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.
NGC 4631 is a barred spiral galaxy in the constellation Canes Venatici. This galaxy's slightly distorted wedge shape gives it the appearance of a herring or a whale, hence its nickname. Because this nearby galaxy is seen edge-on from Earth, professional astronomers observe this galaxy to better understand the gas and stars located outside the plane of the galaxy.
The Whirlpool Galaxy, also known as Messier 51a (M51a) or NGC 5194, is an interacting grand-design spiral galaxy with a Seyfert 2 active galactic nucleus. It lies in the constellation Canes Venatici, and was the first galaxy to be classified as a spiral galaxy. It is between 23 and 31 million light-years away and 76,900 ly (23,580 pc) in diameter.
NGC 5195 is a dwarf galaxy that is interacting with the Whirlpool Galaxy. Both galaxies are located approximately 25 million light-years away in the constellation Canes Venatici. Together, the two galaxies are one of the most famous interacting galaxy pairs.
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 2976 is a peculiar dwarf galaxy in the northern circumpolar constellation of Ursa Major. It was discovered by German-born astronomer William Herschel on November 8, 1801, and catalogued as H I.285. J. L. E. Dreyer described it as, "bright, very large, much extended 152°, star involved". It is a member of the M81 Group and lies 1° 20′ to the southwest of Messier 81. The projected separation of this galaxy from the M81 Group is 190 kpc.
NGC 4027 is a barred spiral galaxy approximately 83 million light-years away in the constellation Corvus. It is also a peculiar galaxy because one of its spiral arms goes out more than the other. This is probably due to a galactic collision in NGC 4027's past.
NGC 5033 is an inclined spiral galaxy located in the constellation Canes Venatici. Distance estimates vary from between 38 and 60 million light years from the Milky Way. The galaxy has a very bright nucleus and a relatively faint disk. Significant warping is visible in the southern half of the disk. The galaxy's relatively large angular size and relatively high surface brightness make it an object that can be viewed and imaged by amateur astronomers. The galaxy's location relatively near Earth and its active galactic nucleus make it a commonly studied object for professional astronomers.
NGC 5713 is a peculiar, asymmetric galaxy in the constellation Virgo. Although classified as a spiral galaxy by most galaxy catalogs, NGC 5713 is very different from most normal spiral galaxies. While most spiral galaxies either have either two well-defined spiral arms or a filamentary spiral-like structure, this spiral galaxy has only one visible spiral arm in its disk. This makes it a galaxy of the Magellanic type. Gravitational interactions with the nearby spiral galaxy NGC 5719 may be responsible for producing the disturbed, asymmetric structure including the single spiral arm.
NGC 5005, also known as Caldwell 29, is an inclined spiral galaxy in the constellation Canes Venatici. The galaxy has a relatively bright nucleus and a bright disk that contains multiple dust lanes. The galaxy's high surface brightness makes it an object that is visible to amateur astronomers using large amateur telescopes.
NGC 5474 is a peculiar dwarf galaxy in the constellation Ursa Major. It is one of several companion galaxies of the Pinwheel Galaxy (M101), a grand-design spiral galaxy. Among the Pinwheel Galaxy's companions, this galaxy is the closest to the Pinwheel Galaxy itself. The gravitational interaction between NGC 5474 and the Pinwheel Galaxy has strongly distorted the former. As a result, the disk is offset relative to the nucleus. The star formation in this galaxy is also offset from the nucleus. NGC 5474 shows some signs of a spiral structure. As a result, this galaxy is often classified as a dwarf spiral galaxy, a relatively rare group of dwarf galaxies.
NGC 4625 is a distorted dwarf galaxy in the constellation Canes Venatici. The galaxy is formally classified as a Sm galaxy, which means that its structure vaguely resembles the structure of spiral galaxies. The galaxy is sometimes referred to as a Magellanic spiral because of its resemblance to the Magellanic clouds.
Arp 240 is a pair of interacting spiral galaxies located in the constellation Virgo. The two galaxies are listed together as Arp 240 in the Atlas of Peculiar Galaxies. The galaxy on the right is known as NGC 5257, while the galaxy on the left is known as NGC 5258. Both galaxies are distorted by the gravitational interaction, and both are connected by a tidal bridge, as can be seen in images of these galaxies.
The H I Parkes All Sky Survey (HIPASS) is a large survey for neutral atomic hydrogen (H I). Most of the data was taken between 1997 and 2002 using CSIRO's 64 m Parkes Telescope. HIPASS covered 71% of the sky and identified more than 5000 galaxies; the major galaxy catalogs are: the "HIPASS Bright Galaxy Catalog", the southern HIPASS catalog (HICAT), and the northern HIPASS catalog (NHICAT) Discoveries include over 5000 galaxies, the Leading Arm of the Magellanic Stream and a few gas clouds devoid of stars.
NGC 3169 is a spiral galaxy about 75 million light years away in the constellation Sextans. It has the morphological classification SA(s)a pec, which indicates this is a pure, unbarred spiral galaxy with tightly-wound arms and peculiar features. There is an asymmetrical spiral arm and an extended halo around the galaxy. It is a member of the NGC 3166 Group of galaxies, which 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.
NGC 925 is a barred spiral galaxy located about 30 million light-years away in the constellation Triangulum. The morphological classification of this galaxy is SB(s)d, indicating that it has a bar structure and loosely wound spiral arms with no ring. The spiral arm to the south is stronger than the northern arm, with the latter appearing flocculent and less coherent. The bar is offset from the center of the galaxy and is the site of star formation all along its length. Both of these morphological traits—a dominant spiral arm and the offset bar—are typically characteristics of a Magellanic spiral galaxy. The galaxy is inclined at an angle of 55° to the line of sight along a position angle of 102°.
Magellanic spiral galaxies are (usually) dwarf galaxies which are classified as the type Sm. They are galaxies with one single spiral arm, and are named after their prototype, the Large Magellanic Cloud, an SBm galaxy. They can be considered to be intermediate between dwarf spiral galaxies and irregular galaxies.
NGC 4651 is a spiral galaxy located in the constellation of Coma Berenices that can be seen with amateur telescopes, at a distance not well determined that ranges from 35 million light years to 72 million light years.
NGC 1614 is the New General Catalogue identifier for a spiral galaxy in the equatorial constellation of Eridanus. It was discovered on December 29, 1885 by American astronomer Lewis Swift, who described it in a shorthand notation as: pretty faint, small, round, a little brighter middle. The nebula was then catalogued by Danish-Irish astronomer J. L. E. Drayer in 1888. When direct photography became available, it was noted that this galaxy displayed some conspicuous peculiarities. American astronomer Halton Arp included it in his 1966 Atlas of Peculiar Galaxies. In 1971, Swiss astronomer Fritz Zwicky described it as a "blue post-eruptive galaxy, compact patchy core, spiral plumes, long blue jet SSW".
NGC 4731 is a barred spiral galaxy located near the Virgo supercluster. To its celestial south lies NGC 4731A, a small irregular galaxy. Both galaxies feature high concentrations of neutral HI gas. It is theorized that its elongated arm structure could be related to gravitational interactions with a nearby galaxy, NGC 4967. It is a member of the NGC 4697 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.
