NGC 300 (also known as Baldwell 70 or the Sculptor Pinwheel Galaxy) is a spiral galaxy in the constellation Sculptor. It was discovered on 5 August 1826 by Scottish astronomer James Dunlop. It is one of the closest galaxies to the Local Group, and it most likely lies between the latter and the Sculptor Group. It is the brightest of the five main spirals in the direction of the Sculptor Group. It is inclined at an angle of 42° when viewed from Earth and shares many characteristics of the Triangulum Galaxy. It is 94,000 light-years in diameter, somewhat smaller than the Milky Way, and has an estimated mass of (2.9 ± 0.2) × 1010M☉.
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.
SN 2005df was a Type Ia supernova in the barred spiral galaxy NGC 1559, which is located in the southern constellation of Reticulum. The event was discovered in Australia by Robert Evans on the early morning of August 5, 2005 with a 13.8 magnitude, and was confirmed by A. Gilmore on August 6. The supernova was classified as Type Ia by M. Salvo and associates. It was positioned at an offset of 15.0″ east and 40.0″ north of the galaxy's nucleus, reaching a maximum brightness of 12.3 on August 18. The supernova luminosity appeared unreddened by dust from its host galaxy.
The Katzman Automatic Imaging Telescope (KAIT) is an automated telescope used in the search for supernovae.
NGC 2997 is a face-on unbarred spiral galaxy about 40 million light-years away in the faint southern constellation of Antlia. It was discovered March 4, 1793 by German-born astronomer William Herschel. J. L. E. Dreyer described it as, "a remarkable object, very faint, very large, very gradually then very suddenly bright middle and 4 arcsec nucleus. This is the brightest galaxy of the NGC 2997 group of galaxies, and was featured on the cover of the first edition of Galactic Dynamics by James Binney and Scott Tremaine.
NGC 2207 and IC 2163 are a pair of colliding spiral galaxies about 80 million light-years away in the constellation Canis Major. Both galaxies were discovered by John Herschel in 1835.
Type Ib and Type Ic supernovae are categories of supernovae that are caused by the stellar core collapse of massive stars. These stars have shed or been stripped of their outer envelope of hydrogen, and, when compared to the spectrum of Type Ia supernovae, they lack the absorption line of silicon. Compared to Type Ib, Type Ic supernovae are hypothesized to have lost more of their initial envelope, including most of their helium. The two types are usually referred to as stripped core-collapse supernovae.
SN 1993J is a supernova observed in Bode's Galaxy. It was discovered on 28 March 1993 by F. Garcia in Spain. At the time, it was the second-brightest type II supernova observed in the twentieth century behind SN 1987A, peaking at a visible apparent magnitude of 10.7 on March 30, with a second peak of 10.86 on April 18.
SN 2004GT was a type Ic supernova that happened in the interacting galaxy NGC 4038 on December 12, 2004. The event occurred in a region of condensed matter in the western spiral arm. The progenitor was not identified from older images of the galaxy, and is either a type WC Wolf-Rayet star with a mass over 40 times that of the Sun, or a star 20 to 40 times as massive as the Sun in a binary star system.
SN 2007uy was a supernova that occurred in the spiral galaxy NGC 2770. It was discovered by Yoji Hirose on December 31, 2007 from Chigasaki city in Japan, approximately four days after the explosion. The position of the supernova was offset 20.6″ east and 15.5″ south of the galaxy's nucleus, near a star-forming region. It was identified as a Type Ib supernova from its spectrum a week before reaching maximum, and appeared the most similar to SN 2004gq.
SN 2008ax was a helium-rich type Ib core-collapse supernova in the interacting galaxy NGC 4490. It was independently discovered on 3 March 2008 by LOSS and 4 March by Koichi Itagaki. The site had been monitored six hours before discovery, thus constraining the time of the explosion breakout. It was the third-brightest supernova of 2008. The brightness in the B-band peaked about 20 days after the explosion. X-ray emissions were detected from the event, which are most likely the result of shock heating from the supernova ejecta and circumstellar material.
NGC 7424 is a barred spiral galaxy located 37.5 million light-years away in the southern constellation Grus. Its size makes it similar to our own galaxy, the Milky Way. It is called a "grand design" galaxy because of its well defined spiral arms. Two supernovae and two ultraluminous X-ray sources have been discovered in NGC 7424.
SN 1994I is a Type Ic supernova discovered on April 2, 1994 in the Whirlpool Galaxy by amateur astronomers Tim Puckett and Jerry Armstrong of the Atlanta Astronomy Club. Type Ic supernova are a rare type of supernova that result from the explosion of a very massive star that has shed its outer layers of hydrogen and helium. The explosion results in a highly luminous burst of radiation that then dims over the course of weeks or months. SN 1994I was a relatively nearby supernova, and provided an important addition to the then small collection of known Type Ic supernova. Very early images were captured of SN 1994I, as two high school students in Oil City, Pennsylvania serendipitously took images of the Whirlpool Galaxy using the 30-inch telescope at Leuschner Observatory on March 31, 1994, which included SN 1994I just after it began to brighten.
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.
SN 1998aq is a nearby supernova located in the intermediate spiral galaxy NGC 3982, offset 18″ west and 7″ of the galactic nucleus. It was discovered April 13, 1998 by amateur astronomer Mark Armstrong and was confirmed by fellow British amateur Ron Arbour; both members of the U.K. Supernova/Nova Patrol. The event was not visible on a prior check by Armstrong made April 7. It reached peak brightness on April 27, and 15 days later had declined by 1.14 magnitudes in the B (blue) band.
NGC 613 is a barred spiral galaxy located 67 million light years away in the southern constellation of Sculptor. This galaxy was discovered in 1798 by German-English astronomer William Herschel, then re-discovered and catalogued by Scottish astronomer James Dunlop. It was first photographed in 1912, which revealed the spiral form of the nebula. During the twentieth century, radio telescope observations showed that a linear feature in the nucleus was a relatively strong source of radio emission.
NGC 4178 is the New General Catalogue identifier for a barred spiral galaxy in the equatorial constellation of Virgo. It was discovered April 11, 1825 by English astronomer John Herschel. Located some 43.8 million light years away, this galaxy spans 2.3 × 0.4 arc minutes and is seen at a low angle, being inclined by 77° to the line of sight from the Earth. The morphological classification of NGC 4178 is SB(rs)dm, indicating that it has a bar feature at the core, and, per the '(rs)', has traces of a ring-like structure surrounding the bar. The 'dm' suffix indicates the spiral arms are diffuse, broken, and irregular in appearance with no bulge at the nucleus. This galaxy is a member of the Virgo Cluster, which is the richest nearby group of galaxies outside the Local Group and forms the core of the Virgo Supercluster.
NGC 266 is a massive barred spiral galaxy in the constellation Pisces. NGC 266 is located at a distance of 197 megalight-years from the Milky Way. It was discovered on September 12, 1784, by William Herschel. The form of this barred galaxy is described by its morphological classification of SB(rs)ab, which indicates a quasi-ring-like structure (rs) and moderate-to-tightly wound spiral arms (ab). It is the dominant member of a small group with six low-mass galaxies.
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.
NGC 4589 is an elliptical galaxy located in the Draco constellation. It was discovered by German-British astronomer William Herschel on November 22, 1797. This galaxy lies at a distance of 73.0 million light-years (22.39 Mpc) from the Milky Way, and is receding with a heliocentric radial velocity of 2,002 km/s. It is known by its designations PGC 42139 or UGC 7797.
