Η_Microscopii
Eta Microscopii
Star in the constellation Microscopium
Eta Microscopii, Latinised as η Microscopii, is a solitary[7] star in the constellation Microscopium. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.53.[2] The star is located around 910 light-years distant from the Sun based on parallax, and is drifting further away with a radial velocity of +22 km/s.[1]
This is an aging giant star with a stellar classification of K3 III,[3] indicating that it has exhausted the supply of hydrogen at its core then cooled and expanded. At present it has around 47[1] times the girth of the Sun. The star is radiating 735 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,365 K.[1]
Multiple star catalogues list two optical companions.[8] Two arc-minutes away, the 8th magnitude HD 200733 is a main sequence star much closer to Earth than η Microscopii.[9] A 14th-magnitude star one arc-minute from η Microscopii is a background object.[10]