HD 56405 is a star in the southern constellation of Canis Major. It is white in hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.45.[2] To the east of HD 56405 is the open cluster NGC 2360, also known as Caroline's Cluster.[8] The distance to HD 56405, as determined from parallax measurements, is approximately 249 light years. It is drifting further away with a radial velocity (RV) of about +6 km/s.[5] Although classed as a single star,[9] it is to suspected to vary in RV.[10]

HD 56405
Location of HD 56405 (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Canis Major
Right ascension 07h 16m 14.55342s[1]
Declination −15° 35′ 08.4724″
Apparent magnitude (V) 5.45[2]
Characteristics
Spectral type A1V[3]
B−V color index 0.079±0.005[4]
Astrometry
Radial velocity (Rv)+6.30±0.9[5] km/s
Proper motion (μ) RA: -46.118[1] mas/yr
Dec.: -15.488[1] mas/yr
Parallax (π)13.1152 ± 0.1293 mas[1]
Distance249 ± 2 ly
(76.2 ± 0.8 pc)
Absolute magnitude (MV)0.88[4]
Details
Mass2.13[6] M
Luminosity38.86[4] L
Surface gravity (log g)4.14±0.14[6] cgs
Temperature9,562±325[6] K
Rotational velocity (v sin i)149[6] km/s
Age212[6] Myr
Other designations
BD−15°1734, FK5 2561, GC 9657, GJ 9228, HD 56405, HIP 35180, HR 2758, SAO 152641, TYC 5965-363-1[7]
Database references
SIMBADdata

This is an A-type main-sequence star with a stellar classification of A1V.[3] It was classed as a candidate Lambda Boötis star,[11] but as of 2015 this classification has been rejected by astronomers due to the star having an inconsistent UV flux, possible RV variability, and a fairly high rotation rate.[2] The star is about 212 million years old with 2.13 times the mass of the Sun and is spinning with a projected rotational velocity of 149 km/s.[6] It is radiating 39[4] times the luminosity of the Sun from its photosphere at an effective temperature of around 9,562 K.[6]

References edit

  1. ^ a b c d 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.
  2. ^ a b c Murphy, Simon J.; et al. (October 2015). "An Evaluation of the Membership Probability of 212 λ Boo Stars. I. A Catalogue". Publications of the Astronomical Society of Australia. 32: 43. arXiv:1508.03633. Bibcode:2015PASA...32...36M. doi:10.1017/pasa.2015.34. S2CID 59405545. e036.
  3. ^ a b Houk, Nancy; Smith-Moore, M. (1978). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 4. Ann Arbor: Dept. of Astronomy, University of Michigan. Bibcode:1988mcts.book.....H.
  4. ^ a b c d 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. S2CID 119257644.
  5. ^ a b Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
  6. ^ a b c d e f g David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal. 804 (2): 146. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146. S2CID 33401607.
  7. ^ "HD 56405". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-01-06.
  8. ^ Streicher, M. (December 2005). "Deepsky Delights: Caroline Herschel's deepsky discoveries". Monthly Notes of the Astronomical Society of Southern Africa. 64 (11 and 12): 234–236. Bibcode:2005MNSSA..64..234S.
  9. ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
  10. ^ Gerbaldi, M.; et al. (December 2003). "The heterogeneous class of lambda Bootis stars". Astronomy and Astrophysics. 412 (2): 447–464. Bibcode:2003A&A...412..447G. doi:10.1051/0004-6361:20031472.
  11. ^ Renson, P.; et al. (December 1990). "Catalogue of Lambda Bootis Candidates". Bulletin d'Information du Centre de Données Stellaires. 38: 137. Bibcode:1990BICDS..38..137R.