HD 131496 is an

evolved Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

subgiant star A subgiant is a star that is brighter than a normal main-sequence star of the same spectral class, but not as bright as giant stars. The term subgiant is applied both to a particular spectral luminosity class and to a stage in the evolution o ...

in the constellation Boötes. With an apparent visual magnitude of 7.9 it is too faint to be visible to the naked eye. Stars like HD 131496 are sometimes referred to as "retired A-stars", since they would have been A-type stars while on the main sequence. This name is most commonly used in connection with the search for

extrasolar planets 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 ...

, where they are useful because these evolved stars are cooler and have more

spectral lines A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to iden ...

than their main sequence counterparts, making planet detection easier.

Planetary system

A planet with a mass roughly 2.2 times that of Jupiter orbiting at a distance of 2.09

astronomical unit The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits ...

s (AU) once every 883 days was discovered in 2011. HD 131496 and its planet, HD 131496b, were chosen as part of the 2019

NameExoWorlds NameExoWorlds (also known as IAU NameExoWorlds) is the name of various projects managed by the International Astronomical Union (I.A.U.) to encourage names to be submitted for astronomical objects, which would later be considered for official ad ...

campaign organised by the

International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...

, which assigned each country a star and planet to be named. HD 131496 was assigned to

Andorra , image_flag = Flag of Andorra.svg , image_coat = Coat of arms of Andorra.svg , symbol_type = Coat of arms , national_motto = la, Virtus Unita Fortior, label=none (Latin)"United virtue is stro ...

. The winning proposal for the name of the star was Arcalís, after a mountain peak in northern Andorra where the Sun shines through a gap twice a year at fixed dates, leading to its use as a primitive Solar calendar. The planet was named Madriu, after a glacial valley and river in southeastern Andorra that forms the major part of the Madriu-Perafita-Claror

UNESCO The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...

world heritage site A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for h ...

References

{{Stars of Boötes Boötes K-type subgiants Durchmusterung objects 131497 072845 Arcalís Planetary systems with one confirmed planet