Gliese 179 – a Small Red Dwarf Star

In the equatorial constellation of Orion, Gliese 179 is a small red dwarf star with an exoplanetary companion. It’s a 12th magnitude M-type main-sequence star in the constellation Orion, about 40 light-years away. With an apparent visual magnitude of 11.94, it is far too faint to be seen with the naked eye. This star is smaller, cooler, fainter, and has a lower mass than the Sun. It also has twice the metal content of the Sun.

Based on parallax measurements, the system is 80.9 light-years from the Sun, but it is moving closer with a radial velocity of –9 km/s. A gas giant planet was discovered in orbit around the star in 2009. It is a high proper motion star, traversing the celestial sphere at an angular rate of 0.370″·yr−1.

This is an M-type main-sequence star with the stellar designation M2V. Based on the star’s motion through space, it is estimated to be 4.6 billion years old. It has a projected rotational velocity of 4 km/s and is chromospherically active. This star is smaller and less massive than our Sun, but it contains more metal. At an effective temperature of 3,424, it radiates only 1.6 percent of the Sun’s luminosity from its photosphere.

Gliese 179 b is an extrasolar planet that orbits the M-type main-sequence star Gliese 179, which is located in the constellation Orion about 40 light-years away. This planet has a minimum mass slightly less than Jupiter and orbits the star at 2.41 AU or 361 Gm with an eccentricity slightly less than Pluto. The planetary distance varies between 1.90 and 2.92 AU. On November 13, 2009, this planet was discovered using the radial velocity method from a spectrograph at Keck Observatory.

A Jovian-type planet was discovered in orbit around the star in 2009, making it one of the few red dwarfs known to host a planet of this size. The radial velocity data suggested that there could be another companion. Tidal interactions with the host star are not expected to affect this planet due to its orbital distance. In 2017, a second candidate planet was discovered and confirmed in 2019. This is a possible super-Earth with a minimum mass of about five times that of the Earth.