 | |
| Event type | Supernova  |
|---|---|
| Type Ia [1] | |
| Date | April 26, 2011 (UTC) |
| Constellation | Ursa Major |
| Right ascension | 11h 55m 45.56s [2] |
| Declination | +55° 19′ 33.8″ [1] |
| Epoch | J2000 |
| Redshift | 0.003402 ±5e-06 |
| Host | NGC 3972 [1] |
| Peak apparent magnitude | < 12 [1] |
| Other designations | SN 2011by |
SN 2011by was a supernova in NGC 3972. It was a type Ia supernova, discovered by Zhangwei Jin and Xing Gao (China). SN 2011by is about 5.3" east and 19.1" north of the center of NGC 3972. [1] [2]
NGC 6946, sometimes referred to as the Fireworks Galaxy, is a face-on intermediate spiral galaxy with a small bright nucleus, whose location in the sky straddles the boundary between the northern constellations of Cepheus and Cygnus. Its distance from Earth is about 25.2 million light-years or 7.72 megaparsecs, similar to the distance of M101 in the constellation Ursa Major. Both were once considered to be part of the Local Group, but are now known to be among the dozen bright spiral galaxies near the Milky Way but beyond the confines of the Local Group. NGC 6946 lies within the Virgo Supercluster.
NGC 4088 is an intermediate spiral galaxy in the constellation Ursa Major. The galaxy forms a physical pair with NGC 4085, which is located 11′ away.
NGC 1032 is a spiral galaxy that is about 117 million light-years away in the constellation Cetus.
NGC 2770 is a spiral galaxy in the northern constellation of Lynx, near the northern constellation border with Cancer. It was discovered by German-born astronomer William Herschel on December 7, 1785. J. L. E. Dreyer described it as, "faint, large, much extended 150°, mottled but not resolved, 2 stars to north". NGC 2770 was the target for the first binocular image produced by the Large Binocular Telescope.
SN 2002bj was the explosion of a star in the galaxy NGC 1821, located in the constellation Lepus. The explosion was discovered by Jack Newton in scans of images produced by Tim Puckett. Initially it had an apparent magnitude of about 14.7 and was categorized as a Type IIn supernova. However, in 2008 Dovi Poznanski discovered that the spectrum more closely resembled a Type Ia supernova. Further, the energy output was much lower than a typical supernova and the luminosity dropped at a dramatic pace.
NGC 4666 is a spiral galaxy in the equatorial constellation of Virgo, located at a distance of approximately 55 megalight-years from the Milky Way. It was discovered by the German-born astronomer William Herschel on February 22, 1784. It is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster. John L. E. Dreyer described it as "bright, very large, much extended 45°±, pretty suddenly brighter middle". It is a member of an interacting system with NGC 4668 and a dwarf galaxy, and belongs to a small group that also includes NGC 4632.
NGC 474 is an elliptical galaxy about 100 million light years distant in the constellation Pisces. This large galaxy is known to possess tidal shells and tidal tails, although their origins remain unclear. One possible explanation is that NGC 474 interacted with a galaxy several billion years ago.
NGC 5584 is a barred spiral galaxy in the constellation Virgo. It was discovered July 27, 1881 by American astronomer E. E. Barnard. Distance determination using Cepheid variable measurements gives an estimate of 75 million light years, whereas the tip of the red-giant branch approach yields a distance of 73.4 million light years. It is receding with a heliocentric radial velocity of 1,637 km/s. It is a member of the Virgo III Groups, a series of galaxies and galaxy clusters strung out to the east of the Virgo Supercluster of galaxies.
NGC 3938 is an unbarred spiral galaxy in the Ursa Major constellation. It was discovered on 6 February 1788 by William Herschel. It is one of the brightest spiral galaxies in the Ursa Major South galaxy group and is roughly 67,000 light years in diameter. It is approximately 43 million light years away from Earth. NGC 3938 is classified as type Sc under the Hubble sequence, a loosely wound spiral galaxy with a smaller and dimmer bulge. The spiral arms of the galaxy contain many areas of ionized atomic hydrogen gas, more so towards the center.
NGC 4790 is a barred spiral galaxy located in the constellation of Virgo. It was discovered on 25 March 1786 by William Herschel and included in the New General Catalogue in 1888. It is a member of the NGC 4699 Group of galaxies, which is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster.
NGC 3198, also known as Herschel 146 is a barred spiral galaxy in the constellation Ursa Major. It was discovered by William Parsons, 3rd Earl of Rosse, sometime before 1850. NGC 3198 is located in the Leo Spur, which is part of the Virgo Supercluster, and is approximately 47 million light years away.
NGC 6925 is an unbarred spiral galaxy in the constellation Microscopium of apparent magnitude 11.3. It is lens-shaped, as it lies almost edge on to observers on Earth. It lies 3.7 degrees west-northwest of Alpha Microscopii.
NGC 4424 is a spiral galaxy located in the equatorial constellation of Virgo. It was discovered February 27, 1865 by German astronomer Heinrich Louis d'Arrest. This galaxy is located at a distance of 13.5 million light years and is receding with a heliocentric radial velocity of 442 km/s. It has a morphological class of SB(s)a, which normally indicates a spiral galaxy with a barred structure (SB), no inner ring feature (s), and tightly-wound spiral arms (a). The galactic plane is inclined at an angle of 62° to the line of sight from the Earth. It is a likely member of the Virgo Cluster of galaxies.
SN 2013ej is a Type II-P supernova in the nearby spiral galaxy Messier 74. It was discovered by the Lick Observatory Supernova Search on July 25, 2013, with the 0.76 m Katzman Automatic Imaging Telescope, with pre-discovery images having been taken the day before.
NGC 523, also known as Arp 158, from the ARP catalog is a spiral galaxy located in the constellation Andromeda. It was discovered separately by William Herschel on 13 September 1784, and by Heinrich d'Arrest on 13 August 1862. d'Arrest's discovery was listed as NGC 523, while Herschel's was listed as NGC 537; the two are one and the same. John Dreyer noted in the New General Catalogue that NGC 523 is a double nebula.
NGC 1964 is a barred spiral galaxy in the constellation Lepus. The galaxy lies 65 million light years away from Earth, which means, given its apparent dimensions, that NGC 1964 is approximately 100,000 light years across. At its center lies a supermassive black hole, with estimated mass 2.5 × 107M☉. The galaxy features two tightly wound inner spiral arms within a disk with high surface brightness and two outer, more open spiral arms that originate near the inner ring. The outer arms feature few small HII regions.
NGC 4699 is an intermediate spiral galaxy located in the constellation Virgo. It is located at a distance of circa 65 million light years from Earth, which, given its apparent dimensions, means that NGC 4699 is about 85,000 light years across. It was discovered by William Herschel in 1786. It is a member of the NGC 4699 Group of galaxies, which is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster.
NGC 3972 is a spiral galaxy located in the northern constellation of Ursa Major. It was discovered by William Herschel on April 14, 1789. This galaxy is located 66 million light years away and is receding with a heliocentric radial velocity of 846 km/s. It is a member of the NGC 3992 Group of galaxies.
NGC 819 is a spiral galaxy approximately 302 million light-years away from Earth in the constellation of Triangulum. It forms a visual pair with the galaxy NGC 816 5.7' WNW.
NGC 3294 is a spiral galaxy in the constellation Leo Minor. It was discovered by William Herschel on Mar 17, 1787. It is a member of the Leo II Groups, a series of galaxies and galaxy clusters strung out from the right edge of the Virgo Supercluster. The galaxy is located at a distance of 98 million light years and is receding with a heliocentric radial velocity of 1,586 km/s. The morphological class of NGC 3294 is SA(rs)bc, which means this is a spiral galaxy with no central bar (SA), an incomplete inner ring structure (rs), and moderately wound spiral arms (bc).
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