The brighter primary member, designated component A, has a spectrum that presents as a G-type main-sequence star,[4] a yellow dwarf, with a stellar classification of G5V.[3] The star is about 4 billion years old and is spinning with a projected rotational velocity of 1.2 km/s.[7] Based on the abundance of iron, a measure of the star's metallicity, it is twice as enriched with heavy elements than the Sun. The star exhibits a magnetic activity cycle with a period around 6 years.[9] It has 1.1 times the mass of the Sun and 1.15 times the Sun's radius. HD 107148 is radiating 1.34 times the luminosity of the Sun from its photosphere at an effective temperature of 5,789 K.[6]
In 2012, a comoving white dwarf stellar companion HD 107148 B was detected[10] at projected separation of 1,790 AU, and was confirmed in 2014. It is a 0.6 M☉ remnant core of the former 1.8±0.2 M☉ star with a cooling age of 2.1±0.3 Gyr. This was formerly the primary component of this system before it ejected much of its mass.[4]
Planetary system
In 2006, a discovery of Saturn-mass planet was announced.[11] Another Neptune-sized planet was discovered in 2021, together with significantly refined orbit of HD 107148 b.[9]
HD 107148 should not be confused with HD 108147 located in Crux constellation, which also has an extrasolar planet discovered in 2000.
^ abHouk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
^ abcdefMugrauer, M.; et al. (March 2014), "New wide stellar companions of exoplanet host stars", Monthly Notices of the Royal Astronomical Society, 439 (1): 1063–1070, Bibcode:2014MNRAS.439.1063M, doi:10.1093/mnras/stu044.