Gamma¹ Leonis b is an extrasolar planet located 125.5

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 away in the constellation

Leo Leo or Léo may refer to: Acronyms * Law enforcement officer * Law enforcement organisation * ''Louisville Eccentric Observer'', a free weekly newspaper in Louisville, Kentucky * Michigan Department of Labor and Economic Opportunity Arts an ...

, orbiting the giant star Gamma¹ Leonis.

Discovery

On November 6, 2009, a planetary companion around primary star Gamma¹ Leonis has been announced. Moreover,

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 ...

variations would also hint two strong signals at 8.5 and 1340 days. The former periodicity is likely due to stellar pulsation, whereas the latter could be indicative of the presence of an additional planetary companion with 2.14 Jupiter masses, moderate eccentricity (e=0.13) and located at 2.6 Astronomical Units away from the giant star. Nevertheless, the nature of such a signal is still unclear and further investigations are needed to confirm or rule out an additional substellar companion.

Characteristics

The planet has a minimum mass of 8.78

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...

masses. The true mass, as with the majority of other extrasolar planets discovered by the radial velocity method, is unknown.

References

{{Sky, 10, 19, 58.3, +, 19, 50, 30, 126 Leo (constellation) Giant planets Exoplanets discovered in 2009 Exoplanets detected by radial velocity