PP Carinae


p Carinae is a star in the southern constellation of Carina. It has the variable [star designation] PP Carinae and, at an apparent [visual magnitude] of +3.3, is readily visible to the naked eye from the southern hemisphere. From the observed parallax shift of this star as the Earth orbits the Sun, its distance can be estimated as roughly with a 6% margin of error. It is considered to be a member of the open cluster IC 2602 although it lies well outside the core visible group of stars.
File:PPCarLightCurve.png|thumb|left|A light curve for PP Carinae, plotted from Transiting Exoplanet [Survey Satellite|TESS] data
The star is a B-type [main sequence star] with a stellar classification of B4 Vne. The 'ne' suffix indicates it is a rapidly rotating Be star that is surrounded by hot circumstellar gas. This material adds emission lines to the spectrum of the star. It has a projected rotational velocity of, with about 7.6 times the mass and eight times the radius of the Sun. Alan [William James Cousins] announced the discovery that this star is a variable star, in 1951. This star is classified as a Gamma Cassiopeiae-type variable and its brightness varies from magnitude +3.22 to +3.55.
In most versions of its asterism, the neighbouring bright stars, thus plotted along the imaginary hull forming Carina are Theta Carinae, to the south, and V337 (also known as lower case q) Carinae to the east, of second and third magnitude respectively.