HIP 81208

HIP 81208

The HIP 81208 system as captured by VLT, showing all four stellar and substellar components
Observation data
Epoch J2000[1]      Equinox J2000[1]
Constellation Scorpius
Right ascension 16h 35m 13.83929s
Declination −35° 43′ 28.7256″
Apparent magnitude (V) 6.64[2]
Characteristics
Spectral type B9V[3] + M5 + M4[4]
U−B color index −0.208±0.009[4]
B−V color index −0.049±0.007[4]
Astrometry
Proper motion (μ) RA: -9.701[1] mas/yr
Dec.: -25.913[1] mas/yr
Parallax (π)6.8424 ± 0.0475 mas[1]
Distance477 ± 3 ly
(146 ± 1 pc)
Absolute magnitude (MV)0.292±0.080[4]
Orbit[4]
PrimaryHIP 81208 A
CompanionHIP 81208 B
Period (P)246.9+251.3
−95.4[5] 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[4]
PrimaryHIP 81208 A
CompanionHIP 81208 C
Period (P)2232.4+4429.4
−1213.6[5] 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
Mass2.58±0.06[5] M☉
Radius2.213±0.121[4] R☉
Luminosity60.469±4.46[4] L☉
Surface gravity (log g)4.201±0.011[4] cgs
Temperature10840±220[4] K
Age17+3
−4[4] Myr
HIP 81208 B
Mass67+6
−7[4] MJup
Temperature2900[4] K
HIP 81208 C
Mass0.135+0.010
−0.013[4] M☉
Temperature3165+40
−60[4] 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[6]
Database references
SIMBADHIP 81208

HIP 81208 (HD 149274) is a young triple or quadruple[a] 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.[7] 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.

  1. ^ a b c d Cite error: The named reference EDR3 was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference TYC2000 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Houk1982 was invoked but never defined (see the help page).
  4. ^ a b c d e f g h i j k l m n o Cite error: The named reference beast was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Chomez2023 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Hoogerwerf2000 was invoked but never defined (see the help page).


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