HD 149989

Lore & Background

HD 149989 was discovered to be variable from Hipparcos data, with the discovery published in 1997 in the list of periodic variables seen by that satellite. In 1998, Conny Aerts and colleagues identified it as a Gamma Doradus type star, with a period of 0.42658 days. It received its variable star designation V872 Arae in March 2000.

The star is an A-type main-sequence star with a stellar classification of A9 V. A 2016 survey of Gamma Doradus stars found a class of , where the 'nn' indicates nebulous lines due to rapid rotation and the 'm-4' means a metal-poor star with metal lines matching a class of A7. It is about 1.1 billion years old and spins with a projected rotational velocity of 136 km/s.

Reader's Guide

HD 149989 is significant as a Gamma Doradus variable, a class of pulsating stars that vary in brightness due to non-radial gravity-mode pulsations. Its discovery via Hipparcos data and subsequent classification by Aerts et al. in 1998 contributed to the understanding of this variable star type. The star's rapid rotation (136 km/s) and metal-poor nature, as noted in a 2016 survey, provide insights into the properties of such variables. Its location near the border of Ara and Norma, and its designation as V872 Arae, place it within the catalog of variable stars. The star's distance of 167 light years and radial velocity of 46 km/s indicate it is moving away from the Sun. As an A9 V star, it represents a specific stage of stellar evolution, with an age of about 1.1 billion years. The star's variability, with a period of 0.42658 days, makes it a target for studies of stellar pulsation and rotation.

Did You Know?

• HD 149989 has a variable star designation V872 Arae.
• It was discovered to be variable from Hipparcos data, published in 1997.