The primary star GJ 569A is orbited by the much fainter (3.7 magnitudes) secondary GJ 659B at a projected separation of 5.92 arcseconds, discovered in 1988.[11] The star GJ 569B (BD+16 2708B) itself is a close binary system of two high-mass brown dwarfs in a 2.4-year orbit,[12] and a small (0.538±0.048) magnitude difference between components.[13] The orbital plane of close binary GJ 569Ba and GJ 569Bb is expected to precess at timescales of about 100 thousand years due to the gravitational influence of GJ 569A.[6]
Properties
The primary star Gliese 569A is a flare star.[1] The nature of the brown dwarf binary Gliese 569B is highly uncertain, and it was even suspected Gliese 569Ba itself may be either a low-mass star or a binary object. But with a mass about 8-9% that of the Sun means it may possibly be a binary of two extremely low mass ultra-cool dwarf stars that are extremely dim, dim enough to look like a brown dwarf.[7] Both brown dwarfs are weakly variable, likely due to starspot activity.[12]
^Samus, N. N.; Durlevich, O. V.; et al. (2009), "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)", VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S, 1: B/gcvs, Bibcode:2009yCat....102025S
^ abcdefKonopacky, Q. M.; Ghez, A. M.; Fabrycky, D. C.; MacIntosh, B. A.; White, R. J.; Barman, T. S.; Rice, E. L.; Hallinan, G.; Duchêne, G. (May 2012), "Rotational velocities of individual components in very low mass binaries", The Astrophysical Journal, 750 (1): 14, arXiv:1202.5555, Bibcode:2012ApJ...750...79K, doi:10.1088/0004-637X/750/1/79, S2CID51026693
