HD 74180
HD 74180 is a single star in the constellation Vela. It is a yellow-white F-type supergiant with a mean apparent magnitude of +3.81 and a spectral classification F8Ib. Estimates of its distance to Earth vary between 3,200 and 8,300 light-years.
Properties
b Velorum has been classified as a suspected α Cygni variable star which varies by only 0.06 magnitude. There are possible periods near 53, 80, and 160 days, but the variation is largely irregular. It lies less than a degree from the small open cluster NGC 2645, but is not a member.Several studies have considered b Velorum to be a highly luminous supergiant or hypergiant with an early F spectral type, for example F2 Ia+, F0 Ia, and F4 I. There were corresponding luminosity estimates of. A 2015 study used the Barbier-Chalonge-Divan system to derive a luminosity of and a cooler less luminous F8 Ib spectral type.
Distance and size
Multiple papers give different distances for b Velorum. Bailer-Jones et al. give a distance of about . The Hipparcos spacecraft give a parallax of, translating into a distance of. Aidelman et al. give a distance of. At the Hipparcos distance, bVelorum has its apparent brightness diminished by 1.11magnitudes due to interstellar extinction.b Velorum has an angular diameter estimated at. The physical size depends on the star's distance, and could be assuming the distance of Aidelman et al., assuming the Hipparcos distance, or even assuming the Bailer-Jones et al. distance.