HIP 81208
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 16h 35m 13.83929s |
| Declination | −35° 43′ 28.7256″ |
| Apparent magnitude (V) | 6.64 |
| Characteristics | |
| Spectral type | B9V + M5 + M4 |
| U−B color index | −0.208±0.009 |
| B−V color index | −0.049±0.007 |
| Astrometry | |
| Proper motion (μ) | RA: -9.701 mas/yr Dec.: -25.913 mas/yr |
| Parallax (π) | 6.8424±0.0475 mas |
| Distance | 477 ± 3 ly (146 ± 1 pc) |
| Absolute magnitude (MV) | 0.292±0.080 |
| Orbit | |
| Primary | HIP 81208 A |
| Companion | HIP 81208 B |
| Period (P) | 246.9+251.3 −95.4 yr |
| Semi-major axis (a) | 53.98+32.22 −15.00 AU |
| Eccentricity (e) | 0.33+0.26 −0.22 |
| Inclination (i) | 46.61+15.71 −19.47° |
| Orbit | |
| Primary | HIP 81208 A |
| Companion | HIP 81208 C |
| Period (P) | 2232.4+4429.4 −1213.6 yr |
| Semi-major axis (a) | 234.27+168.65 −68.96 AU |
| Eccentricity (e) | 0.38+0.29 −0.26 |
| Inclination (i) | 128.16+19.47 −15.36° |
| Details | |
| HIP 81208 A | |
| Mass | 2.58±0.06 M☉ |
| Radius | 2.213±0.121 R☉ |
| Luminosity | 60.469±4.46 L☉ |
| Surface gravity (log g) | 4.201±0.011 cgs |
| Temperature | 10840±220 K |
| Age | 17+3 −4 Myr |
| HIP 81208 B | |
| Mass | 67+6 −7 MJup |
| Temperature | 2900 K |
| HIP 81208 C | |
| Mass | 0.135+0.010 −0.013 M☉ |
| Temperature | 3165+40 −60 K |
| Other designations | |
| CD−35°11037, Gaia DR3 6020514769906985728, GC 22284, HD 149274, HIP 81208, SAO 207794, PPM 295214, TIC 280474618, TYC 7357-207-1, GSC 07357-00207, 2MASS J16351384-3543287 | |
| Database references | |
| SIMBAD | HIP 81208 |
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HIP 81208 (HD 149274) is a young triple or quadruple hierarchical star system in the constellation of Scorpius. It consists of a B-type main sequence star (component A), a brown dwarf (B), and a red dwarf (C), the latter two distantly orbiting the primary star. The stars are part of the Scorpius–Centaurus association. In 2023, HIP 81208 C was found to be orbited by a substellar object, which is at the border between being a massive exoplanet and a low-mass brown dwarf. This made HIP 81208 the first stellar binary with substellar objects orbiting both stellar components ever discovered by direct imaging. With an apparent magnitude of 6.64, it is barely visible by the naked eye under dark skies.