Alight curve for Ross 458. The main plot, adapted from Shakhovskaya (1969),[12] shows the intensity of a flare relative to the star's quiescent intensity. The inset plot, adapted from Kiraga (2012),[13] shows the periodic variation.
This star was mentioned as a suspected variable byM. Petit in 1957.[14] In 1960,O. J. Eggen classified it as a member of theHyades moving group based on the system's space motion;[15] it is now considered a likely member of the Carina Near Moving Group.[16] Two flares were reported from this star in 1969 byN. I. Shakhovskaya, confirming it as aflare star.[12] It was identified as anastrometric binary in 1994 byW. D. Heintz, who found a period of 14.5 years.[5] The pair were resolved usingadaptive optics in 1999.[5] Early mass estimates placed the companion near the substellar limit, and it was initially proposed as abrown dwarf[17] but is now consideredlate-typered dwarf.[4]
A distant sub-stellar companion to the binary star system was discovered in 2010 as part of a deep infrared sky survey. This is most likely a T8 spectral typebrown dwarf with an estimated rotation period of6.75±1.58 h. The object varies slightly in brightness, which may be due to patchy clouds.[4] The companion lacks detectable oxygen in the atmosphere, implying its formation from sequestrated source or peculiar atmospheric chemistry.[18] Analysis of its chemical composition show it to be similar to that of Ross 458 A, indicating that the object formed in a stellar-like manner.[6]
^abcdeAlekseev, I. Y.; Bondar, N. I. (1997). "Spottedness of the emission-line dwarf stars BF CVn, DT Vir, EQ Vir, and V1396 Cyg from photoelectric and photographic observations".Astronomy Letters.23 (2):257–262.Bibcode:1997AstL...23..257A.
^abcdefghijMeynardie, William W.; Meyer, Michael R.; MacDonald, Ryan J.; Calissendorff, Per; Mullens, Elijah; Zarazua, Gabriel Munoz; Roy, Anuranj; Ganta, Hansica; Gonzales, Eileen C. (2025-09-26). "Ross 458c: Gas Giant or Brown Dwarf?".arXiv:2509.22803 [astro=ph.EP].
^abShakhovskaya, N. I. (July 1969). "Flares of BD +13 2618".Information Bulletin on Variable Stars.361: 1.Bibcode:1969IBVS..361....1S.
^Kiraga, M. (March 2012). "ASAS Photometry of ROSAT Sources. I. Periodic Variable Stars Coincident with Bright Sources from the ROSAT All Sky Survey".Acta Astronomica.62 (1):67–95.arXiv:1204.3825.Bibcode:2012AcA....62...67K.
^Petit, M. (October 1957). "On the International Cooperation for the Study of Flare Variable Stars".Soviet Astronomy.1: 783.Bibcode:1957SvA.....1..783P.
^Gaarn, Josefine; Burningham, Ben; Faherty, Jacqueline K.; Visscher, Channon; Marley, Mark S.; Gonzales, Eileen C.; Calamari, Emily; Bardalez Gagliuffi, Daniella; Lupu, Roxana; Freedman, Richard (2023), "The puzzle of the formation of T8 dwarf Ross 458c",Monthly Notices of the Royal Astronomical Society,521 (4):5761–5775,arXiv:2303.16863,doi:10.1093/mnras/stad753
