Sculptor is a faint southern sky constellation that was created by French astronomer Nicolas Louis de Lacaille from his observatory in South Africa during the 18th century. Its brightest star, Alpha Sculptoris, is a blue-white giant situated 780 light years with an apparent magnitude of just 4.30, but the constellation does contain a number of interesting deep-sky objects, such as the Sculptor Group of Galaxies, and the Cartwheel Galaxy.
Sculptor contains the South Galactic Pole, which lies at -90° to the galactic plane, which is where the majority of the stars in our Milky Way galaxy are concentrated. Conversely, the North Galactic Pole is located at + 90°in the constellation of Coma Berenices, with both poles pointing in the direction of deep intergalactic space.
Sculptor is the 36th largest constellation, taking up an area of 475 square degrees, or 1.2% of the night sky. It can be seen by observers situated between +50° and -90° of latitude, although best seen in November, while from northern locations south of +50°, Sculptor is an autumn constellation visible from September to January. It is bordered by the constellations of Aquarius and Cetus to its north, as well as Fornax (east), Grus (southwest), Phoenix (south), and Piscis Austrinus (west).
Lacaille Constellations Family
In the 1750s, Nicolas-Louis de Lacaille introduced 14 new constellations which he named to commemorate various scientific instruments and apparatuses, including Apparatus Sculptoris (“the sculptor’s studio”), which was later shortened to just Sculptor. The others include Antlia, Caelum, Circinus, Fornax, Horologium, Microscopium, Norma, Octans, Pictor, Reticulum and Telescopium, while he named Mensa after Table Mountain in South Africa, where he often enjoyed taking a walk.
– Alpha Sculptoris, the constellation’s brightest star, is a blue-white giant (B7 IIIp) located 780 light years from our solar system. It shines with a visual magnitude of 4.30, although as a SX Arietis variable star its
brightness can fluctuate by around 0.1 magnitudes over a one day period. Alpha Sculptoris has around 7 times our sun’s radius, 5 times its mass, and 1,500 times its luminosity.
– Beta Sculptoris, the second brightest star in Sculptor, is a blue-white subgiant (B9.5IV) found 178 light years distant of magnitude 4.38. It is about twice the Sun’s size, with 3 times its mass, and 82 times its brightness.
– Gamma Sculptoris, the constellation’s third brightest star, is an orange giant (K1III) situated 179 light years from Earth with an apparent magnitude of 4.41. This 1.3 billion year old star is around 14 times bigger than the Sun, with twice its mass, and 74 times its luminosity.
Other stars of interest in Sculptor includes the multiple stars system Epsilon Sculptoris, Lambda Sculptoris, and Kappa Sculptoris; the triple star system Delta Sculptoris; the binary star Zeta Sculptoris; the yellow dwarf stars HD 4208, HD 4113, HD 9578, and WASP-8; the orange giant Iota Sculptoris; and the red giants Eta Sculptoris, and R Sculptoris.
Notable Deep-Sky Objects
Sculptor may not contain any Messier objects, but it is home to a number of interesting deep-sky objects, such as the globular cluster NGC 288, which is situated 28,700 light years away from Earth and shines with a magnitude of 9.37; and the open cluster Blanco 1, which is 150 million years old, 850 light years distant, and contains around 300 stars. The constellation also contains several galaxies, including:
– Sculptor Group is a group of 13 galaxies that at 12.7 million light years away from the Milky Way is one of the closest to the Local Group. Its brightest members include the Sculptor Galaxy (NGC 253), NGC 247, NGC 7793, PGC 6430, and NGC 625 in the constellation of Phoenix.
– Sculptor Galaxy (NGC 253) is a 1.4 million light year distant intermediate spiral galaxy that shines with an apparent magnitude of 8.0, making it amongst the brightest galaxies in the night sky. It can be viewed using binoculars, and in a 12 inch telescope can be resolved into a long mottled disc with an oval bulge. Other names given to the Sculptor Galaxy include the Silver Coin Galaxy, and Silver Dollar Galaxy.
– Cartwheel Galaxy is a stunning looking lenticular and ring galaxy found 500 million light years distant with an apparent magnitude of 15.2. It is around 150,000 light years wide, with its unusual shape a result of a collision with a smaller galaxy, with the ensuing shock waves producing its dramatic cartwheel shape.
Amongst the numerous other galaxies in Sculptor is the Sculptor Dwarf Elliptical Galaxy, the Sculptor Dwarf Irregular Galaxy, the Southern Cigar Galaxy (NGC 55), the Giant Squid Galaxy, NGC 134 NGC 7, NGC 10, NGC 24, NGC 300, NGC 613, NGC 7793, to name but a few.