Nu2 Canis Majoris

Nu² Canis Majoris is a star in the southern constellation of Canis Major. Its name is a Bayer designation that is Latinized from ν² Canis Majoris, and abbreviated Nu² CMa or ν² CMa. With an apparent visual magnitude of 3.96, it is bright enough to be seen with the naked eye, close to Sirius. An annual parallax shift of around 50.63 mas, as measured by the Gaia spacecraft, implies a distance of. It is drifting further away with a line of sight velocity of +2.6 km/s. The star has two confirmed exoplanets and no known stellar companion.
This is an aging giant star with a stellar classification of K1 III, having exhausted the hydrogen at its core then expanded. It is believed to be on the early ascent of the red giant branch and has not yet undergone helium flash. This star is around 4.6 billion years old and is spinning slowly with a projected rotational velocity of 2 km/s. It has 1.4 times the mass of the Sun and has grown to 5.2 times the Sun's radius. The star is radiating 13 the luminosity of the Sun from its photosphere at an effective temperature of 4,790 K.

Planetary system

By measuring periodic variations in the radial velocity of the host star between 2009 and 2010, the Pan-Pacific Planet Search program was able to identify a planet orbiting Nu² Canis Majoris. An orbital fit produced a minimum mass estimate of with an orbital period of 2.1 years and an eccentricity of 0.23. Star spots were ruled out as a source for the signal with a false-alarm probability of 98.7%. Further observations through 2019 detected the planet, as well as a secondary planet c in a 4:3 orbital resonance with planet b.

Chinese name

In Chinese astronomy, ν² Canis Majoris is called 野雞, Pinyin: Yějī, meaning Wild Cockerel, because this star is marking itself and stand alone in Wild Cockerel asterism, Well mansion. 野雞, westernized into Ya Ke. According to R. H. Allen, the name Ya Ke is an asterism consisting ο¹ Canis Majoris and π Canis Majoris, with other small stars in the body of the Dog.