69_Orionis
69 Orionis
Star in the constellation Orion
69 Orionis is a single[11] star in the equatorial constellation of Orion, positioned a couple of degrees to the north of Xi Orionis. It has the Bayer designation f1 Orionis; 69 Orionis is the Flamsteed designation. The star is visible to the naked eye as faint, blue-white hued point of light with an apparent visual magnitude of 4.92.[2] It is located approximately 530 light-years from the Sun based on parallax,[1] and is drifting further away with a radial velocity of +22 km/s.[4] In 2015, H. Bouy and J. Alves suggested that it is a member of the newly discovered Taurion OB association.[9]
This object is a B-type main-sequence star with a stellar classification of B5Vn,[3] where the 'n' suffix indicates "nebulous" (broad) lines due to rapid rotation. It has a projected rotational velocity of 285 km/s, compared to a critical velocity of 476±37 km/s; the polar axis is inclined by 64°±16°.[6] This is a known Be star[12] that began behaving as a normal star in November, 1982.[13] It has 6.4 times the mass of the Sun and is radiating around 1,442 times the Sun's luminosity from its photosphere at an effective temperature of 17,090 K.[6]