Lambda_Serpentis
Lambda Serpentis
Star in the constellation Serpens
Lambda Serpentis, Latinized from λ Serpentis, is a star in the constellation Serpens, in its head (Serpens Caput). It has an apparent visual magnitude of 4.43,[2] making it visible to the naked eye. Based upon parallax measurements, this star lies at a distance of about 38.9 light-years (11.9 parsecs) from Earth.[1] Lambda Serpentis is moving toward the Solar System with a radial velocity of 66.4 km s−1.[4] In about 166,000 years, this system will make its closest approach of the Sun at a distance of 7.371 ± 0.258 light-years (2.260 ± 0.079 parsecs), before moving away thereafter.[12]
This star is 6% larger and 14% more massive than the Sun, although it has a similar stellar classification.[1] It is shining with nearly double the Sun's luminosity and this energy is being radiated from the star's outer atmosphere at an effective temperature of 5,884 K.[9] A periodicity of 1837 days (5.03 years) was suspected by Morbey & Griffith (1987),[13] but it is probably bound to stellar activity. However, McDonald Observatory team has set limits to the presence of one or more exoplanets[13] around Lambda Serpentis with masses between 0.16 and 2 Jupiter masses and average separations spanning between 0.05 and 5.2 Astronomical Units.