Star Constellation Facts: Pictor

Star Constellation Facts: Pictor
Image: © Akira Fujii/David Malin Images

Pictor was named by French astronomer Abbé Nicolas-Louis de Lacaille after spending the period between 1750 and 1754 cataloguing stars of the southern celestial hemisphere while in South Africa. Originally called ‘Equuleus Pictorius’ or “the “painter’s easel,” the name was later changed to just Pictor (“painter”). The brightest star in this constellation is Alpha Pictoris, a white dwarf star located around 97 light years away that shines with an apparent visual magnitude of 3.27.

History

Including Pictor, Lacaille named a total of 14 constellations that could not be seen from Europe, all of which honored instruments symbolising the Age of Enlightenment, with the exception of Mensa (“the table”). The full list includes Antlia, Caelum, Circinus, Fornax, Horologium, Mensa, Microscopium, Norma, Octans, Pictor, Pyxis, Reticulum, Sculptor, and Telescopium. Lacaille also renamed the constellation of Musca.

Location

Pictor is a southern sky constellation that can be seen by observers located between +26° and -90° of latitude. It is the 59th largest of the 88 recognized constellation, and is situated between the night sky’s second brightest star, Canopus in Carina, and the constellations of Dorado and Mensa in which can be seen a small separate galaxy called the Large Magellanic Cloud (LMC). Other nearby constellations include Caelum, Columba, Puppis and Volans. In the northern hemisphere, Pictor is a winter constellation that is best seen in January.

Principal Stars

Pictor Constellation Stars– Alpha Pictoris, the brightest star in Pictor, is a white dwarf star (A8 Vn kA6) situated 97 light years from the Sun with an apparent visual magnitude of 3.27. It is around 660 million years old, and compared to our sun has 2.04 times its mass, 1.6 times its radius, and 13 times its luminosity. Alpha Pictoris is also a fast spinner with a projected rotational velocity of 206 km/s, compared to 2 km/s for the Sun.

– Beta Pictoris, the constellation’s second brightest star, is a white dwarf star (A6V) located 63.4 light-years distant with an apparent visual magnitude of 3.86. It has a solar mass and radius around 1.8 times that of our sun. Beta Pictoris is also just 20 million years old, and is a member of the Beta Pictoris Moving Group, consisting of 28 young stars spread out across 17 stellar systems.

– Gamma Pictoris, the constellation’s third brightest star, is an orange giant (K1III) with an apparent visual magnitude of 4.50 located around 174 light years from our solar system. It is around 11 times bigger than the Sun.

Other notable stars in the constellation Pictor include Delta Pictoris, an eclipsing binary of visual magnitude 4.72 consisting of two blue stars located 1,655 light years away; Kapteyn’s Star, a red dwarf (M1) just 12.76 light years distant with a visual magnitude of 8.853; as well as the orange stars AB Pictoris, HD 40307, and HD 41004.

Notable Deep Sky Objects

Pictor does not contain any Messier objects, and only a handful of deep-sky objects can be observed, including:

NGC 1705-NGC 1705 is an irregular dwarf galaxy that is 2,600 light-years across and 17 million light years distant. It has a visual magnitude of 12.8, and also appear blue in color because of the large clusters of young, hot blue stars that it contains. In fact, this 13 billion years old galaxy contains thousands of both young and old stars, and provides an excellent source for studying the formation and evolution of galaxies.

– Pictor A is a double-lobed radio galaxy 485 million light-years away which at its centre has a supermassive black hole that shoots a spectacular jet of X-rays across 300,000 light years of space. To put that distance into perspective, our own Milky Way is just 100,000 light-years across.

– SPT-CL J0546-5345 is a massive galaxy cluster located 7 billion light-years away that is thought to be around 13.7 billion years old. It is also one of the biggest ever galaxy clusters found at this distance, and consists of 800 trillion stars hosted within hundreds of individual galaxies. Even so, it is likely to be at least four times the size that we can observe today, which would elevate it to one of the most massive clusters yet discovered.

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