HD 106515 is a binary star (and currently visual triple system) in the constellation of Virgo.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Virgo |
| HD 106515 A | |
| Right ascension | 12h 15m 06.5667s[1] |
| Declination | –07° 15′ 26.353″[1] |
| Apparent magnitude (V) | +7.99[2] |
| HD 106515 B | |
| Right ascension | 12h 15m 06.1003s[3] |
| Declination | –07° 15′ 26.587″[3] |
| Apparent magnitude (V) | +8.25[2] |
| Characteristics | |
| HD 106515 A | |
| Spectral type | K0 V[2] |
| HD 106515 B | |
| Spectral type | K1 V[2] |
| Astrometry | |
| HD 106515 A | |
| Radial velocity (Rv) | 20.66±0.11[4] km/s |
| Proper motion (μ) | RA: −251.469[1] mas/yr Dec.: −51.330[1] mas/yr |
| Parallax (π) | 29.3148 ± 0.0297 mas[1] |
| Distance | 111.3 ± 0.1 ly (34.11 ± 0.03 pc) |
| HD 106515 B | |
| Radial velocity (Rv) | 19.94±0.11[4] km/s |
| Proper motion (μ) | RA: −244.603[3] mas/yr Dec.: −67.744[3] mas/yr |
| Parallax (π) | 29.3908 ± 0.0294 mas[3] |
| Distance | 111.0 ± 0.1 ly (34.02 ± 0.03 pc) |
| Absolute magnitude (MV) | 4.62[5] |
| Orbit[2] | |
| Primary | HD 106515 A |
| Companion | HD 106515 B |
| Period (P) | 4802.1+2397 −1141 yr |
| Semi-major axis (a) | 9.822+2.688 −1.329" (345+95 −47 AU) |
| Eccentricity (e) | 0.420+0.106 −0.104 |
| Inclination (i) | 164.45+3.5 −11.3° |
| Longitude of the node (Ω) | 92.06+45.08 −2.67° |
| Periastron epoch (T) | 2376.4+44.4 −78.9 |
| Argument of periastron (ω) (secondary) | 250.50+38.22 −14.07° |
| Details[6] | |
| HD 106515 A | |
| Mass | 0.888±0.018 M☉ |
| Radius | 0.910±0.009 R☉ |
| Luminosity | 0.68±0.05[3] L☉ |
| Surface gravity (log g) | 4.39±0.18 cgs |
| Temperature | 5364±57 K |
| Metallicity [Fe/H] | +0.016±0.009 dex |
| Rotational velocity (v sin i) | 1.7[7] km/s |
| Age | 9.233±2.133 Gyr |
| HD 106515 B | |
| Mass | 0.861±0.015 M☉ |
| Radius | 0.865±0.015 R☉ |
| Luminosity | 0.55±0.05[3] L☉ |
| Surface gravity (log g) | 4.30±0.20 cgs |
| Temperature | 5190±58 K |
| Metallicity [Fe/H] | +0.022±0.010 dex |
| Rotational velocity (v sin i) | 1.8[7] km/s |
| Age | 9.155±2.199 Gyr |
| Other designations | |
| HD 106515 A: Gaia DR2 3584074380866605440, SAO 138673, LTT 4599, 2MASS J12150658-0715263[9] | |
| HD 106515 B: Gaia DR2 3584074376569429248, SAO 138674, LTT 4598, 2MASS J12150611-0715265[10] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
The A and B stars are both K-type main-sequence stars, both somewhat smaller and cooler than the Sun. The two are gravitationally bound and separated at 310 AU. The binary semimajor axis is 390 AU.[5]
The third star in the visual triple, BD−06°3533, is a physically unrelated background star.[2]
Properties
HD 106515 AB is a wide binary system which was first observed by Jérôme de Lalande in 1795.[2]
The discovery of HD 106515 Ab was announced in a preprint submitted on September 12, 2011.[11] The discovery was made using radial velocity measurements obtained at the CORALIE spectrograph located at La Silla Observatory.[5] Confirmation of the discovery was made by a separate team using the Galileo National Telescope at the Roque de los Muchachos Observatory on the island of La Palma in the Canary Islands, Spain.[12] Initially announced as an exoplanet,[11] astrometric observations in 2021 have found that the true mass is significantly higher than its minimum mass predicted from radial velocity, so it is likely a brown dwarf.[13] A 2022 study found a true mass closer to the minimum mass, but the parameters are less well constrained.[14]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (years) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 18.9+1.5 −1.4 MJ | 4.48±0.050 | 9.927+0.030 −0.032 | 0.571±0.012 | 29.2+2.4 −2.2° | — |