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Hubble Heritage Archive - 2001 Hubble Heritage Archive: 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 Gemini | Apollo | Hubble Space Telescope
Hubble Heritage Picture - January 2001
This glowing gas cloud represents one of the most active star-forming regions of NGC 6822, much like the Orion Nebula in the Milky Way, but on a much larger scale. There are thousands of stars in this cloud, many of which are visible as bright white dots. The "X" is a Roman Numeral designation. Gas clouds in NGC 6822 have held astronomers' interests since their discovery by E. E. Barnard in 1881. Edwin Hubble used the 100 in. telescope at Mount Wilson Observatory in 1925 to make the first detailed photographic investigation of NGC 6822. This image shows details too fine to be resolved from ground-based telescopes. Hubble Heritage Picture - February 2001 February's Hubble Heritage image is of Menzel 3, AKA the Ant Nebula, a planetary nebula. 3,000 light-years from us, the Ant Nebula lies in the constellation Norma; this image shows the nebula to be approximately 1 arcminute across (1.6 light-years). The image was originally taken on July 20, 1997, and June 30, 1998, for a total exposure time of 1.7 hours. Images of planetary nebulae such as this directly challenge the ideas of planetary nebula formation. Scientists used to believe that such symmetrical patterns could not arise from the chaotic explosion that ends a sun-like star's life. However, the strikingly symmetric patterns shown in this image and others like it demonstrate that such a seemingly chaotic system can give rise to order. One possible scenario is that the central star in this case has a closely orbiting (at least 1 A.U.) companion that is close enough to exert strong tidal forces which shape the out flowing gas. A second possibility is that the dying star's strong magnetic fields are wound into complex shapes - like spaghetti in an eggbeater. Strong, dense solar winds flow from the star, following the twisted field lines, and are made visible by ultraviolet light from the central star or gas in the vicinity. Hubble Heritage Picture - March 2001
This view of a perfectly edge-on spiral galaxy reveals the intricate structure of gas and dust in the galaxy's disk as well as above and below the plane of the galaxy. The dark clouds of interstellar medium absorb visible light, and so the swath that is about 500 light-years thick appears to cut the galaxy in half. Large dust clouds are believed to lie where new stars form. As the stars start to glow, they cause their parent nebula to evaporate away, revealing the new stars that were previously hidden. There are a few examples of this in NGC 4013 along the band of the galaxy. Note that the very bright star near the top left of the image is a foreground star in the Milky Way and so is not associated with NGC 4013. Hubble Heritage Picture - April 2001 April's Hubble Heritage image is of NGC 5194, AKA M51, AKA the Whirlpool Galaxy, a face-on spiral galaxy with a companion (companion not visible). 31 million light-years from us, the Whirlpool galaxy lies in the constellation Canes Venatici; this image covers approximately 30,000 light-years down. The image was originally taken on January 15 and 24, 1995, and July 21, 1999, for a total exposure time of 5.7 hours. The birth place of massive, luminous stars, the Whirlpool galaxy has been one of the most photogenic galaxies in amateur and professional astronomy. It has been studied extensively in a range of wavelengths by ground- and space-based observatories. This is a composite image of visible light and light from glowing hydrogen. M51 is currently involved in a close encounter with the companion galaxy NGC 5195 (just above the image). The companion galaxy is triggering the large amount of star formation, highlighted by the myriad of luminous clusters and individual stars, most highlighted in red because of their association with glowing hydrogen gas. Due to the high resolution offered by the orbiting telescope, intricate structure can be seen for the first time in the dust clouds. The regularity and large number of dark "spurs" seen branching from the main spiral arms suggests that previous models of "two-arm" spiral galaxies may need to be revisited. The new images also reveal dust in the nucleus - this may be fuel for a large black hole. The team is also studying this galaxy at near-infrared wavelengths with another instrument on Hubble. At these wavelengths, the dusty clouds are more transparent and the true distribution of stars is more easily seen. In addition, regions of star formation that are obscured in the optical images are seen in the near-infrared images. Hubble Heritage Picture - May 2001
This release of one of the most photographed objects in the sky is being released to celebrate the Hubble Space Telescope's (HST) 11th anniversary. Internet voters selected it for the HST to view. The horse's head is actually a dark nebula, Barnard 33, which has no internal source of illumination. It lies, however, against the backdrop of the bright nebula IC 434. It was original discovered in the late 1800's. Hubble Heritage Picture - June 2001 June's Hubble Heritage image is of Saturn. Saturn is an average of 9.5 A.U. from the sun, and it ranges from about 8.5-10.5 A.U. from Earth. The images were taken in October 1996, October 1997, October 1998, November 1999, and November 2000. Saturn's equator is tilted relative to its orbit by 27° - similar to Earth's 23.4° axial tilt - which causes the seasons. Thus, as Saturn orbits the sun, it tilts its hemispheres towards Earth in a changing manner. This is very well demonstrated by Saturn (it happens in almost every other planet, as well) due to the remarkable ring structure. In the lower left, the first image, the image is of shortly after the autumn equinox in Saturn's Northern Hemisphere. The top right image is approaching the winter solstice in the Northern Hemisphere. Astronomers use image sets like this to study the variations in color and brightness of the rings in order to learn more about the rings' composition, formation, and to estimate their longevity. For more information on Saturn and its rings, view the Saturn page of this site. Hubble Heritage Picture - July 2001
In this sharpest view ever obtained by an Earth -based telescope, one can see frosty white water ice clouds, swirling orange dust storms above a rusty landscape, and various surface features, showing Mars to be a dynamic planet. The resolution in the original image was down to 16 km (10 miles). The colors have been balanced to give a realistic view of Mars' colors. There is a large amount of seasonal dust storm activity in this image. One large storm is above the northern polar cap (top of the image) and a smaller dust storm is seen nearby. Yet another large storm is emerging from the Hellas impact basin in the Southern Hemisphere (lower right). Mars and Earth opposition distances range from 56-101 million km (35-63 million miles). The 2001 opposition was the closest Mars had been to Earth since 1988. In 2003, Mars and Earth will come within 56 million km (35 million miles), which will be the closest Mars will be since 1924, and the closest it will be until 2287. Hubble Heritage Picture - August 2001 August's Hubble Heritage image is of ESO 510-G13, an edge-on spiral galaxy. 150 million light-years from us, ESO 510-G13 lies in the constellation Hydra; this image covers approximately 2.4 arcminutes across (105,000 light-years). The image was originally taken on April 6/7, 2001, for a total exposure time of 3.3 hours. This galaxy, first seen by the European Southern Observatory (ESO), is not a normal-looking spiral galaxy. Most spiral galaxies, such as our own Milky Way, appear relatively flat when viewed edge-on as in this image. However, ESO 510-G13 is very warped. This affords astronomers an opportunity to learn about how colliding galaxies spawn new generations of stars. Fortuitously, the bright light of the galaxy's core allows dust lanes and internal structure to be visible. The warping of the disk indicates that ESO 510-G13 recently collided with a nearby galaxy and it is in the process of consuming it. Eventually, the distortions will die out and the galaxy will return to a flat state. In portions of the outer regions of the galaxy, especially towards the right of the image, the disk contains bright clouds of blue stars. This shows that hot, young stars are being formed in the disk. Astronomers believe that the formation of the new stars is probably triggered by collisions between galaxies results from their interstellar clouds smashing together and compressing. Hubble Heritage Picture - September 2001
Most galaxies churn out stars at a fairly slow rate. A few galaxies, known as "starburst" galaxies, create stars much more quickly. NGC 3310, this month's Hubble Heritage image, is one of those. Scientists studying this galaxy are using it to help perfect a technique for determining the history of such galaxies by analyzing the colors of star clusters within the galaxy. Since younger stars are bluer and older ones redder, the color offers an estimate of the age. This galaxy has several hundred star cluster, seen as bright blue blotches throughout the spiral arms. With each cluster containing up to several million stars and taking less than 100,000 years to form, the rate of star formation in NGC 3310 is enormous. The cluster ages in this galaxy range up to a few hundred million years, indicating that the starburst "turned on" over 100 million years ago. This could have been triggered by a collision with a companion galaxy. This might change astronomers' theories of starburst galaxies, for the starburst episode was thought to be brief. However, the wide range of ages offered by this galaxy's clusters suggests otherwise. Hubble Heritage Picture - October 2001 October's Hubble Heritage image is of NGC 5139, AKA Omega Centauri, a globular cluster. 17,000 light-years from us, Omega Centauri lies in the constellation Centaurus; this image covers approximately 2.7 arcminutes down (13 light-years); this is only the core of the cluster, which has a total diameter of 450 light-years. The image was originally taken on June 11, 1997, for a total exposure time of 3 hours. Omega Centauri is one of the densest and most populated globular clusters that are known. At several million stars, ground-based telescopes are unable to resolve individual stars. Hubble, with its vantage point above Earth's turbulent atmosphere, allows astronomers to be able to see these as individual stars. Within this small window of 13 light-years tall, there are about 50,000 stars visible. For comparison, a similar cube centered on the sun would contain only about 6 stars. Most stars in this image are about the mass and temperature of the sun, making them yellow. A few red and blue stars, in other phases of stellar evolution, are visible, too. This cluster is about 12 billion years old; any sun-like stars that were born with the cluster would have already died by now, and they are too faint to see. One of the main uses for images such as this is to help scientists understand mechanisms for star capture and after-birth binary star formation. In the dense core of Omega Centauri, stars sometimes pass close enough to each other to be captured, in which case they would go into orbit about a common center of gravity. Two such pairs have been found in this image. One of the most luminous and massive globular clusters in our galaxy, it is also one of the few that is visible to the naked eye. Johann Bayer named the cluster in 1603 as the 24th -brightest object in the constellation Centaurus. It resembles a small cloud that could be mistaken for a comet. Hubble Heritage Picture - November 2001
In visible light, this galaxy shows the obvious characteristics of a barred spiral galaxy. However, when viewed in ultra-violet (UV) light (blue in this image), a ring of stars pops into view. This ring of stars helps to mark the vague outline of the central bar of this galaxy. The UV light is emitted from these hot, young stars more intensely than visible light. Some blue stars are also seen along the outer two dim spiral arms. The stars emitting in UV are young and very hot. Astronomers are using this image and others like it to help understand the relationship between the star formation that is seen in the UV light and how the bars might help localize the star formation into a ring shape. Hubble Heritage Picture - December 2001 December's Hubble Heritage image is of Hubble-V in NGC 6822, a gas cloud in the galaxy NGC 6822. 1.63 million light-years from us, Hubble-V lies in the constellation Sagittarius; this image covers approximately 25 arcseconds across (200 light-years). The image was originally taken on June 18, 1996, and August 2, 1997, for a total exposure time of 3.4 hours. This nebula offers astronomers a chance to see what star formation probably looked like in the early universe. The young, 4-million-years-old stars sitting in the heart of this nebula shine 100,000 times as brightly as the sun. They are too closely packed and far away to be resolvable by ground-based telescopes, but the sharp resolution of Hubble clearly separates them. The host galaxy to this nebula, NGC 6822, is one of the Milky Way's closest neighbors, and it is considered to be typically of the earliest fragments of galaxies that were in the early universe. 
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January's
Hubble Heritage image is of Hubble-X in NGC 6822, an H II region in the galaxy
NGC 6822. 1.63 million 
March's
Hubble Heritage image is of NGC 4013, an edge-on spiral galaxy
May's
Hubble Heritage image is of Barnard 33, AKA the Horsehead Nebula, a 
July's
Hubble Heritage image is of 
September's
Hubble Heritage image is of NGC 3310, a starburst galaxy. 59 million light-years
from us, NGC 3310 lies in the constellation Ursa Major; the galaxy has a
diameter of 52,000 light-years.The image was originally taken on March 13,
1997, and September 12/13, 2000, for a total exposure time of 52 minutes.
November's
Hubble Heritage image is of NGC 6782, a barred Spiral Galaxy. 183 million
light-years from us, NGC 6782lies in the constellation Pavo; this image covers
approximately 100 arcseconds across (82,000 light-years). The image was originally
taken on June 22, 2000, and June 9, 2001, for a total exposure time of 1.3
hours.