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Astronomy Reference Libraries

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Sunflower Galaxy M63
2004-10-19 04:45:40

Sunflower Galaxy (M63) -- Discovered 1779 by Pierre Mchain. M63 was the very first discovery of a Deep Sky object by Messier's friend, Pierre Mchain, who caught it up on June 14, 1779. On the same day, Charles Messier included it in his catalog. The Sunflower galaxy M63 is one of the early recognized spiral galaxies, listed by Lord Rosse as one of 14 "spiral nebulae" discovered to 1850....

Sombrero Galaxy
2004-10-19 04:45:40

Sombrero Galaxy -- Discovered by Pierre Mchain or Charles Messier in 1781. M104 is numerically the first object of the catalog which was not included in Messier's originally published catalog. However, Charles Messier added it by hand to his personal copy on May 11, 1781, and described it as a "very faint nebula." It was Camille Flammarion who found that its position coincided with...

2004-10-19 04:45:40

Sirius -- Sirius (α Canis Major, also known as the Dog Star) is the brightest star (-1.46m) in the night sky and can be seen from every inhabited region of the Earth's surface. At a distance of 8.6 light years, Sirius is also one of the nearest stars to Earth. It is a main sequence star of spectral type A0 or A1 and has a mass about 2.4 times that of the Sun. Sirius has a white dwarf...

Seyferts Sextet
2004-10-19 04:45:40

Seyfert's Sextet -- Seyfert's Sextet is a group of galaxies in which gravitational forces are exerted between its members. The galaxies are so tightly packed together that gravitational forces are beginning to rip stars from them and distort their shapes. Those same gravitational forces eventually could bring the galaxies together to form one large galaxy. The name of this grouping,...

Saturn Nebula
2004-10-19 04:45:40

Saturn Nebula -- The layers of the Saturn Nebula give a complex picture of how this planetary nebula was created. The above picture, taken in April 1996 and released last week, allows a better understanding of the mysterious process that transformed a low-mass star into a white dwarf star. A computer model indicates that the central star of NGC 7009 first expelled the green gas that now...

Rosette Nebula
2004-10-19 04:45:40

Rosette Nebula -- Discovered by John Flamsteed about 1690. The Rosetta Nebula is a vast cloud of dust and gas, extending over an area of more than 1 degree across, or about 5 times the area covered by the full moon. Its parts have been assigned different NGC numbers: 2237, 2238, 2239, and 2246. Within the nebula, open star cluster NGC 2244 is situated, consisted of the young stars which...

Ring Nebula
2004-10-19 04:45:40

Ring Nebula -- Discovered by Antoine Darquier de Pellepoix in 1779. The famous ring nebula M57 is often regarded as the prototype of a planetary nebula, and a showpiece in the northern hemisphere summer sky. Recent research has confirmed that it is, most probably, actually a ring (torus) of bright light-emitting material surrounding its central star, and not a spherical (or ellipsoidal)...

Ptolemy Cluster
2004-10-19 04:45:40

Ptolemy Cluster -- Known to Ptolemy 130 AD. "M7 is a large and brilliant group, easily detected with the naked eye... the cluster is seen projected on a background of numerous faint and distant Milky Way stars." (Burnham). This splendid cluster was known to Ptolemy, who mentioned it about 130 AD, who described it as the "nebula following the sting of Scorpius". The description may...

Crab Nebula
2004-10-19 04:45:40

Crab Nebula -- The Crab Nebula (Messier 1, NGC 1952) is the object the which started Charles Messier logging non-cometary objects on his Messier Catalog. It is the expanding cloud of gas thrown off in the explosion that gave rise to the 1054 supernova recorded by Chinese astronomers, now more than 6 light years across (the nebula is currently expanding at 1000 km/sec and the total mass of...

Subaru Telescope
2004-10-19 04:45:40

Image Caption: The Subaru Telescope at the Mauna Kea Observatory on Hawaii. Credit: Denys/Wikipedia (CC BY-SA 3.0) The Subaru Telescope is a 26.9-foot (8.2m) telescope located at the Mauna Kea Observatory on the Big Island of Hawaii and operated by the National Astronomical Observatory of Japan (NAOJ). It had the largest primary mirror in the world until 2005. This is a reflecting...