HD 107148 is a wide

binary star A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in wh ...

system in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

of Virgo. A pair of

exoplanet An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...

s have been confirmed in orbit around the brighter star. This system is located at a distance of 161

light year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s from the Sun based on

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...

measurements, and is drifting further away with a

radial velocity The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the temporal rate of change, rate of change of the distance or Slant range, range between the two points. It is e ...

of 25.2 K. Although having an absolute magnitude of 4.47, at that range the system is too faint to be visible with the naked eye, having an apparent visual magnitude of 8.01. The brighter primary member, designated component A, has a spectrum that presents as a

G-type main-sequence star A G-type main-sequence star (Spectral type: G-V), also often, and imprecisely called a yellow dwarf, or G star, is a main-sequence star (luminosity class V) of spectral type G. Such a star has about 0.9 to 1.1 solar masses and an effective temp ...

, a yellow dwarf, with a

stellar classification In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...

of G5V. The star is about 4 billion years old and is spinning with a

projected rotational velocity Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface. The rotation of a star produces an equatorial bulge ...

of 1.2 km/s. Based on the abundance of iron, a measure of the star's

metallicity In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal physical matter in the Universe is either hydrogen or helium, and astronomers use the word ''"metals"'' as a ...

, it is twice as enriched with heavy elements than the Sun. The star exhibits a magnetic activity cycle with a period around 6 years. 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 The photosphere is a star's outer shell from which light is radiated. The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it ...

at an effective temperature of 5,789 K. In 2012, a comoving white dwarf stellar companion ''HD 107148 B'' was detected at projected separation of 1,790 AU, and was confirmed in 2014. It is a 0.6 remnant core of the former 1.8 star with a cooling age of . This was formerly the primary component of this system before it ejected much of its mass.

Planetary system

In 2006, a discovery of Saturn-mass planet was announced. Another Neptune-sized planet was discovered in 2021, together with significantly refined orbit of HD 107148 b. HD 107148 should not be confused with

HD 108147 HD 108147, also known as Tupã, is a 7th magnitude star in the constellation of Crux in direct line with and very near to the bright star Acrux or Alpha Crucis. It is either a yellow-white or yellow dwarf (the line is arbitrary and the ...

located in Crux constellation, which also has an extrasolar planet discovered in 2000.

References

{{DEFAULTSORT:HD 107148 G-type main-sequence stars Planetary systems with two confirmed planets Binary stars Virgo (constellation) BD−02 3497 107148 060081 J12191349-0319112

Planetary system

See also

References