Messier 61 is an intermediate barred spiral galaxy in the Virgo Cluster of galaxies. It was first discovered by Barnaba Oriani on May 5, 1779, six days before Charles Messier discovered the same galaxy. Messier had observed it on the same night as Oriani but had mistaken it for a comet. Its distance has been estimated to be 45.61 million light years from the Milky Way Galaxy. It is a member of the M61 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.
Messier 81 (also known as NGC 3031 or Bode's Galaxy) is a grand design spiral galaxy about 12 million light-years away in the constellation Ursa Major. It has a D25 isophotal diameter of 29.44 kiloparsecs (96,000 light-years). Because of its relative proximity to the Milky Way galaxy, large size, and active galactic nucleus (which harbors a 70 million M☉ supermassive black hole), Messier 81 has been studied extensively by professional astronomers. The galaxy's large size and relatively high brightness also makes it a popular target for amateur astronomers. In late February 2022, astronomers reported that M81 may be the source of FRB 20200120E, a repeating fast radio burst.
Messier 66 or M66, also known as NGC 3627, is an intermediate spiral galaxy in the southern, equatorial half of Leo. It was discovered by French astronomer Charles Messier on 1 March 1780, who described it as "very long and very faint". This galaxy is a member of a small group of galaxies that includes M65 and NGC 3628, known as the Leo Triplet or the M66 Group. M65 and M66 are a common object for amateur astronomic observation, being separated by only 20′.
Messier 74 is a large spiral galaxy in the equatorial constellation Pisces. It is about 32 million light-years away from Earth. The galaxy contains two clearly defined spiral arms and is therefore used as an archetypal example of a grand design spiral galaxy. The galaxy's low surface brightness makes it the most difficult Messier object for amateur astronomers to observe. Its relatively large angular size and the galaxy's face-on orientation make it an ideal object for professional astronomers who want to study spiral arm structure and spiral density waves. It is estimated that M74 hosts about 100 billion stars.
NGC 2403 is an intermediate spiral galaxy in the constellation Camelopardalis. It is an outlying member of the M81 Group, and is approximately 8 million light-years distant. It bears a similarity to M33, being about 50,000 light years in diameter and containing numerous star-forming H II regions. The northern spiral arm connects it to the star forming region NGC 2404. NGC 2403 can be observed using 10×50 binoculars. NGC 2404 is 940 light-years in diameter, making it one of the largest known H II regions. This H II region represents striking similarity with NGC 604 in M33, both in size and location in galaxy.
NGC 3982(also known as UGC 6918) is an intermediate spiral galaxy approximately 68 million light-years away in the constellation Ursa Major. It was discovered by William Herschel on April 14, 1789, and misclassified as a planetary nebula. NGC 3982 is a part of the M109 Group.
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 4414, also known as the Dusty Spiral Galaxy, is an unbarred spiral galaxy about 62 million light-years away in the constellation Coma Berenices. It was discovered by German-British astronomer William Herschel on 13 March 1785.
The Katzman Automatic Imaging Telescope (KAIT) is an automated telescope used in the search for supernovae.
NGC 1637 is an isolated, non-interacting intermediate spiral galaxy in the constellation Eridanus, about a degree to the WNW of the star Mu Eridani. It was discovered by German-British astronomer William Herschel on 1 February 1786. It is located at a distance of about 9.77 ± 1.82 Mpc (31.9 ± 5.9 Mly) from the Milky Way. The galaxy is inclined at an angle of 31.1° to the line of sight from the Earth and the long axis is oriented along a position angle of 16.3°.
NGC 7479 is a barred spiral galaxy about 105 million light-years away in the constellation Pegasus. William Herschel discovered it in 1784. NGC 7479 is also recognized as a Seyfert galaxy and a LINER undergoing starburst activity not only on the nucleus and the outer arms, but also across the bar of the galaxy, where most of the stars were formed in the last 100 million years. Polarization studies of this galaxy indicate that it recently underwent a minor merger and that it is unique in the radio continuum, with arms opening in a direction opposite to the optical arms. This feature, along with the asymmetrical arms of the galaxy and the intense star formation activity are attributed to a merger with a smaller galaxy. This galaxy is similar in both size and morphology to the barred spiral NGC 1300.
NGC 6118 is a grand design spiral galaxy located 83 million light-years away in the constellation Serpens. It was discovered on 14 April 1785 by German-British astronomer William Herschel.
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 3621 is a field spiral galaxy about 22 Mly (6.7 Mpc) away in the equatorial constellation of Hydra. It was discovered by German-British astronomer William Herschel on 17 February 1790.
SN 2014J was a type-Ia supernova in Messier 82 discovered in mid-January 2014. It was the closest type-Ia supernova discovered for 42 years, and no subsequent supernova has been closer as of 2023. The supernova was discovered by chance during an undergraduate teaching session at the University of London Observatory. It peaked on 31 January 2014, reaching an apparent magnitude of 10.5. SN 2014J was the subject of an intense observing campaign by professional astronomers and was bright enough to be seen by amateur astronomers.
A type Iax supernova is a rare subtype of type Ia supernova, which leaves behind a remnant star, known as zombie star, rather than completely dispersing the white dwarf. Type Iax supernovae are similar to type Ia, but have a lower ejection velocity and lower luminosity. Type Iax supernovae may occur at a rate between 5 and 30 percent of the Ia supernova rate. As of October 2014, thirty supernovae had been identified in this category.
NGC 1084 is an unbarred spiral galaxy in the constellation Eridanus. It is located at a distance of about 63 million light-years away from the Milky Way. The galaxy was discovered by William Herschel on 10 January 1785. It has multiple spiral arms, which are not well defined. It belongs in the same galaxy group with NGC 988, NGC 991, NGC 1022, NGC 1035, NGC 1042, NGC 1047, NGC 1052 and NGC 1110. This group is in turn associated with the Messier 77 group.
NGC 4242 is a spiral galaxy in the northern constellation of Canes Venatici. The galaxy is about 18 million light years away. It was discovered on 10 April 1788 by William Herschel, and it was described as "very faint, considerably large, irregular, round, very gradually brighter in the middle, resolvable" by John Louis Emil Dreyer, the compiler of the New General Catalogue.
NGC 2336 is a barred spiral galaxy located in the constellation Camelopardalis. It is located at a distance of circa 100 million light years from Earth, which, given its apparent dimensions, means that NGC 2336 is about 200,000 light years across. It was discovered by Wilhelm Tempel in 1876.
IC 5145 is a type Sab spiral galaxy located in the constellation Pegasus. It is located 356 million light-years from the Solar System and was discovered by Edward Emerson Barnard, although the year he discovered it is unknown.
