Caelum

Caelum /ˈsiːləm/ is a faint constellation in the southern sky, introduced in the 1750s by Nicolas Louis de Lacaille. Its name means "the chisel" in Latin, and it was formerly known as Caelum Scalptorium ("the engraver's chisel"). It is the eighth-smallest constellation, and subtends a solid angle of around 0.038 steradians, just less than that of Corona Australis. Due to its small size and location away from the plane of the Milky Way, Caelum is a rather barren constellation, with few objects of interest. The constellation's brightest star, Alpha Caeli, is only of magnitude 4.45, and only one other star (Gamma1 Caeli) is brighter than magnitude 5. Other notable objects in Caelum are RR Caeli, a binary star with one planet approximately 20.13 parsecs (65.7 ly) away; X Caeli, a Delta Scuti variable that forms an optical double with Gamma1 Caeli; and HE0450-2958, a Seyfert galaxy that at first appeared as just a jet with no host galaxy visible. ... Caelum is bordered by Dorado and Pictor to the south, Horologium and Eridanus to the east, Lepus to the north, and Columba to the west. ... The International Astronomical Union (IAU) adopted the three-letter abbreviation "Cae" for the constellation in 1922. ... Stars. Caelum is a faint constellation, having no star brighter than fourth magnitude and only two brighter than fifth magnitude. Lacaille gave six stars Bayer designations, labeling them Alpha to Zeta in 1756, but omitted Epsilon and designated two nearby stars as Gamma. Bode extended the designations to Rho for other stars but most have fallen out of use. Caelum is too far south for any of its stars to bear Flamsteed designations. The brightest star, Alpha Caeli, is a double star, containing an F-type main-sequence star of magnitude 4.45 and a red dwarf of magnitude 12.5, 20.17 parsecs (65.8 ly) from Earth. Beta Caeli, another F-type star of magnitude 5.05, is further away, being located 28.67 parsecs (93.5 ly) from Earth. Unlike Alpha, Beta Caeli is a subgiant star, slightly evolved from the main sequence. Delta Caeli, also of magnitude 5.05, is a B-type subgiant and is much farther from Earth, at 216 parsecs (700 ly). Gamma1 Caeli is a double star with a red giant primary of magnitude 4.58 and a secondary of magnitude 8.1. ... Deep-sky objects. Due to its small size and location away from the plane of the Milky Way, Caelum is rather devoid of deep-sky objects, and contains no Messier objects. The only deep-sky object in Caelum to receive much attention is HE0450-2958, an unusual Seyfert galaxy. Originally, the jet's host galaxy proved elusive to find, and this jet appeared to be emanating from nothing. Although it has been suggested that the object is an ejected supermassive black hole, the host is now agreed to be a small galaxy that is difficult to see due to light from the jet and a nearby starburst galaxy. [Caelum. Wikipedia]