08-14 |
|
The Tycho Catalog Skymap
| Title |
The Tycho Catalog Skymap |
| Abstract |
This image set is a skymap of stars from the Tycho and Hipparcos star catalogs. The maps are plotted in Platte-Carre projection (Cylindrical-Equidistant) using celestial coordinates making them suitable for mapping onto spheres in many popular animation programs. The stars are plotted as gaussian point-spread functions (PSF) so the size and amplitude of the stars corresponds to their relative intensity. The stars are also elongated in Right Ascension (celestial longitude) based on declination (celestial latitude) so stars in the polar regions will still be round when projected on a sphere. Stars fainter than the "threshold magnitude", usually selected as 5th magnitude, have their magnitude-intensity curve adjusted so they appear brighter than they really are. This makes the band of the Milky Way more visible. Stellar colors are assigned based on B and V magnitudes (B and V are stellar magnitudes measured through different filters). If Tycho B and V magnitudes are unavailable, Johnson B and V magnitudes are used instead. From these, an effective stellar temperature is derived using the algorithms described in Flower (ApJ 469, 355 1996). Corrections were noted from Siobahn Morgan (UNI). The effective temperature was then converted to CIE tristimulus X,Y,Z triples assuming a blackbody emission distribution. The X,Y,Z values are then converted to red-green-blue color pixels. About 2.4 million stars are plotted, but many may be below the pixel intensity resolution. The three most conspicuously missing objects on these maps are the Andromeda galaxy (M31) and the two Magellanic Clouds. [The images in this visualization were updated August 28, 2007 to fix a bug in the star generation algorithm.] |
| Completed |
2007-08-14 |
|
The Tycho Catalog Skymap
| Title |
The Tycho Catalog Skymap |
| Abstract |
This image set is a skymap of stars from the Tycho and Hipparcos star catalogs. The maps are plotted in Platte-Carre projection (Cylindrical-Equidistant) using celestial coordinates making them suitable for mapping onto spheres in many popular animation programs. The stars are plotted as gaussian point-spread functions (PSF) so the size and amplitude of the stars corresponds to their relative intensity. The stars are also elongated in Right Ascension (celestial longitude) based on declination (celestial latitude) so stars in the polar regions will still be round when projected on a sphere. Stars fainter than the "threshold magnitude", usually selected as 5th magnitude, have their magnitude-intensity curve adjusted so they appear brighter than they really are. This makes the band of the Milky Way more visible. Stellar colors are assigned based on B and V magnitudes (B and V are stellar magnitudes measured through different filters). If Tycho B and V magnitudes are unavailable, Johnson B and V magnitudes are used instead. From these, an effective stellar temperature is derived using the algorithms described in Flower (ApJ 469, 355 1996). Corrections were noted from Siobahn Morgan (UNI). The effective temperature was then converted to CIE tristimulus X,Y,Z triples assuming a blackbody emission distribution. The X,Y,Z values are then converted to red-green-blue color pixels. About 2.4 million stars are plotted, but many may be below the pixel intensity resolution. The three most conspicuously missing objects on these maps are the Andromeda galaxy (M31) and the two Magellanic Clouds. [The images in this visualization were updated August 28, 2007 to fix a bug in the star generation algorithm.] |
| Completed |
2007-08-14 |
|
The Tycho Catalog Skymap
| Title |
The Tycho Catalog Skymap |
| Abstract |
This image set is a skymap of stars from the Tycho and Hipparcos star catalogs. The maps are plotted in Platte-Carre projection (Cylindrical-Equidistant) using celestial coordinates making them suitable for mapping onto spheres in many popular animation programs. The stars are plotted as gaussian point-spread functions (PSF) so the size and amplitude of the stars corresponds to their relative intensity. The stars are also elongated in Right Ascension (celestial longitude) based on declination (celestial latitude) so stars in the polar regions will still be round when projected on a sphere. Stars fainter than the "threshold magnitude", usually selected as 5th magnitude, have their magnitude-intensity curve adjusted so they appear brighter than they really are. This makes the band of the Milky Way more visible. Stellar colors are assigned based on B and V magnitudes (B and V are stellar magnitudes measured through different filters). If Tycho B and V magnitudes are unavailable, Johnson B and V magnitudes are used instead. From these, an effective stellar temperature is derived using the algorithms described in Flower (ApJ 469, 355 1996). Corrections were noted from Siobahn Morgan (UNI). The effective temperature was then converted to CIE tristimulus X,Y,Z triples assuming a blackbody emission distribution. The X,Y,Z values are then converted to red-green-blue color pixels. About 2.4 million stars are plotted, but many may be below the pixel intensity resolution. The three most conspicuously missing objects on these maps are the Andromeda galaxy (M31) and the two Magellanic Clouds. [The images in this visualization were updated August 28, 2007 to fix a bug in the star generation algorithm.] |
| Completed |
2007-08-14 |
|
The Tycho Catalog Skymap
| Title |
The Tycho Catalog Skymap |
| Abstract |
This image set is a skymap of stars from the Tycho and Hipparcos star catalogs. The maps are plotted in Platte-Carre projection (Cylindrical-Equidistant) using celestial coordinates making them suitable for mapping onto spheres in many popular animation programs. The stars are plotted as gaussian point-spread functions (PSF) so the size and amplitude of the stars corresponds to their relative intensity. The stars are also elongated in Right Ascension (celestial longitude) based on declination (celestial latitude) so stars in the polar regions will still be round when projected on a sphere. Stars fainter than the "threshold magnitude", usually selected as 5th magnitude, have their magnitude-intensity curve adjusted so they appear brighter than they really are. This makes the band of the Milky Way more visible. Stellar colors are assigned based on B and V magnitudes (B and V are stellar magnitudes measured through different filters). If Tycho B and V magnitudes are unavailable, Johnson B and V magnitudes are used instead. From these, an effective stellar temperature is derived using the algorithms described in Flower (ApJ 469, 355 1996). Corrections were noted from Siobahn Morgan (UNI). The effective temperature was then converted to CIE tristimulus X,Y,Z triples assuming a blackbody emission distribution. The X,Y,Z values are then converted to red-green-blue color pixels. About 2.4 million stars are plotted, but many may be below the pixel intensity resolution. The three most conspicuously missing objects on these maps are the Andromeda galaxy (M31) and the two Magellanic Clouds. [The images in this visualization were updated August 28, 2007 to fix a bug in the star generation algorithm.] |
| Completed |
2007-08-14 |
|
STEREO Coronal Mass Ejection
…
| Title |
STEREO Coronal Mass Ejection: From the EUVI to HI-2 |
| Abstract |
This movie collects imagery from SOHO and STEREO-A of a coronal mass ejection (CME) during January of 2007. The instruments in this view, from left to right, are STEREO/HI-1, STEREO/HI-2, SOHO/LASCO/C3, SOHO/LASCO/C2, and STEREO/EUVI. The Heliospheric Imager, HI-2, shows some of the tail of comet McNaught. The dark trapezoidal shape on the left edge of the image in HI-2 is the Earth occulter which will block out the disk of the Earth when it moves into view (since the planet will appear so bright as to saturate the detectors). Due to ongoing work with the STEREO coronagraphs, COR1 and COR2, the SOHO/LASCO coronagraphs are used for this movie. The blue Sun in the center of the coronagraphs is STEREO/EUVI ultraviolet images. There is a 22 hour gap in the data coverage for HI-2 which creates the appearance of a jump in the playback. These are not standard images but are called `running difference' images which highlight changes in the view. White pixels correspond to increases in brightness, while dark pixels reflect a decrease in brightness, with respect to the immediately previous image. 'Running differencing' generates some unusual effects. For example, the mottled background is created by the motion of the stars through the field-of-view as the spacecraft pointing direction slowly changes (the Andromeda galaxy is the oblong 'smudge' near the upper left corner). The planets Venus (right edge of HI-2) and Mercury are visible (near center of HI-1), their column of pixels saturated due to their brightness. * STEREO: Solar TErrestrial RElations Observatory * SOHO: SOlar Heliospheric Observatory * LASCO: Large Angle and Spectrometric Coronagraph * EUVI: Extreme UltraViolet Imager |
| Completed |
2007-02-26 |
|
STEREO Coronal Mass Ejection
…
| Title |
STEREO Coronal Mass Ejection: From the EUVI to HI-2 |
| Abstract |
This movie collects imagery from SOHO and STEREO-A of a coronal mass ejection (CME) during January of 2007. The instruments in this view, from left to right, are STEREO/HI-1, STEREO/HI-2, SOHO/LASCO/C3, SOHO/LASCO/C2, and STEREO/EUVI. The Heliospheric Imager, HI-2, shows some of the tail of comet McNaught. The dark trapezoidal shape on the left edge of the image in HI-2 is the Earth occulter which will block out the disk of the Earth when it moves into view (since the planet will appear so bright as to saturate the detectors). Due to ongoing work with the STEREO coronagraphs, COR1 and COR2, the SOHO/LASCO coronagraphs are used for this movie. The blue Sun in the center of the coronagraphs is STEREO/EUVI ultraviolet images. There is a 22 hour gap in the data coverage for HI-2 which creates the appearance of a jump in the playback. These are not standard images but are called `running difference' images which highlight changes in the view. White pixels correspond to increases in brightness, while dark pixels reflect a decrease in brightness, with respect to the immediately previous image. 'Running differencing' generates some unusual effects. For example, the mottled background is created by the motion of the stars through the field-of-view as the spacecraft pointing direction slowly changes (the Andromeda galaxy is the oblong 'smudge' near the upper left corner). The planets Venus (right edge of HI-2) and Mercury are visible (near center of HI-1), their column of pixels saturated due to their brightness. * STEREO: Solar TErrestrial RElations Observatory * SOHO: SOlar Heliospheric Observatory * LASCO: Large Angle and Spectrometric Coronagraph * EUVI: Extreme UltraViolet Imager |
| Completed |
2007-02-26 |
|
STEREO Coronal Mass Ejection
…
| Title |
STEREO Coronal Mass Ejection: From the EUVI to HI-2 |
| Abstract |
This movie collects imagery from SOHO and STEREO-A of a coronal mass ejection (CME) during January of 2007. The instruments in this view, from left to right, are STEREO/HI-1, STEREO/HI-2, SOHO/LASCO/C3, SOHO/LASCO/C2, and STEREO/EUVI. The Heliospheric Imager, HI-2, shows some of the tail of comet McNaught. The dark trapezoidal shape on the left edge of the image in HI-2 is the Earth occulter which will block out the disk of the Earth when it moves into view (since the planet will appear so bright as to saturate the detectors). Due to ongoing work with the STEREO coronagraphs, COR1 and COR2, the SOHO/LASCO coronagraphs are used for this movie. The blue Sun in the center of the coronagraphs is STEREO/EUVI ultraviolet images. There is a 22 hour gap in the data coverage for HI-2 which creates the appearance of a jump in the playback. These are not standard images but are called `running difference' images which highlight changes in the view. White pixels correspond to increases in brightness, while dark pixels reflect a decrease in brightness, with respect to the immediately previous image. 'Running differencing' generates some unusual effects. For example, the mottled background is created by the motion of the stars through the field-of-view as the spacecraft pointing direction slowly changes (the Andromeda galaxy is the oblong 'smudge' near the upper left corner). The planets Venus (right edge of HI-2) and Mercury are visible (near center of HI-1), their column of pixels saturated due to their brightness. * STEREO: Solar TErrestrial RElations Observatory * SOHO: SOlar Heliospheric Observatory * LASCO: Large Angle and Spectrometric Coronagraph * EUVI: Extreme UltraViolet Imager |
| Completed |
2007-02-26 |
|
STEREO Coronal Mass Ejection
…
| Title |
STEREO Coronal Mass Ejection: From the EUVI to HI-2 |
| Abstract |
This movie collects imagery from SOHO and STEREO-A of a coronal mass ejection (CME) during January of 2007. The instruments in this view, from left to right, are STEREO/HI-1, STEREO/HI-2, SOHO/LASCO/C3, SOHO/LASCO/C2, and STEREO/EUVI. The Heliospheric Imager, HI-2, shows some of the tail of comet McNaught. The dark trapezoidal shape on the left edge of the image in HI-2 is the Earth occulter which will block out the disk of the Earth when it moves into view (since the planet will appear so bright as to saturate the detectors). Due to ongoing work with the STEREO coronagraphs, COR1 and COR2, the SOHO/LASCO coronagraphs are used for this movie. The blue Sun in the center of the coronagraphs is STEREO/EUVI ultraviolet images. There is a 22 hour gap in the data coverage for HI-2 which creates the appearance of a jump in the playback. These are not standard images but are called `running difference' images which highlight changes in the view. White pixels correspond to increases in brightness, while dark pixels reflect a decrease in brightness, with respect to the immediately previous image. 'Running differencing' generates some unusual effects. For example, the mottled background is created by the motion of the stars through the field-of-view as the spacecraft pointing direction slowly changes (the Andromeda galaxy is the oblong 'smudge' near the upper left corner). The planets Venus (right edge of HI-2) and Mercury are visible (near center of HI-1), their column of pixels saturated due to their brightness. * STEREO: Solar TErrestrial RElations Observatory * SOHO: SOlar Heliospheric Observatory * LASCO: Large Angle and Spectrometric Coronagraph * EUVI: Extreme UltraViolet Imager |
| Completed |
2007-02-26 |
|
STEREO Coronal Mass Ejection
…
| Title |
STEREO Coronal Mass Ejection: From the EUVI to HI-2 |
| Abstract |
This movie collects imagery from SOHO and STEREO-A of a coronal mass ejection (CME) during January of 2007. The instruments in this view, from left to right, are STEREO/HI-1, STEREO/HI-2, SOHO/LASCO/C3, SOHO/LASCO/C2, and STEREO/EUVI. The Heliospheric Imager, HI-2, shows some of the tail of comet McNaught. The dark trapezoidal shape on the left edge of the image in HI-2 is the Earth occulter which will block out the disk of the Earth when it moves into view (since the planet will appear so bright as to saturate the detectors). Due to ongoing work with the STEREO coronagraphs, COR1 and COR2, the SOHO/LASCO coronagraphs are used for this movie. The blue Sun in the center of the coronagraphs is STEREO/EUVI ultraviolet images. There is a 22 hour gap in the data coverage for HI-2 which creates the appearance of a jump in the playback. These are not standard images but are called `running difference' images which highlight changes in the view. White pixels correspond to increases in brightness, while dark pixels reflect a decrease in brightness, with respect to the immediately previous image. 'Running differencing' generates some unusual effects. For example, the mottled background is created by the motion of the stars through the field-of-view as the spacecraft pointing direction slowly changes (the Andromeda galaxy is the oblong 'smudge' near the upper left corner). The planets Venus (right edge of HI-2) and Mercury are visible (near center of HI-1), their column of pixels saturated due to their brightness. * STEREO: Solar TErrestrial RElations Observatory * SOHO: SOlar Heliospheric Observatory * LASCO: Large Angle and Spectrometric Coronagraph * EUVI: Extreme UltraViolet Imager |
| Completed |
2007-02-26 |
|
STEREO Coronal Mass Ejection
…
| Title |
STEREO Coronal Mass Ejection: From the EUVI to HI-2 |
| Abstract |
This movie collects imagery from SOHO and STEREO-A of a coronal mass ejection (CME) during January of 2007. The instruments in this view, from left to right, are STEREO/HI-1, STEREO/HI-2, SOHO/LASCO/C3, SOHO/LASCO/C2, and STEREO/EUVI. The Heliospheric Imager, HI-2, shows some of the tail of comet McNaught. The dark trapezoidal shape on the left edge of the image in HI-2 is the Earth occulter which will block out the disk of the Earth when it moves into view (since the planet will appear so bright as to saturate the detectors). Due to ongoing work with the STEREO coronagraphs, COR1 and COR2, the SOHO/LASCO coronagraphs are used for this movie. The blue Sun in the center of the coronagraphs is STEREO/EUVI ultraviolet images. There is a 22 hour gap in the data coverage for HI-2 which creates the appearance of a jump in the playback. These are not standard images but are called `running difference' images which highlight changes in the view. White pixels correspond to increases in brightness, while dark pixels reflect a decrease in brightness, with respect to the immediately previous image. 'Running differencing' generates some unusual effects. For example, the mottled background is created by the motion of the stars through the field-of-view as the spacecraft pointing direction slowly changes (the Andromeda galaxy is the oblong 'smudge' near the upper left corner). The planets Venus (right edge of HI-2) and Mercury are visible (near center of HI-1), their column of pixels saturated due to their brightness. * STEREO: Solar TErrestrial RElations Observatory * SOHO: SOlar Heliospheric Observatory * LASCO: Large Angle and Spectrometric Coronagraph * EUVI: Extreme UltraViolet Imager |
| Completed |
2007-02-26 |
|
X For Andromeda
| Title |
X For Andromeda |
| Explanation |
A big beautiful spiral galaxy 2 million light-years away, Andromeda (M31) [ http://antwrp.gsfc.nasa.gov/apod/ap991114.html ] has long been touted as an analog to the Milky Way, a distant mirror of our own galaxy. The popular 1960s British sci-fi series, A For Andromeda [ http://www.cs.monash.edu.au/~lloyd/tildeImages/Film/ Andromeda/index.html ], even postulated that it was home to another technological civilization that communicated [ http://www.bigear.org/vol1no2/sagan.htm ] with us. Using the newly unleashed observing power of the orbiting Chandra [ http://antwrp.gsfc.nasa.gov/apod/ap990727.html ] X-ray telescope, astronomers have now imaged [ http://chandra.harvard.edu/press/00_releases/press_011400m31.html ] the center of our near-twin island universe [ ftp://crux.astr.ua.edu/web/goodies/data_resources/galaxies.text ], finding evidence for an object so bizarre it would have impressed many 60s science fiction [ http://www.magicdragon.com/UltimateSF/timeline1970.html ] writers (and readers). Like the Milky Way [ http://antwrp.gsfc.nasa.gov/apod/ap000120.html ], Andromeda's galactic center appears to harbor an X-ray source characteristic of a black hole [ http://chandra.harvard.edu/xray_sources/black_holes.html ] of a million or more solar masses. Seen above, the false-color X-ray picture [ http://chandra.harvard.edu/photo/cycle1/0007/index.html ] shows a number of X-ray sources, likely X-ray binary stars [ http://heasarc.gsfc.nasa.gov/docs/binary.html ], within Andromeda's central region as yellowish dots. The blue source located right at the galaxy's center is coincident with the position of the suspected massive black hole. While the X-rays [ http://chandra.harvard.edu/xray_astro/xrays.html ] are produced as material falls into the black hole and heats up, estimates from the X-ray data show Andromeda's central source to be surprisingly cool - only a million degrees or so compared to the tens of millions of degrees indicated for Andromeda's X-ray binaries [ http://antwrp.gsfc.nasa.gov/apod/ap991219.html ]. |
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Messier Marathon
| Title |
Messier Marathon |
| Explanation |
Gripped by an astronomical spring fever [ http://www.zzotto.com/rfc/CFTrip.htm ], it's once again time for many amateur stargazers to embark on a Messier Marathon [ http://www.seds.org/messier/xtra/marathon/marathon.html ]! The Vernal Equinox [ http://antwrp.gsfc.nasa.gov/apod/ap960922.html ] occurs March 20, marking the first day of Spring for the Northern Hemisphere. It also marks a favorable celestial situation [ http://www.reflector.org/MESSIER.HTM ] for potentially viewing all the objects in 18th century French astronomer Charles Messier's catalog [ http://www.seds.org/messier/xtra/history/biograph.html ] in one glorious dusk to dawn [ http://www.seds.org/messier/xtra/marathon/hall.html ] observing run. This year [ http://www.seds.org/messier/xtra/marathon/mm2000.html ] a bright full moon will interfere with dark skies near the actual equinox, so good nights near new moon for weekend marathoners are March 11/12 and April 1/2. (As an added bonus all the planets [ http://antwrp.gsfc.nasa.gov/apod/ap000310.html ] in the solar system can be viewed on these dates.) Astronomer Paul Gitto has created this masterful Messier Marathon [ http://www.cometman.com/messier.html ] grid with 11 rows and 10 columns of Messier catalog objects [ http://www.seds.org/messier/xtra/history/m-cat.html ]. In numerical order, the grid begins with M1, the Crab Nebula, [ http://antwrp.gsfc.nasa.gov/apod/ap960626.html ] at upper left and [ http://www.seds.org/messier/m/m102.html ] ends with M110 [ http://www.seds.org/messier/m/m110.html ], a small elliptical galaxy in Andromeda (lower right). Gitto's images were made with a digital camera and a 10-inch diameter reflecting telescope. |
|
The Comet and the Galaxy
| Title |
The Comet and the Galaxy |
| Explanation |
The Moon almost ruined this photograph. During late March and early April 1997, Comet Hale-Bopp [ http://www.jpl.nasa.gov/comet/ ] passed nearly in front of the Andromeda Galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap040718.html ]. Here the Great Comet of 1997 [ http://cometography.com/lcomets/1995o1.html ] and the Great Galaxy in Andromeda [ http://www.seds.org/messier/m/m031.html ] were photographed together [ http://antwrp.gsfc.nasa.gov/apod/ap970401.html ] on 1997 March 24th. The problem was the brightness of the Moon [ http://antwrp.gsfc.nasa.gov/apod/ap970924.html ]. The Moon [ http://www.seds.org/nineplanets/nineplanets/luna.html ] was full that night and so bright that long exposures meant to capture the tails of Hale-Bopp [ http://antwrp.gsfc.nasa.gov/apod/ap970416.html ] and the disk of M31 [ http://antwrp.gsfc.nasa.gov/apod/ap961011.html ] would capture instead only moonlight reflected off the Earth's atmosphere. By the time the Moon would set, this opportunity would be gone. That's why this picture was taken during a total lunar eclipse [ http://antwrp.gsfc.nasa.gov/apod/ap960926.html ]. |
|
Messier 110
| Title |
Messier 110 |
| Explanation |
This very sharp [ http://panther-observatory.com/gallery/deepsky/doc/ M110_cassf10.htm ] telescopic vista features the last object in the modern version of Charles Messier's catalog [ http://www.ngcic.org/dss/dss_messier.asp ] of bright clusters and nebulae - Messier 110 [ http://www.seds.org/messier/m/m110.html ]. A dwarf elliptical galaxy, M110 (aka NGC 205 [ http://antwrp.gsfc.nasa.gov/apod/ap001023.html ]) is actually a bright satellite of the large spiral galaxy Andromeda [ http://www.seds.org/messier/m/m031.html ], making M110 a fellow member of the local group [ http://www.atlasoftheuniverse.com/localgr.html ] of galaxies. Seen through a foreground of nearby stars, M110 is about 15,000 light-years across. That makes it comparable in size to satellite galaxies of our own Milky Way, the Large [ http://antwrp.gsfc.nasa.gov/apod/ap060510.html ] and Small [ http://antwrp.gsfc.nasa.gov/apod/ap050617.html ] Magellanic Clouds. Though elliptical [ http://antwrp.gsfc.nasa.gov/apod/ap060520.html ] galaxies are normally thought to be lacking in gas and dust to form new stars, M110 is known [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query? bibcode=1998ApJ...499..209W ] to contain young stars, and faint dust clouds can easily be seen in this detailed image at about the 7 and 11 o'clock positions relative to the galaxy center. |
|
M33: Spiral Galaxy in Triang
…
| Title |
M33: Spiral Galaxy in Triangulum |
| Explanation |
The small, northern constellation Triangulum [ http://www.hawastsoc.org/deepsky/tri/index.html ] harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy [ http://www.seds.org/messier/m/m033.html ]. M33 is over 50,000 light-years in diameter, third largest in the Local Group [ http://atlasoftheuniverse.com/localgr.html ] of galaxies after the Andromeda Galaxy (M31), and our own Milky Way. About 3 million light-years from the Milky Way, M33 is itself thought to be a satellite of the Andromeda Galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap021021.html ] and astronomers [ http://arxiv.org/abs/astro-ph?papernum=0506609 ] in these two galaxies would likely have spectacular views of each other's grand spiral star systems. As for the view from planet Earth, this detailed, wide field image [ http://www.tvdavisastropics.com/astroimages-1_00001f.htm ] nicely shows off M33's blue star clusters and pinkish star [ http://www.astropix.com/HTML/SHOW_DIG/031.HTM ] forming regions which trace the galaxy's loosely wound spiral arms. In fact, the cavernous NGC 604 [ http://antwrp.gsfc.nasa.gov/apod/ap021102.html ] is the brightest star forming region, seen here at about the 1 o'clock position from the galaxy center. Like M31, M33's population of well-measured variable stars have helped make this nearby spiral a cosmic yardstick [ http://cfa-www.harvard.edu/~kstanek/DIRECT/ ] for establishing [ http://adsabs.harvard.edu/cgi-bin/ bib_query?1926ApJ....63..236H ] the distance scale [ http://antwrp.gsfc.nasa.gov/diamond_jubilee/ debate96.html ] of the Universe. |
|
Messier 76
| Title |
Messier 76 |
| Explanation |
Nebula at the right foot of Andromeda [ http://en.wikipedia.org/wiki/Andromeda_(constellation) ] ... " begins the description for the 76th object in Charles Messier's 18th century Catalog of Nebulae and Star Clusters [ http://www.messiermarathon.com/messier's_catalogue.htm ]. In fact, M76 is [ http://www.seds.org/messier/m/m076.html ] one of the fainter objects on the Messier list and is also known by the popular name of the "Little Dumbbell Nebula". Like its brighter namesake M27 [ http://antwrp.gsfc.nasa.gov/apod/ap060803.html ] (the Dumbbell Nebula), M76 is recognized as a planetary nebula [ http://www.noao.edu/jacoby/pn_gallery.html ] - a gaseous shroud cast off by a dying sunlike star [ http://antwrp.gsfc.nasa.gov/apod/ap050123.html ]. The nebula itself is thought to be shaped more like a donut, while its box-like appearance [ http://antwrp.gsfc.nasa.gov/apod/ap021108.html ] is due to our nearly edge-on view. Gas expanding more rapidly away from the donut hole produces the faint loops of far flung material. The nebula's dying star can be picked out in this sharp color image [ http://www.photomeeting.de/astromeeting/ planetary/061017m76a_d.htm ] as the bottom, blue-tinted member of the double star near the center of the box-like shape. Distance estimates place M76 about 3 to 5 thousand light-years away, making the nebula over a light-year [ http://starchild.gsfc.nasa.gov/docs/StarChild/questions/ question19.html ] in diameter. |
|
Andromeda Island Universe
| Title |
Andromeda Island Universe |
| Explanation |
How far can you see? The most distant object easily visible to the unaided eye is M31 [ http://www.seds.org/messier/xtra/history/m-m31_42.html ], the great Andromeda Galaxy [ http://www.seds.org/messier/m/m031.html ] some two million light-years away. Without a telescope, even this immense spiral galaxy appears as an unremarkable, faint, nebulous cloud in the constellation Andromeda [ http://www.astronomical.org/constellations/and.html ]. But a bright yellow nucleus, dark winding dustlanes, gorgeous blue spiral arms and star clusters are recorded in this stunning telescopic digital [ http://www.geocities.com/CapeCanaveral/Hall/6432/ homepage.html ] mosaic of the nearby island universe. While even casual skygazers [ http://badastronomy.com/bitesize/galaxies.html ] are now inspired by the knowledge that there are many [ http://antwrp.gsfc.nasa.gov/apod/ap000709.html ] distant galaxies like M31, astronomers seriously debated [ http://adsbit.harvard.edu/cgi-bin/ nph-iarticle_query?1995PASP%2E%2E107%2E1133T ] this fundamental concept only 80 years ago. Were these "spiral nebulae" simply outlying components of our own Milky Way Galaxy or were they instead "island universes" -- distant systems of stars comparable to the Milky Way itself? This question was central to the famous Shapley-Curtis [ http://antwrp.gsfc.nasa.gov/diamond_jubilee/ debate20.html ] debate [ http://antwrp.gsfc.nasa.gov/diamond_jubilee/debate.html ] of 1920, which was later resolved by observations [ http://antwrp.gsfc.nasa.gov/apod/ap960406.html ] of M31 in favor of Andromeda, island universe [ http://www.astr.ua.edu/goodies/data_resources/galaxies.text ]. |
|
M31: The Andromeda Galaxy
| Title |
M31: The Andromeda Galaxy |
| Explanation |
Andromeda is the nearest major galaxy [ http://www.seds.org/messier/galaxy.html] to our own Milky Way Galaxy [ http://cassfos02.ucsd.edu/public/tutorial/MW.html ]. Our Galaxy is thought to look much like Andromeda [ http://antwrp.gsfc.nasa.gov/apod/ap020518.html ]. Together these two galaxies dominate the Local Group [ http://www.seds.org/messier/more/local.html ] of galaxies. The diffuse light from Andromeda [ http://www.seds.org/messier/m/m031.html ] is caused by the hundreds of billions of stars [ http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#star ] that compose it. The several distinct stars that surround Andromeda [ http://antwrp.gsfc.nasa.gov/apod/ap010917.html ]'s image are actually stars in our Galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap000518.html ] that are well in front of the background object. Andromeda [ http://www.noao.edu/image_gallery/html/im0424.html ] is frequently referred to as M31 since it is the 31st object [ http://antwrp.gsfc.nasa.gov/apod/ap960626.html ] on Messier [ http://www.seds.org/messier/xtra/history/biograph.html ]'s list of diffuse sky objects. M31 [ http://antwrp.gsfc.nasa.gov/apod/ap020412.html ] is so distant it takes about two million years for light to reach us from there. Although visible without aid, the above image [ http://www.robgendlerastropics.com/M31Page.html ] of M31 is a digital mosaic of 20 frames taken with a small telescope. Much about M31 remains unknown [ http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1995ApJ...444..157A ], including how the center acquired two nuclei [ http://antwrp.gsfc.nasa.gov/apod/ap961011.html ]. |
|
Dwarf Elliptical Galaxy NGC
…
| 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 ]. |
|
Moon Over Andromeda
| Title |
Moon Over Andromeda |
| Explanation |
The Great Spiral Galaxy in Andromeda [ http://antwrp.gsfc.nasa.gov/apod/ap051222.html ] (aka M31), a mere 2.5 million light-years distant [ http://arxiv.org/abs/astro-ph/0511045 ], is the closest large spiral to our own Milky Way. Andromeda is visible to the unaided eye as a small, faint, fuzzy patch, but because its surface brightness is so low, casual skygazers [ http://www.physics.ucla.edu/~huffman/m31.html ] can't appreciate the galaxy's impressive extent in planet Earth's sky. This entertaining composite image compares the angular size [ http://chandra.harvard.edu/photo/scale.html ] of the nearby galaxy to a brighter, more familiar celestial sight. In it, a deep exposure of Andromeda [ http://www.caelumobservatory.com/gallery/m31abtp.shtml ], tracing beautiful blue star clusters in spiral arms far beyond the bright yellow core, is combined with a typical view of a nearly full Moon. Shown at the same angular scale, the Moon covers about 1/2 degree on the sky, while the galaxy is clearly [ http://www.regulusastro.com/regulus/papers/ m31/ ] several times that size. The deep Andromeda exposure also includes two bright satellite galaxies, M32 [ http://antwrp.gsfc.nasa.gov/apod/ap991103.html ] and M110 [ http://antwrp.gsfc.nasa.gov/apod/ap060908.html ] (bottom). |
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Galaxy Group Hickson 44
| Title |
Galaxy Group Hickson 44 |
| Explanation |
Galaxies, like stars, frequently form groups. A group of galaxies [ http://www.seds.org/messier/gal_clus.html ] is a system containing more than two galaxies but less than the tens or hundreds typically found in a cluster of galaxies [ http://antwrp.gsfc.nasa.gov/apod/ap060321.html ]. A most notable example is the Local Group of Galaxies [ http://www.ucolick.org/~raja/AAS193_pressrel_cartoon.gif ], which houses over 30 galaxies [ http://seds.lpl.arizona.edu/messier/more/local.html ] including our Milky Way [ http://antwrp.gsfc.nasa.gov/apod/ap980523.html ], Andromeda [ http://antwrp.gsfc.nasa.gov/apod/ap061126.html ], and the Magellanic Clouds [ http://antwrp.gsfc.nasa.gov/apod/ap060806.html ]. Pictured above is nearby compact group [ http://www.astro.ubc.ca/people/hickson/hcg/ ] Hickson 44. This group [ http://members.aol.com/anonglxy/besthick.htm ] is located about 60 million light-years [ http://www.wsanford.com/~wsanford/exo/light-year.html ] away toward the constellation of Leo [ http://www.astro.wisc.edu/~dolan/constellations/constellations/Leo.html ]. Also known as the NGC 3190 Group, Hickson 44 [ http://www.rc-astro.com/photo/id1020.html ] contains several bright spiral [ http://www.seds.org/messier/spir.html ] galaxies and one bright elliptical [ http://www.seds.org/messier/elli.html ] galaxy on the upper left. The bright source on the upper right is a foreground star. Many galaxies in Hickson 44 [ http://www.skyhound.com/sh/archive/mar/HCG_44.html ] and other compact groups [ http://en.wikipedia.org/wiki/Groups_and_clusters_of_galaxies ] are either slowly merging or gravitationally pulling [ http://antwrp.gsfc.nasa.gov/apod/ap980110.html ] each other apart. |
|
Hale-Bopp: The Great Comet o
…
| Title |
Hale-Bopp: The Great Comet of 1997 |
| Explanation |
Ten short years ago, Comet Hale-Bopp [ http://www.cometography.com/lcomets/1995o1.html ] rounded the Sun and offered a dazzling spectacle in planet Earth's night. This stunning view [ http://www.astropix.com/HTML/SHOWCASE/970401.HTM ], recorded shortly after the comet's perihelion passage on April 1, 1997, features the memorable tails [ http://www.ifa.hawaii.edu/~jewitt/tail.html ] of Hale-Bopp -- a whitish dust tail and blue ion tail. Here, the ion tail extends well over ten degrees across the northern sky, fading near the double star clusters [ http://antwrp.gsfc.nasa.gov/apod/ap060413.html ] in Perseus, while the head of the comet lies near Almach [ http://www.astro.uiuc.edu/~kaler/sow/almach.html ], a bright star in the constellation Andromeda. Do you remember Hale-Bopp [ http://antwrp.gsfc.nasa.gov/apod/ap970416.html ]? The photographer's sons do, pictured in the foreground at ages 12 and 15. In all, Hale-Bopp [ http://antwrp.gsfc.nasa.gov/apod/ap970328.html ] was reported as visible to the naked eye from roughly late May 1996 through September 1997. |
|
Infrared Andromeda
| Title |
Infrared Andromeda |
| Explanation |
This wide, detailed Spitzer Space Telescope view [ http://www.spitzer.caltech.edu/Media/releases/ssc2006-14/ index.shtml ] features infrared light from dust (red) and old stars (blue) in Andromeda, a massive spiral galaxy a mere 2.5 million light-years away. In fact, with over twice the diameter of our own [ http://antwrp.gsfc.nasa.gov/apod/ap050825.html ] Milky Way, Andromeda is [ http://www.seds.org/Messier/m/m031.html ] the largest nearby [ http://www.seds.org/Messier/more/ local.html ] galaxy. Andromeda's population of bright young stars define its sweeping spiral arms in visible light images [ http://antwrp.gsfc.nasa.gov/apod/ap051222.html ], but here the infrared view clearly follows the lumpy dust lanes heated by the young stars as they wind even closer to the galaxy's core [ http://antwrp.gsfc.nasa.gov/apod/ap041227.html ]. Constructed to explore [ http://nedwww.ipac.caltech.edu/level5/ANDROMEDA_Atlas/ Hodge_contents.html ] Andromeda's infrared brightness [ http://coolcosmos.ipac.caltech.edu// ] and stellar populations, the full mosaic image is composed of about 3,000 individual frames. Two smaller companion galaxies, NGC 205 [ http://antwrp.gsfc.nasa.gov/apod/ap001023.html ] (below) and M32 [ http://antwrp.gsfc.nasa.gov/apod/ap991103.html ] (above) are also included in the combined fields. The data confirm that Andromeda (aka M31) houses around 1 trillion [ http://kokogiak.com/megapenny/thirteen.asp ] stars, compared to [ http://astronomy.swin.edu.au/~gmackie/billions.html ] 4 hundred billion [ http://kokogiak.com/megapenny/nine.asp ] for the Milky Way. |
|
Southwest Andromeda
| Title |
Southwest Andromeda |
| Explanation |
This new image composite [ http://www.subaru.naoj.org/Latestnews/200109/M31/index.html ] of the southwest region of M31 [ http://antwrp.gsfc.nasa.gov/apod/ap991114.html ] from the Subaru Telescope [ http://www.subaru.naoj.org/Introduction/outline.html ] shows many stars, nebulae, and star clusters never before resolved. An older population of stars near Andromeda's center [ http://antwrp.gsfc.nasa.gov/apod/ap961011.html ] causes the yellow hue visible on the upper right. Young blue stars stand out in the spiral arms [ http://fuse.pha.jhu.edu/~danforth/spiral/ ] on the lower left. Red emission nebula [ http://antwrp.gsfc.nasa.gov/apod/emission_nebulae.html ], blue open clusters [ http://antwrp.gsfc.nasa.gov/apod/open_clusters.html ] of stars, and sweeping lanes of dark dust [ http://antwrp.gsfc.nasa.gov/apod/ap990509.html ] punctuate the swirling giant. Andromeda [ http://www.seds.org/messier/m/m031.html ], at about 2.5 million light years [ http://chandra.harvard.edu/photo/cosmic_distance.html ] distant, and our Milky Way [ http://antwrp.gsfc.nasa.gov/apod/milky_way.html ] are the largest galaxies [ http://www.seds.org/messier/galaxy.html ] in the Local Group of Galaxies [ http://www.seds.org/messier/more/local.html ]. Understanding M31 [ http://antwrp.gsfc.nasa.gov/apod/ap000908.html ] helps astronomers to understand our own Milky Way Galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap000130.html ], since the two are so similar. |
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