HD 106906

HD 106906

Star map shows star position on the northern edge of the constellation Crux
Observation data
Epoch J2000.0      Equinox ICRS
Constellation Crux
Right ascension 12h 17m 53.191430s
Declination −55° 58′ 31.8904″
Apparent magnitude (V) 7.80
Characteristics
Evolutionary stage pre-main sequence
Spectral type F5 V
B−V color index 0.458±0.003
Astrometry
Radial velocity (Rv)+10.2±1.7 km/s
Proper motion (μ) RA: −39.014 mas/yr
Dec.: −12.872 mas/yr
Parallax (π)9.6774±0.0429 mas
Distance337 ± 1 ly
(103.3 ± 0.5 pc)
Absolute magnitude (MV)+2.99
Details
A
Mass1.35 M☉
Age13±2 Myr
B
Mass1.35 M☉
Age13±2 Myr
Other designations
CD−55°4537, HD 106906, HIP 59960, SAO 239819, 2MASS J12175319-5558319
Database references
SIMBADdata

HD 106906 is a binary star 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. 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. It is a member of the Lower Centaurus–Crux group of the Scorpius–Centaurus OB association of co-moving stars.

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. Their orbital period is less than 100 days.

Planetary system

Edge-on disc of gas and dust present around the binary star system HD 106906

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. 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.

In 2026, a second companion, either a planet or brown dwarf orbiting much closer than HD 106906 b, was found using astrometry. The discovery of such a companion highligths the necessity of revising the orbital evolution of this system.

The HD 106906 planetary system
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(years)		 Eccentricity Inclination
(°)		 Radius
c 3–20 MJ 3–10 — — — —
debris disk 65–550 AU 84.65 ± 0.35° —
b 11 ± 2 MJ ~732 ± 30 AU > 3000 — 64 1.54 +0.04
−0.05 RJ

References

  1. 1 2 3 4 5 6 7 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. XHIP record for this object at VizieR.
  2. 1 2 3 4 5 Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  3. 1 2 3 Rouan, Daniel; Boccaletti, Anthony; Perrot, Clément; Baudoz, Pierre; Mâlin, Mathilde; Lagage, Pierre-Olivier; Waters, Rens; Güdel, Manuel; Henning, Thomas; Vandenbussche, Bart; Absil, Olivier; Barrado, David; Cossou, Christophe; Decin, Leen; Glauser, Adrian M.; Pye, John; Patapis, Polychronis; Whiteford, Niall; Serabyn, Eugene; Choquet, Elodie; Ostlin, Göran; Ray, Tom P.; Wright, Gillian (2025). "MIRI-JWST mid-infrared direct imaging of the debris disk of HD 106906: Structure and mass of the disk". Astronomy and Astrophysics. 698. arXiv:2504.13679. Bibcode:2025A&A...698A.113R. doi:10.1051/0004-6361/202452302.
  4. ↑ Houk, Nancy; Cowley, A. P. (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
  5. 1 2 3 4 5 Rodet, L.; et al. (June 2017), "Origin of the wide-orbit circumbinary giant planet HD 106906. A dynamical scenario and its impact on the disk", Astronomy & Astrophysics, 602: 15, arXiv:1703.01857, Bibcode:2017A&A...602A..12R, doi:10.1051/0004-6361/201630269, S2CID 119424481, A12.
  6. ↑ "HD 106906". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-01-30.
  7. 1 2 Lagrange, A. -M.; et al. (February 2016), "A narrow, edge-on disk resolved around HD 106906 with SPHERE", Astronomy & Astrophysics, 586: 6, arXiv:1510.02511, Bibcode:2016A&A...586L...8L, doi:10.1051/0004-6361/201527264, S2CID 4812512, L8.
  8. ↑ Bryan, Marta L.; Chiang, Eugene; Morley, Caroline V.; Mace, Gregory N.; Bowler, Brendan P. (2021), "Obliquity Constraints on the Planetary-mass Companion HD 106906 b", The Astronomical Journal, 162 (5): 217, arXiv:2108.13437, Bibcode:2021AJ....162..217B, doi:10.3847/1538-3881/ac1bb1, S2CID 237364108
  9. 1 2 3 Lagrange, A.-M.; Toucheboeuf, S.; Kiefer, F.; Rubini, P.; Milli, J.; Matrà, L.; Beust, H.; Perrot, C.; Mâlin, M.; Boccaletti, A.; Wilkinson, C.; Delorme, P. (2026-08-10). "Searching for substellar companion candidates with Gaia. IV. New planetary-mass companions found in debris disks". Astronomy & Astrophysics. doi:10.1051/0004-6361/202557917. ISSN 0004-6361.
  10. ↑ Kalas, Paul G.; et al. (2015), "Direct Imaging of an Asymmetric Debris Disk in the Hd 106906 Planetary System", The Astrophysical Journal, 814 (1): 32, arXiv:1510.02747, Bibcode:2015ApJ...814...32K, doi:10.1088/0004-637X/814/1/32, S2CID 59575201
  11. ↑ Bryan, Marta L.; Ginzburg, Sivan; Chiang, Eugene; Morley, Caroline; Bowler, Brendan P.; Xuan, Jerry W.; Knutson, Heather A. (2020-12-01). "As the Worlds Turn: Constraining Spin Evolution in the Planetary-mass Regime". The Astrophysical Journal. 905 (1): 37. arXiv:2010.07315. Bibcode:2020ApJ...905...37B. doi:10.3847/1538-4357/abc0ef. ISSN 0004-637X.