HD 106906
Binary star in the constellation Crux
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HD 106906 is a binary star[7] system in the southern constellation of Crux. It is too faint to be visible to the naked eye, having a combined apparent visual magnitude of 7.80.[1] The distance to this system is approximately 337 light years based on parallax, and it is receding from the Sun with a radial velocity of +10 km/s.[1] It is a member of the Lower Centaurus–Crux group of the Scorpius–Centaurus OB association of co-moving stars.[5]
Star map shows star position on the northern edge of the constellation Crux | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Crux[1] |
| Right ascension | 12h 17m 53.191430s[2] |
| Declination | −55° 58′ 31.8904″[2] |
| Apparent magnitude (V) | 7.80[1] |
| Characteristics | |
| Evolutionary stage | pre-main sequence[3] |
| Spectral type | F5 V[4] |
| B−V color index | 0.458±0.003[1] |
| Astrometry | |
| Radial velocity (Rv) | +10.2±1.7[1] km/s |
| Proper motion (μ) | RA: −39.014[2] mas/yr Dec.: −12.872[2] mas/yr |
| Parallax (π) | 9.6774±0.0429 mas[2] |
| Distance | 337 ± 1 ly (103.3 ± 0.5 pc) |
| Absolute magnitude (MV) | +2.99[1] |
| Details | |
| A | |
| Mass | 1.35[3] M☉ |
| Age | 13±2[5] Myr |
| B | |
| Mass | 1.35[3] M☉ |
| Age | 13±2[5] Myr |
| Other designations | |
| CD−55°4537, HD 106906, HIP 59960, SAO 239819, 2MASS J12175319-5558319[6] | |
| Database references | |
| SIMBAD | data |
This is a double-lined spectroscopic binary system consisting of two F-type main-sequence stars with similar masses and a matching stellar classification of F5 V.[7] Their orbital period is less than 100 days.[5]
Planetary system
A distant circumbinary planet—HD 106906 b—is orbiting the pair at a projected separation of 732±30 AU with a period of at least 3,000 years. An infrared excess around the binary is coming from a circumstellar debris disk that is being viewed edge-on. This has a pronounced asymmetrical shape, extending 120 AU on the east side and out to 550 AU to the west.[5] Planetary orbit is inclined to the debris disk by 39+20
−15 degrees, and planet itself is visible nearly pole-on, having a large axial tilt.[8]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| debris disk | 65–550 AU | 84.65 ± 0.35° | — | |||
| b | 11 ± 2 MJ | ~732 ± 30 AU | > 3000 | — | 64° | 1.54 +0.04 −0.05[10] RJ |