Beta Hydri

At a distance of 13°, it is the closest easily visible star to the south celestial pole, and around 150 BC it was within two degrees of it, which made it the southern pole star.

Characteristics

The spectrum of this star matches a stellar classification of G2 IV, with the luminosity class of 'IV' indicating this is a subgiant star. As such, it is a slightly more evolved star than the Sun, with the supply of hydrogen at its core becoming exhausted. Around 113% of the mass of the Sun, it has expanded to 184% of the Sun's radius, with more than three times the Sun's luminosity. It is one of the oldest stars in the solar neighborhood, with an age between 6.1 and 7.5 billion years. This star bears some resemblance to what the Sun might look like in the far distant future, making it an object of interest to astronomers.

Beta Hydri has a strong magnetic field, which is not common for evolved stars that lost most of it during their main sequence phase. It is believed that during the subgiant phase, the star temporarily re-established a large magnetic field.