Hubble Space Telescope
"Orbiting the Earth since 1990, the Hubble Space Telescope has helped to answer some of the most compelling astronomical questions of our time, and uncovered mysteries we never knew existed. With vision that spans the ultraviolet through visible and into the near infrared, Hubble investigates everything from black holes to planets around other stars. Its unique capabilities are revolutionizing astronomy as Hubble continues humanity’s quest to explore the universe."(hubblesite.org)
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| NGC 7293 "This infrared image from NASA's Spitzer Space Telescope shows the Helix nebula, a cosmic starlet often photographed by amateur astronomers for its vivid colors and eerie resemblance to a giant eye. The nebula, located about 700 light-years away in the constellation Aquarius, belongs to a class of objects called planetary nebulae. Planetary nebulae are actually the remains of stars that once looked a lot like our sun. When sun-like stars die, they puff out their outer gaseous layers. These layers are heated by the hot core of the dead star, called a white dwarf, and shine with infrared and visible-light colors. Our own sun will blossom into a planetary nebula when it dies in about five billion years."(spitzer.caltech.edu)NASA |
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| The Cat's Eye Nebula or NGC 6543, is a relatively bright planetary nebula in the northern constellation of Draco, discovered by William Herschel on February 15, 1786. It was the first planetary nebula whose spectrum was investigated by the English amateur astronomer William Huggins, demonstrating that planetary nebulae were gaseous and not stellar in nature. Structurally, the object has had high-resolution images by the Hubble Space Telescope revealing knots, jets, bubbles and complex arcs, being illuminated by the central hot planetary nebula nucleus (PNN). It is a well-studied object that has been observed from radio to X-ray.Wikipedia ( Composite image using optical images from the HST and X-ray data from the Chandra X-ray Observatory ) |
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| The Horsehead Nebula (also known as Barnard 33) is a small dark nebula in the constellation Orion.The nebula is located just to the south of Alnitak, the easternmost star of Orion's Belt, and is part of the much larger Orion Molecular Cloud Complex. It appears within the southern region of the dense dust cloud known as Lynds 1630, along the edge of the much larger, active star-forming H II region called IC 434.The Horsehead Nebula is approximately 422 parsecs or 1375 light years from Earth.It is one of the most identifiable nebulae because of its resemblance to a horse's head.Wikipedia (The Horsehead Nebula. The reflection nebula NGC 2023 is in the bottom left corner and the nebula itself near the center, in the shape of the head of a horse. - Interstellar dust of the Horsehead Nebula as revealed by the Hubble Space Telescope.) |
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| NGC 7635, also known as the Bubble Nebula, Sharpless 162, or Caldwell 11, is an H II regionemission nebula in the constellation Cassiopeia. It lies close to the direction of the open cluster Messier 52. The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star, SAO 20575 (BD+60°2522). The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in 1787 by William Herschel. The star BD+60°2522 is thought to have a mass of about 44 M☉. |
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| The Cartwheel Galaxy (also known as ESO
350-40 or PGC 2248) is a lenticular galaxy and ring galaxy about 500
million light-years away in the constellation Sculptor. It is an
estimated 150,000 light-years diameter, and has a mass of about 2.9–4.8 ×
109 solar masses; its outer ring has a circular velocity of 217 km/s. It was discovered by Fritz Zwicky in 1941. Zwicky considered his discovery to be "one of the most complicated structures awaiting its explanation on the basis of stellar dynamics." An estimation of the galaxy's span resulted in a conclusion of 150,000 light years, which is slightly smaller than the Milky Way.Wikipedia |
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| Interacting peculiar galaxies. NGC 3808A
is the face-on spiral to the right. Material bridging the galaxies can
be seen and is evidence these two galaxies have passed close to each
other.Edge-on spiral is a background galaxy. This image was featured on APOD Dec 9, 2015 and the APOD page has been translated into a few languages.(remote-astrophotography.com) |
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| Stephan's Quintet is a visual grouping of five galaxies of which four form the first compact galaxy group ever discovered. The group, visible in the constellation Pegasus, was discovered by Édouard Stephan in 1877 at the Marseille Observatory.The group is the most studied of all the compact galaxy groups. The brightest member of the visual grouping is NGC 7320 that is shown to have extensive H II regions, identified as red blobs, where active star formation is occurring. Four of the five galaxies in Stephan's Quintet form a physical association, Hickson Compact Group 92, and will likely merge with each other. Radio observations in the early 1970s revealed a mysterious filament of emission which lies in inter-galactic space between the galaxies in the group. This same region is also detected in the faint glow of ionized atomic hydrogen seen in the visible part of the spectrum as a green arc. Wikipedia |
