Astronomy

X Carinae – a Beta Lyrae variable in the Constellation Carina

X Carinae – a Beta Lyrae variable in the Constellation Carina

X Carinae is a Beta Lyrae variable in the Carina constellation. It’s a yellow hypergiant. It is visible to the naked eye and can be found in the constellation Carina. It is one of the largest known stars, with a diameter of nearly 1 billion kilometers, or 700 times that of the Sun. It has a magnitude range of 7.9 to 8.65 over a period of about 1.08 days. It has a brightness 316,000 times that of the Sun.

The yellow hypergiant x Carinae is located in the constellation Carina. When viewed from Earth, it is the 10th largest known star by radius and the brightest of the rare yellow hypergiant class. It is a G-type star with a mean apparent magnitude of +3.93 and a low-amplitude variable star. At 3500 light-seconds, the x Carinae system also contains two smaller stars and a single gas giant, providing excellent views of the hypergiant.

X Carinae is a yellow hypergiant star. It is 700 times larger than the Sun and it is one of the largest known stars. It is visible to the eye and is seen in the Carina constellation.

Variability

The radial velocity of X Carinae has long been known to vary, but variations in its brightness were previously unknown. Some observers noticed variations in brightness, while others found it to be constant. It was formally designated as a variable star in 1981, and it is listed as a possible δ Cephei variable in the General Catalogue of Variable Stars. It has been described as a pseudo-Cepheid, a supergiant with pulsations similar to but less regular than those of a Cepheid.

The star was classified as an α Cygni variable after Hipparcos photometry revealed clear variation with a maximum range of 0.12 magnitudes. A time span of 556 days has been proposed, but it is not entirely consistent. It is now classified as a semiregular or irregular supergiant.

Properties

X Carinae is the brightest yellow hypergiant in the night sky, visible with the naked eye and brighter than Rho Cassiopeiae, which is visible from much of the northern hemisphere. It is 6,200 light-years away from Earth and has a radius roughly 500 times that of the Sun. Because of its massive size, X Carinae is over 200,000 times as bright as the sun. The low infrared excess suggests that X Carinae is cooling into a red supergiant phase, which is less common than yellow hypergiants evolving into hotter temperatures.