Omicron Capricorni (ο Capricorni) is a widebinary star[11] system in theconstellationCapricornus.[12] The brighter component has anapparent visual magnitude of +5.94,[2] which is near the lower limit on stellar brightness that still can be seen with the naked eye. Based upon an annualparallax shift of 15.07 mas as seen from Earth,[1] this system is located roughly 220 light-years from theSun. Large but uncertain discrepancies in the parallax measurements fromHipparcos may indicate, weakly, that there is a third, unseen companion in the system.[11]
Both visible components are white-huedA-type main-sequence stars.[3] The primary, component A, sometimes calledο1 Capricorni, has anapparent magnitude of +5.94, while the companion, component B orο2 Capricorni, has an apparent magnitude of +6.74.[2] The two stars are currently separated by 21.91[11]arcseconds, corresponding to aprojected separation of around2,100 AU.[13] At the estimated age of around 118[6] million years old, both components are spinning rapidly: component A has aprojected rotational velocity of 276 km/s, while component B is 136 km/s.[7]
^abcdefghJohnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars",Communications of the Lunar and Planetary Laboratory,4 (99): 99,Bibcode:1966CoLPL...4...99J.
^abcHouk, Nancy; Smith-Moore, M. (1978),Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan,Bibcode:1988mcts.book.....H.
