The Triangulum Galaxy is a spiral galaxy 2.73 million light-years (ly) from Earth in the constellation Triangulum. It is catalogued as Messier 33 or NGC (New General Catalogue) 598. With the D25 isophotal diameter of 18.74 kiloparsecs (61,100 light-years), the Triangulum Galaxy is the third-largest member of the Local Group of galaxies, behind the Andromeda Galaxy and the Milky Way.
The Pinwheel Galaxy is a face-on spiral galaxy 21 million light-years away from Earth in the constellation Ursa Major. It was discovered by Pierre Méchain in 1781 and was communicated that year to Charles Messier, who verified its position for inclusion in the Messier Catalogue as one of its final entries.
Messier 83 or M83, also known as the Southern Pinwheel Galaxy and NGC 5236, is a barred spiral galaxy approximately 15 million light-years away in the constellation borders of Hydra and Centaurus. Nicolas-Louis de Lacaille discovered M83 on 23 February 1752 at the Cape of Good Hope. Charles Messier added it to his catalogue of nebulous objects in March 1781.
Eta Cassiopeiae is a binary star system in the northern constellation of Cassiopeia. Its binary nature was first discovered by William Herschel in August 1779. Based upon parallax measurements, the distance to this system is 19.42 light-years from the Sun. The two components are designated Eta Cassiopeiae A and B.
The M101 Group is a loose group of galaxies located in the constellation Ursa Major. The group is named after the brightest galaxy in the group, the Pinwheel Galaxy (M101). Most of the other members of the group are companions of the Pinwheel Galaxy. The group itself is one of many located within the Virgo Supercluster.
NGC 891 is an edge-on unbarred spiral galaxy about 30 million light-years away in the constellation Andromeda. It was discovered by William Herschel on October 6, 1784. The galaxy is a member of the NGC 1023 group of galaxies in the Local Supercluster. It has an H II nucleus.
Alpha Vulpeculae, officially named Anser, is the brightest star in the constellation of Vulpecula. It is approximately 291 light-years from Earth. It forms a wide optical binary with 8 Vulpeculae.
The NGC 5866 Group is a small group of galaxies located in the constellation Draco. The group is named after NGC 5866, the galaxy with the highest apparent magnitude in the group, although some galaxy group catalogs list NGC 5907 as the brightest member.
49 Cassiopeiae is a binary star system in the northern circumpolar constellation of Cassiopeia. It is visible to the naked eye as a faint, yellow-hued point of light with an apparent visual magnitude of 5.22. The system is located about 412 light years away from the Sun, based on parallax. The pair had an angular separation of 5.40″ along a position angle of 244°, as of 2008, with the brighter component being of magnitude 5.32 and its faint companion having magnitude 12.30.
6 Cassiopeiae is a white hypergiant in the constellation Cassiopeia, and a small-amplitude variable star.
LL Pegasi is a Mira variable star surrounded by a pinwheel-shaped nebula, IRAS 23166+1655, thought to be a preplanetary nebula. It is a binary system that includes an extreme carbon star. The pair is hidden by the dust cloud ejected from the carbon star and is only visible in infrared light.
53 Persei is a single variable star in the northern constellation of Perseus. It has the Bayer designation d Persei, while 53 Persei is the Flamsteed designation. The star is visible to the naked eye as a faint, blue-white hued point of light with an apparent visual magnitude of 4.80. It is located approximately 480 light years away from the Sun, as determined from parallax, and is drifting further away with a radial velocity of +7.3 km/s.
UGC 9796 is a lenticular and polar-ring galaxy in the constellation Boötes, and about 250 million light years distant from Earth. It is an object of great scientific interest as there have been very few polar ring galaxies discovered. UGC 9796 is a very gas-rich environment hosting as much 5×109 solar masses of neutral hydrogen. DSS and SDSS images show that it is very similar to polar ring galaxy NGC 660, the best-known of all the polar ring galaxies.
UGC 4879, which is also known as VV 124, is the most isolated dwarf galaxy in the periphery of the Local Group. It is an irregular galaxy at a distance of 1.38 Mpc. Low-resolution spectroscopy yielded inconsistent radial velocities for different components of the galaxy, hinting at the presence of a stellar disk. There is also evidence of this galaxy containing dark matter.
BV Centauri is a cataclysmic variable binary star in the constellation Centaurus. It is a dwarf nova, and undergoes rapid increases in brightness that are recurrent with a mean period of 150 days. This period seems to have increased in the last few decades. During quiescence, its visual apparent magnitude is about 13, with variations of a few tenths of magnitude over an orbit due to differences in the star's visible surface area, brightening to a maximum magnitude of 10.7 during outbursts. From its luminosity, it is estimated that the system is about 500 parsecs (1,600 ly) away from Earth. A Gaia parallax of 2.81 mas has been measured, corresponding to about 360 pc.
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.
UGC 9391 is a Magellanic spiral galaxy in constellation Draco. 130 million light years from Earth, it is not a member of any group of galaxies, and is moving away from the Earth at 1939 km/s.
HD 68375 is a solitary star in the northern circumpolar constellation Camelopardalis. It is faintly visible to the naked eye with an apparent magnitude of 5.54 and is estimated to be 289 light years distant. However, it is receding with a heliocentric radial velocity of 4.33 km/s.
