The Sculptor Constellation

Sculptor is a small and faint constellation in the southern sky. It represents a sculptor. It was introduced by Nicolas Louis de Lacaille in the 18th century. He originally named it Apparatus Sculptoris (the sculptor’s studio), but the name was later shortened. Sculptor is bordered by Aquarius and Cetus to the north, Fornax to the east, Phoenix to the south, Grus to the southwest, and Piscis Austrinus to the west. The official constellation boundaries, as set by Eugène Delporte in 1930, are defined by a polygon of 6 segments. In the equatorial coordinate system, the right ascension coordinates of these borders lie between  23h 06.4m and  01h 45.5m, while the declination coordinates are between −24.80° and −39.37°. The whole constellation is visible to observers south of latitude 50°N.

No stars brighter than 3rd magnitude are located in Sculptor. This is explained by the fact that Sculptor contains the south galactic pole where stellar density is very low. Overall, there are 56 stars within the constellation’s borders brighter than or equal to apparent magnitude 6.5. The brightest star is Alpha Sculptoris, an SX Arietis-type variable star with a spectral type B7IIIp and an apparent magnitude of 4.3. It is 780 ± 30 light-years distant from Earth. Eta Sculptoris is a red giant of spectral type M4III that varies between magnitudes 4.8 and 4.9, pulsating with multiple periods of 22.7, 23.5, 24.6, 47.3, 128.7 and 158.7 days. Estimated to be around 1,082 times as luminous as the Sun, it is 460 ± 20 light-years distant from Earth. R Sculptoris is a red giant that has been found to be surrounded by spirals of matter likely ejected around 1800 years ago. It is 1,440 ± 90 light-years distant from Earth.

The Sculptor Group is a group of galaxies located near the south galactic pole in Sculptor constellation. It is a relatively loose group and one of the closest groups of galaxies to the Local Group. The centre of the Sculptor Group is approximately 12.7 million light years distant from the Milky Way. The brightest members of the Sculptor Group are the Sculptor Galaxy (NGC 253), the spiral galaxies NGC 247, NGC 7793, the dwarf barred spiral galaxy NGC 625 in Phoenix constellation, and the barred irregular galaxy PGC 6430. The Sculptor Galaxy is an intermediate spiral galaxy in Sculptor. It is undergoing a period of intense star formation. The Sculptor Galaxy (NGC 253), a barred spiral galaxy and the largest member of the group, lies near the border between Sculptor and Cetus. The galaxy has a visual magnitude of 8.0 and is approximately 11.4 million light years distant from the solar system. It is one of the brightest galaxies in the sky. The constellation also contains the Sculptor Dwarf, a dwarf galaxy which is a member of the Local Group, as well as the Sculptor Group, the group of galaxies closest to the Local Group. Another prominent member of the group is the irregular galaxy NGC 55. It is an irregular galaxy with an apparent magnitude of 15.5, located about 13.4 million light-years from Earth. One unique galaxy in Sculptor is the Cartwheel Galaxy, at a distance of 500 million light-years. The result of a merger around 300 million years ago, the Cartwheel Galaxy has a core of older, yellow stars, and an outer ring of younger, blue stars, which has a diameter of 100,000 light-years. The smaller galaxy in the collision is now incorporated into the core, after moving from a distance of 250,000 light-years. The shock waves from the collision sparked extensive star formation in the outer ring. The Cartwheel Galaxy was discovered by the Swiss astronomer Fritz Zwicky in 1941. Abell 2744, also known as Pandora’s Cluster, is a giant cluster of galaxies in Sculptor. The cluster is the result of at least four smaller galaxy clusters piling up over a period of 350 million years. It was nicknamed Pandora’s Cluster because the collision triggered a number of different and strange phenomena. Abell 2744 is located at a distance of 3,982 million light years from Earth. Most of its mass is accounted for by dark matter (75%) and hot gas (about 20%), while the galaxies make up less than 5%. NGC 300 is one of the brightest spiral galaxies in the direction of the Sculptor Group. It has an apparent magnitude of 9.0 and is about 6.07 million light years distant from the Sun. Like NGC 55, the galaxy does not really belong to the Sculptor Group but is located in the foreground. The galaxy has an X-ray source at the core, designated NGC 300 X-1. The source is believed to be a Wolf-Rayet black hole binary system similar to the one in the galaxy IC 10 located in Cassiopeia constellation. NGC 288 is a globular cluster in Sculptor constellation. It has an apparent magnitude of 9.37 and is approximately 28,700 light years distant from Earth. It lies about 1.8 degrees to the southeast of the Sculptor Galaxy and 37′ to the north-northeast of the South Galactic Pole. NGC 24 is a spiral galaxy with an apparent magnitude of 12.4. It is approximately 22.5 million light years distant from the solar system. ESO 540-030 is a dwarf galaxy in Sculptor. It is one of the galaxies in the Sculptor Group. It is approximately 11 million light years distant from the Sun. The galaxy is not an easy object to observe because there are five bright stars located in the foreground and several galaxies in the background. The Giant Squid Galaxy is a barred spiral galaxy approximately 60 million light years away. It has an apparent magnitude of 10.40. The galaxy was discovered by the Scottish astronomer James Dunlop in 1828 and independently found by John Herschel six years later. NGC 134 has a warped disc and a trail of gas that appears to have been stripped from the top edge of the disc, indicating that the galaxy had an encounter with another galaxy. On June 20, 2009, a supernova was observed in the galaxy. Designated SN 2009gj, it was classified as a Type IIb supernova. It reached a peak apparent magnitude of 15.9. NGC 613 is a barred spiral galaxy 67.5 million light years away. It has an apparent magnitude of 10 and an apparent size of 5’.2 x 2’.6. The galaxy is an outlying member of the Sculptor Group. NGC 613 was discovered by William Herschel in 1798 and later independently discovered and catalogued by James Dunlop. Credits: The Constellation Guide, Wikipedia.