AR Cephei

AR Cephei is a red hypergiant variable star located in the constellation Cepheus. It is one of the largest known stars in the Milky Way, with an estimated radius exceeding 1,000 times that of the Sun. Its variability is classified as an irregular or semi-regular type.

AR Cephei is extremely luminous, radiating hundreds of thousands of times more energy than the Sun. However, much of this energy is emitted in the infrared portion of the spectrum due to its relatively cool surface temperature for a star of its size. This lower temperature is characteristic of red supergiants and hypergiants.

Observations of AR Cephei are subject to uncertainties due to its distance, the obscuring effects of interstellar dust, and the difficulties in precisely measuring the sizes of such large and diffuse objects. Estimates of its distance place it several thousand light-years away from Earth.

The fate of AR Cephei is likely to be a supernova explosion, given its immense mass and evolved state. This event would mark the end of its life cycle and contribute heavy elements to the surrounding interstellar medium. Its large distance means a supernova would not pose a threat to Earth.