HAT-P-15 is a G-type main-sequence star about 630 light-years away. The star is older than Sun yet has a concentration of heavy elements roughly 190% of solar abundance.[3] The star has no noticeable starspot activity.[5]
The spectroscopic survey in 2015 have failed to find any stellar companions to it,[6] yet imaging survey have identified a possibly two companion red dwarf stars at projected separations 1210 and 1370 AU, respectively.[7]
The star was named Berehynia in December 2019 by Ukrainian amateur astronomers.[8]
Planetary system
In 2010 a transiting hot superjovian planet b (named Tryzub in 2019[8]) was detected. It has an equilibrium temperature of 904±20 K.[2] An orbital simulation shows that any planets inward of the orbit of b would spiral inward and be destroyed within a time-span of less than a billion years.[9] The planetary orbit is well aligned with the equatorial plane of the star, misalignment equal to 13±6 degrees.[10]
^ abcKovács, G.; Bakos, G. Á.; Hartman, J. D.; Torres, G.; Noyes, R. W.; Latham, D. W.; Howard, A. W.; Fischer, D. A.; Johnson, J. A.; Marcy, G. W.; Isaacson, H.; Sasselov, D. D.; Stefanik, R. P.; Esquerdo, G. A.; Fernandez, J. M.; Lázár, B. Béky J.; Papp, I.; Sári, P.; Sári, P. (2010), "HAT-P-15b: A 10.9-Day Extrasolar Planet Transiting a Solar-Type Star", The Astrophysical Journal, 724 (2): 866–877, arXiv:1005.5300, Bibcode:2010ApJ...724..866K, doi:10.1088/0004-637X/724/2/866, S2CID119207125
^ abTeske, Johanna K.; Thorngren, Daniel; Fortney, Jonathan J.; Hinkel, Natalie; Brewer, John M. (2019), "Do Metal-Rich Stars Make Metal-Rich Planets? New Insights on Giant Planet Formation from Host Star Abundances", The Astronomical Journal, 158 (6): 239, arXiv:1912.00255, Bibcode:2019AJ....158..239T, doi:10.3847/1538-3881/ab4f79, S2CID208527082
