Canes Venatici is one of the 88 constellations designated by the International Astronomical Union (IAU). It is a small northern constellation that was created by Johannes Hevelius in the 17th century. Its name is Latin for 'hunting dogs', and the constellation is often depicted in illustrations as representing the dogs of Boötes the Herdsman, a neighboring constellation.
The New General Catalogue of Nebulae and Clusters of Stars is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and emission nebulae. Dreyer published two supplements to the NGC in 1895 and 1908, known as the Index Catalogues, describing a further 5,386 astronomical objects. Thousands of these objects are best known by their NGC or IC numbers, which remain in widespread use.
The Helix Nebula is a planetary nebula (PN) located in the constellation Aquarius. Discovered by Karl Ludwig Harding, most likely before 1824, this object is one of the closest of all the bright planetary nebulae to Earth. The distance, measured by the Gaia mission, is 655±13 light-years. It is similar in appearance to the Cat's Eye Nebula and the Ring Nebula, whose size, age, and physical characteristics are similar to the Dumbbell Nebula, varying only in its relative proximity and the appearance from the equatorial viewing angle. The Helix Nebula has sometimes been referred to as the "Eye of God" in pop culture, as well as the "Eye of Sauron".
NGC 4631 is a barred spiral galaxy in the constellation Canes Venatici about 30 million light years away from Earth. 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.
Messier 59 or M59, also known as NGC 4621, is an elliptical galaxy in the equatorial constellation of Virgo. It is a member of the Virgo Cluster, with the nearest fellow member 8′ away and around 5 magnitudes fainter. The nearest cluster member of comparable brightness is the lenticular galaxy NGC 4638, which is around 17′ away. It and the angularly nearby elliptical galaxy Messier 60 were both discovered by Johann Gottfried Koehler in April 1779 when observing comet seeming close by. Charles Messier listed both in the Messier Catalogue about three days after Koehler's discovery.
NGC 2419 is a globular cluster in the constellation Lynx. It was discovered by William Herschel on December 31, 1788. NGC 2419 is at a distance of about 300,000 light years from the Solar System and at the same distance from the Galactic Center.
NGC 1818 is a young globular cluster in the north-west part of the Large Magellanic Cloud, about 3.2 kpc from the center. It was discovered by Scottish astronomer James Dunlop in 1826, and has since been well studied.
NGC 7319 is a highly distorted barred spiral galaxy that is a member of the compact Stephan's Quintet group located in the constellation Pegasus, some 311 megalight-years distant from the Milky Way. The galaxy's arms, dust and gas have been highly disturbed as a result of the interaction with the other members of the Quintet. Nearly all of the neutral hydrogen has been stripped from this galaxy, most likely as a result of a collision with NGC 7320c some 100 million years ago. A pair of long, parallel tidal tails extend southward from NGC 7319 in the direction of NGC 7320c, and is undergoing star formation.
The Collinder catalogue is a catalogue of 471 open clusters compiled by Swedish astronomer Per Collinder. It was published in 1931 as an appendix to Collinder's paper On structural properties of open galactic clusters and their spatial distribution.
NGC 3281 is a large unbarred spiral galaxy in the southern constellation of Antlia, located at a distance of 144.7 megalight-years from the Milky Way. The galaxy is inclined by an angle of 64° to the line-of-sight from the Earth, with the major axis aligned with a position angle of 137°. It is a luminous infrared galaxy and a type II Seyfert galaxy. NGC 3281 is a member of the Antlia Cluster, which belongs to the Hydra–Centaurus Supercluster.
NGC 6642 is a globular cluster located 26,700 light-years from Earth, in the constellation Sagittarius. Many "blue stragglers" have been spotted in this globular, and it is known to be lacking in low-mass stars.
NGC 54 is an edge-on spiral galaxy in the constellation of Cetus. The galaxy was discovered by Wilhelm Tempel in 1886, and he defined it as "very faint, pretty small, round." The galaxy is 90,000 light years in diameter, making it slightly smaller than the Milky Way.
NGC 210 is a barred spiral galaxy located roughly 67 million light-years from the Solar System in the constellation Cetus. It was discovered on October 3, 1785 by William Herschel and later added to the New General Catalogue.
NGC 68 is a lenticular galaxy, and the central member of the NGC 68 group, in the constellation Andromeda. The galaxy was discovered on September 11, 1784, by William Herschel, who observed the NGC 68 group as a single object and described it as "extremely faint, large, 3 or 4 stars plus nebulosity". As such, his reported location is between NGC 68, NGC 70, and NGC 71. By the time Dreyer looked at the galaxies to add to the NGC catalog, however, he was able to tell that the single galaxy observed by Herschel was in fact 3 adjacent galaxies, and cataloged them as NGC 68, NGC 70, and NGC 71.
NGC 5643 is an intermediate spiral galaxy in the constellation Lupus. Based on the tip of the red-giant branch distance indicator, it is located at a distance of about 40 million light-years. NGC 5643 has an active galactic nucleus and is a type II Seyfert galaxy.
NGC 6940 is an open cluster in the constellation Vulpecula. It was discovered by William Herschel in 1784. The cluster is nearly a billion years old and it is located 2,500 light years away. It is considered the finest open cluster in the constellation.
NGC 4298 is a flocculent spiral galaxy located about 53 million light-years away in the constellation Coma Berenices. The galaxy was discovered by astronomer William Herschel on April 8, 1784 and is a member of the Virgo Cluster.
NGC 4302 is an edge-on spiral galaxy located about 55 million light-years away in the constellation Coma Berenices. It was discovered by astronomer William Herschel on April 8, 1784 and is a member of the Virgo Cluster.
NGC 2950 is a lenticular galaxy in the northern constellation of Ursa Major, about 50 million light years from the Milky Way and receding with a heliocentric radial velocity of 1,329 km/s. It was discovered in 1790 by the Anglo-German astronomer William Herschel. NGC 2950 is a field galaxy, it is not part of a galaxy cluster or galaxy group, and thus is gravitationally isolated. Nine certain and four possible dwarf galaxies have been identified around NGC 2950.
