|
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Andromeda Makes a Splash
| Title |
Andromeda Makes a Splash |
| Description |
This infrared composite image from NASA's Spitzer Space Telescope shows the Andromeda galaxy, a neighbor to our Milky Way galaxy. The main image (top) highlights the contrast between the galaxy's choppy waves of dust (red) and smooth sea of older stars (blue). The panels below the main image show the galaxy's older stars (left) and dust (right) separately. Spiral galaxies tend to form new stars in their dusty, clumpy arms, while their cores are populated by older stars. The Spitzer view also shows Andromeda's dust lanes twisting all the way into the center of the galaxy, a region that is crammed full of stars. In visible-light pictures, this central region tends to be dominated by starlight. Astronomers used these new images to measure the total infrared brightness of Andromeda. Because the amount of infrared light given off by stars depends on their masses, the brightness measurements provided a novel method for "weighing" the Andromeda galaxy. According to this method, the mass of the stars in Andromeda is about110 billion times that of the sun, which is in agreement with past calculations. This means the galaxy contains about one trillion stars (because most stars are actually less massive than the sun). For comparison, the Milky Way is estimated to hold about 400 billion stars. A small, companion galaxy called NGC 205 is visible above Andromeda. Another companion galaxy called M32 can also been seen below the galaxy. The Andromeda galaxy, also known affectionately by astronomers as Messier 31, is located 2.5 million light-years away in the constellation Andromeda. It is the closest major galaxy to the Milky Way, making it the ideal specimen for carefully examining the nature of galaxies. On a clear, dark night, the galaxy can be spotted with the naked eye as a fuzzy blob. Andromeda'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, the Milky Way is about 100,000 light-years across. When viewed from Earth, Andromeda occupies a portion of the sky equivalent to seven full moons. Because this galaxy is so large, the infrared images had to be stitched together out of about 3,000 separate Spitzer exposures. The light detected by Spitzer's infrared array camera at 3.6 and 4.5 microns is sensitive mostly to starlight and is shown in blue and green, respectively. The 8-micron light shows warm dust and is shown in red. The contribution from starlight has been subtracted from the 8-micron image to better highlight the dust structures. |
|
Andromeda Makes a Splash
| Title |
Andromeda Makes a Splash |
| Description |
This infrared composite image from NASA's Spitzer Space Telescope shows the Andromeda galaxy, a neighbor to our Milky Way galaxy. The main image (top) highlights the contrast between the galaxy's choppy waves of dust (red) and smooth sea of older stars (blue). The panels below the main image show the galaxy's older stars (left) and dust (right) separately. Spiral galaxies tend to form new stars in their dusty, clumpy arms, while their cores are populated by older stars. The Spitzer view also shows Andromeda's dust lanes twisting all the way into the center of the galaxy, a region that is crammed full of stars. In visible-light pictures, this central region tends to be dominated by starlight. Astronomers used these new images to measure the total infrared brightness of Andromeda. Because the amount of infrared light given off by stars depends on their masses, the brightness measurements provided a novel method for "weighing" the Andromeda galaxy. According to this method, the mass of the stars in Andromeda is about110 billion times that of the sun, which is in agreement with past calculations. This means the galaxy contains about one trillion stars (because most stars are actually less massive than the sun). For comparison, the Milky Way is estimated to hold about 400 billion stars. A small, companion galaxy called NGC 205 is visible above Andromeda. Another companion galaxy called M32 can also been seen below the galaxy. The Andromeda galaxy, also known affectionately by astronomers as Messier 31, is located 2.5 million light-years away in the constellation Andromeda. It is the closest major galaxy to the Milky Way, making it the ideal specimen for carefully examining the nature of galaxies. On a clear, dark night, the galaxy can be spotted with the naked eye as a fuzzy blob. Andromeda'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, the Milky Way is about 100,000 light-years across. When viewed from Earth, Andromeda occupies a portion of the sky equivalent to seven full moons. Because this galaxy is so large, the infrared images had to be stitched together out of about 3,000 separate Spitzer exposures. The light detected by Spitzer's infrared array camera at 3.6 and 4.5 microns is sensitive mostly to starlight and is shown in blue and green, respectively. The 8-micron light shows warm dust and is shown in red. The contribution from starlight has been subtracted from the 8-micron image to better highlight the dust structures. |
|
Andromeda Makes a Splash
| Title |
Andromeda Makes a Splash |
| Description |
This infrared composite image from NASA's Spitzer Space Telescope shows the Andromeda galaxy, a neighbor to our Milky Way galaxy. The main image (top) highlights the contrast between the galaxy's choppy waves of dust (red) and smooth sea of older stars (blue). The panels below the main image show the galaxy's older stars (left) and dust (right) separately. Spiral galaxies tend to form new stars in their dusty, clumpy arms, while their cores are populated by older stars. The Spitzer view also shows Andromeda's dust lanes twisting all the way into the center of the galaxy, a region that is crammed full of stars. In visible-light pictures, this central region tends to be dominated by starlight. Astronomers used these new images to measure the total infrared brightness of Andromeda. Because the amount of infrared light given off by stars depends on their masses, the brightness measurements provided a novel method for "weighing" the Andromeda galaxy. According to this method, the mass of the stars in Andromeda is about110 billion times that of the sun, which is in agreement with past calculations. This means the galaxy contains about one trillion stars (because most stars are actually less massive than the sun). For comparison, the Milky Way is estimated to hold about 400 billion stars. A small, companion galaxy called NGC 205 is visible above Andromeda. Another companion galaxy called M32 can also been seen below the galaxy. The Andromeda galaxy, also known affectionately by astronomers as Messier 31, is located 2.5 million light-years away in the constellation Andromeda. It is the closest major galaxy to the Milky Way, making it the ideal specimen for carefully examining the nature of galaxies. On a clear, dark night, the galaxy can be spotted with the naked eye as a fuzzy blob. Andromeda'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, the Milky Way is about 100,000 light-years across. When viewed from Earth, Andromeda occupies a portion of the sky equivalent to seven full moons. Because this galaxy is so large, the infrared images had to be stitched together out of about 3,000 separate Spitzer exposures. The light detected by Spitzer's infrared array camera at 3.6 and 4.5 microns is sensitive mostly to starlight and is shown in blue and green, respectively. The 8-micron light shows warm dust and is shown in red. The contribution from starlight has been subtracted from the 8-micron image to better highlight the dust structures. |
|
Andromeda Makes a Splash
| Title |
Andromeda Makes a Splash |
| Description |
This infrared composite image from NASA's Spitzer Space Telescope shows the Andromeda galaxy, a neighbor to our Milky Way galaxy. The main image (top) highlights the contrast between the galaxy's choppy waves of dust (red) and smooth sea of older stars (blue). The panels below the main image show the galaxy's older stars (left) and dust (right) separately. Spiral galaxies tend to form new stars in their dusty, clumpy arms, while their cores are populated by older stars. The Spitzer view also shows Andromeda's dust lanes twisting all the way into the center of the galaxy, a region that is crammed full of stars. In visible-light pictures, this central region tends to be dominated by starlight. Astronomers used these new images to measure the total infrared brightness of Andromeda. Because the amount of infrared light given off by stars depends on their masses, the brightness measurements provided a novel method for "weighing" the Andromeda galaxy. According to this method, the mass of the stars in Andromeda is about110 billion times that of the sun, which is in agreement with past calculations. This means the galaxy contains about one trillion stars (because most stars are actually less massive than the sun). For comparison, the Milky Way is estimated to hold about 400 billion stars. A small, companion galaxy called NGC 205 is visible above Andromeda. Another companion galaxy called M32 can also been seen below the galaxy. The Andromeda galaxy, also known affectionately by astronomers as Messier 31, is located 2.5 million light-years away in the constellation Andromeda. It is the closest major galaxy to the Milky Way, making it the ideal specimen for carefully examining the nature of galaxies. On a clear, dark night, the galaxy can be spotted with the naked eye as a fuzzy blob. Andromeda'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, the Milky Way is about 100,000 light-years across. When viewed from Earth, Andromeda occupies a portion of the sky equivalent to seven full moons. Because this galaxy is so large, the infrared images had to be stitched together out of about 3,000 separate Spitzer exposures. The light detected by Spitzer's infrared array camera at 3.6 and 4.5 microns is sensitive mostly to starlight and is shown in blue and green, respectively. The 8-micron light shows warm dust and is shown in red. The contribution from starlight has been subtracted from the 8-micron image to better highlight the dust structures. |
|
Exotic World Blisters Under
…
| Title |
Exotic World Blisters Under the Sun |
| Description |
This artist's concept shows a Jupiter-like planet soaking up the scorching rays of its nearby "sun." NASA's Spitzer Space Telescope used its heat-seeking infrared eyes to figure out that a gas-giant planet like the one depicted here is two-faced, with one side perpetually in the cold dark, and the other forever blistering under the heat of its star. The illustration portrays how the planet would appear to infrared eyes, showing temperature variations across its surface. The planet, called Upsilon Andromedae b, was first discovered in 1996 around the star Upsilon Andromedae, located 40 light-years away in the constellation Andromeda. This star also has two other planets orbiting farther out. Upsilon Andromedae b is what's known as a "hot-Jupiter" planet, because it is made of gas like our Jovian giant, and it is hot, due to its tight, 4.6-day-long jaunt around its star. The toasty planet orbits at one-sixth the distance of Mercury from our own sun. It travels in a plane that is seen neither edge- nor face-on from our solar system, but somewhere in between. Scientists do not know how fast Upsilon Andromedae b is spinning on its axis, but they believe that it is tidally locked to its star, just as our locked moon forever hides its "dark side" from Earth's view. Spitzer observed Upsilon Andromedae b at five points during the planet's trip around its star. The planet's light levels went up or down, as detected by Spitzer, depending on whether the planet's sunlit or dark side was pointed toward Earth. These data indicate that the temperature difference between the two hemispheres of the planet is about 1,400 degrees Celsius (2,550 degrees Fahrenheit). According to astronomers, this means that the side of the planet that faces the star is always as hot as lava, while the other side could potentially be as cold as ice. Specifically, the hot side of the planet ranges from about 1,400 to 1,650 degrees Celsius (2,550 to 3,000 degrees Fahrenheit), and the cold side from about minus 20 to 230 degrees Celsius (minus 4 to 450 degrees Fahrenheit). How can one side always be hot? The atmosphere of the planet must be absorbing and reradiating light fast enough that any heated gas circulating around the planet is cooled off before it reaches the dark side. |
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Hubble Discovers Black Holes
…
| Title |
Hubble Discovers Black Holes in Unexpected Places |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
|
Hubble Discovers Black Holes
…
| Title |
Hubble Discovers Black Holes in Unexpected Places |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
|
Hubble Discovers Black Holes
…
| Title |
Hubble Discovers Black Holes in Unexpected Places |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
|
Hubble Discovers Black Holes
…
| Title |
Hubble Discovers Black Holes in Unexpected Places |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
|
Hubble Discovers Black Holes
…
| Title |
Hubble Discovers Black Holes in Unexpected Places |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
|
Hubble Discovers Black Holes
…
| Title |
Hubble Discovers Black Holes in Unexpected Places |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
|
Hubble Discovers Black Holes
…
| Title |
Hubble Discovers Black Holes in Unexpected Places |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
|
Hubble Discovers Black Holes
…
| Title |
Hubble Discovers Black Holes in Unexpected Places |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
|
Hubble Discovers Black Holes
…
| Title |
Hubble Discovers Black Holes in Unexpected Places |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
|
Hubble Discovers Black Holes
…
| Title |
Hubble Discovers Black Holes in Unexpected Places |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
|
Hubble Finds Mysterious Disk
…
| Title |
Hubble Finds Mysterious Disk of Blue Stars Around Black Hole |
|
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 |
|
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. |
|
Where is Upsilon Andromedae?
| Title |
Where is Upsilon Andromedae? |
| Explanation |
Astronomers recently announced [ http://cfa-www.harvard.edu/afoe/upsAnd.html ] the detection of three large planets orbiting [ http://antwrp.gsfc.nasa.gov/apod/ap990416.html ] the star Upsilon Andromedae - the first planetary system known to orbit a normal star [ http://www.astro.psu.edu/users/pspm/arecibo/planets/planets.html ] other than our Sun. These planets were [ http://cfa-www.harvard.edu/afoe/espd.html ] not directly photographed but found through a Doppler technique developed to use large telescopes to search nearby stars [ http://www.sciam.com/explorations/052796explorations.html ] for wobbling planetary signatures. However, Upsilon And itself is visible to the unaided eye shining in Earth's sky in the northern constellation Andromeda [ http://cfa-www.harvard.edu/afoe/And.html ] at about 4th magnitude [ http://liftoff.msfc.nasa.gov/academy/universe/MAG.HTML ]. This deep photographic image [ http://aibn47.astro.uni-bonn.de/~gallery/constellations/ andromeda/constell.html ] shows Upsilon And along with fainter stars and "deep sky" objects including the famous Andromeda spiral galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap971101.html ] or M31 (right), the Triangulum galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap980721.html ] or M33 (below), and the star cluster NGC 752 [ http://www.seds.org/messier/xtra/ngc/n0752.html ] (left). About 44 light-years distant, Upsilon And is a star only a little more massive and just slightly hotter than the Sun. |
|
Upsilon Andromedae: An Extra
…
| Title |
Upsilon Andromedae: An Extra-Solar System |
| Explanation |
Yesterday, astronomers announced [ http://cfa-www.harvard.edu/afoe/upsAnd_pr.html ] the discovery of the first system of planets around a normal star other than our Sun [ http://www.seds.org/nineplanets/nineplanets/sol.html ]. Previously, only single planet star systems [ http://www.physics.sfsu.edu/~gmarcy/planetsearch/ ] had been found. Subtle changes in the wobble of Upsilon Andromedae [ http://www.physics.sfsu.edu/~gmarcy/planetsearch/upsand/upsand.html ], a Sun-like star in the constellation [ http://www.astro.wisc.edu/~dolan/constellations/extra/constellations.html ] of Andromeda [ http://www.astro.wisc.edu/~dolan/constellations/constellations/Andromeda.html ], allowed astronomers led by R. Paul Butler [ http://astro.berkeley.edu/~paul/vita.html ] (AAO [ http://www.aao.gov.au/aaohomepage.html ]) and Geoffrey W. Marcy [ http://cannon.sfsu.edu/~gmarcy/ ] (SFSU [ http://cannon.sfsu.edu/ ] /UCB [ http://astron.berkeley.edu/home.html ]) to make the breakthrough. This star system is quite different from our own Solar System [ http://antwrp.gsfc.nasa.gov/apod/ap980517.html ], however. All three detected planets have masses near or above Jupiter [ http://www.seds.org/nineplanets/nineplanets/jupiter.html ]. The discovery [ http://science.nasa.gov/newhome/headlines/ast15apr99_1.htm ] implies that multiple-planet systems [ http://antwrp.gsfc.nasa.gov/apod/ap961019.html ] are quite common, increasing speculation that life-bearing [ http://cmex-www.arc.nasa.gov/VikingCD/Puzzle/EvoLife.htm ] planets similar to Earth [ http://antwrp.gsfc.nasa.gov/apod/ap990131.html ] may one day be found. The drawing above is an artist's depiction of the Upsilon Andromedae [ http://antwrp.gsfc.nasa.gov/apod/ap990416.html http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1997ApJ...474L.119B ] system and its innermost planet. This planet orbits unexpectedly close to its parent star. |
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Exotic World Blisters Under
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PIA01938
| Title |
Exotic World Blisters Under the Sun |
| Original Caption Released with Image |
This artist's concept shows a Jupiter-like planet soaking up the scorching rays of its nearby "sun." NASA's Spitzer Space Telescope used its heat-seeking infrared eyes to figure out that a gas-giant planet like the one depicted here is two-faced, with one side perpetually in the cold dark, and the other forever blistering under the heat of its star. The illustration portrays how the planet would appear to infrared eyes, showing temperature variations across its surface. The planet, called Upsilon Andromedae b, was first discovered in 1996 around the star Upsilon Andromedae, located 40 light-years away in the constellation Andromeda. This star also has two other planets orbiting farther out. Upsilon Andromedae b is what's known as a "hot-Jupiter" planet, because it is made of gas like our Jovian giant, and it is hot, due to its tight, 4.6-day-long jaunt around its star. The toasty planet orbits at one-sixth the distance of Mercury from our own sun. It travels in a plane that is seen neither edge- nor face-on from our solar system, but somewhere in between. Scientists do not know how fast Upsilon Andromedae b is spinning on its axis, but they believe that it is tidally locked to its star, just as our locked moon forever hides its "dark side" from Earth's view. Spitzer observed Upsilon Andromedae b at five points during the planet's trip around its star. The planet's light levels went up or down, as detected by Spitzer, depending on whether the planet's sunlit or dark side was pointed toward Earth. These data indicate that the temperature difference between the two hemispheres of the planet is about 1,400 degrees Celsius (2,550 degrees Fahrenheit). According to astronomers, this means that the side of the planet that faces the star is always as hot as lava, while the other side could potentially be as cold as ice. Specifically, the hot side of the planet ranges from about 1,400 to 1,650 degrees Celsius (2,550 to 3,000 degrees Fahrenheit), and the cold side from about minus 20 to 230 degrees Celsius (minus 4 to 450 degrees Fahrenheit). How can one side always be hot? The atmosphere of the planet must be absorbing and reradiating light fast enough that any heated gas circulating around the planet is cooled off before it reaches the dark side. |
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