HD 37519

HD 37519 or Andrew's Star is a star in the northern constellation Auriga. It has a blue-white hue and is dimly visible to the naked eye with an apparent visual magnitude of 6.04.^[2] The distance to HD 37519 is approximately 810 light years based on parallax, but it is drifting closer with a radial velocity of −10 km/s.^[5]

HD 37519

Observation data Epoch J2000      Equinox J2000
Constellation	Auriga
Right ascension	05h 40m 35.90737s[1]
Declination	+31° 21′ 29.5262″[1]
Apparent magnitude (V)	6.04[2]
Characteristics
Spectral type	B9.5III-IV(p)? (Hg?)[3]
U−B color index	−0.21[2]
B−V color index	+0.05[2]
Variable type	suspected[4]
Astrometry
Radial velocity (Rv)	−10.2±3.4[5] km/s
Proper motion (μ)	RA: −5.051[1] mas/yr Dec.: −8.187[1] mas/yr
Parallax (π)	4.0335 ± 0.1112 mas[1]
Distance	810 ± 20 ly (248 ± 7 pc)
Absolute magnitude (MV)	−0.43[6]
Details
Radius	3.0[7] R☉
Luminosity	110[8] L☉
Temperature	8,289[8] K
Rotational velocity (v sin i)	195[9] km/s
Age	375[6] Myr
Other designations
NSV 2537, BD+31°1048, FK5 2425, HD 37519, HIP 26712, HR 1938, SAO 58319[10]
Database references
SIMBAD	data

Cowley in 1972 found a stellar classification of B9.5III-IV(p)? (Hg?) for this star,^[3] suggesting it is an evolved B-type star and a suspected chemically peculiar star of the mercury-manganese type.^[11] It is estimated to be 375 million years old and with a high rate of spin, showing a projected rotational velocity of 195 km/s.^[9] In March 1964, a suspected flare of HD 37519 was detected that increased the star's brightness by about three magnitudes. Smaller variations of up to two magnitudes were detected a few days later,^[12] suggesting there might be a flare star companion. However, follow-up observations failed to confirm the variability.^[13] The star is radiating 110^[8] times the luminosity of the Sun from its photosphere at an effective temperature of 8,289 km/s.^[8]

References

1. 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. Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
3. Cowley, A. (November 1972), "Spectral classification of the bright B8 stars", Astronomical Journal, 77: 750–755, Bibcode:1972AJ.....77..750C, doi:10.1086/111348.
4. Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
5. Gontcharov, G. A. (November 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. Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters, 38 (11): 694–706, arXiv:1606.09028, Bibcode:2012AstL...38..694G, doi:10.1134/S1063773712110035, S2CID 119108982.
7. Pasinetti Fracassini, L. E.; et al. (2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy & Astrophysics, 367 (2): 521–24, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
8. McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
9. Abt, Helmut A.; et al. (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode:2002ApJ...573..359A, doi:10.1086/340590.
10. "HD 36780". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-12-28.
11. Renson, P.; Manfroid, J. (May 2009), "Catalogue of Ap, HgMn and Am stars", Astronomy and Astrophysics, 498 (3): 961–966, Bibcode:2009A&A...498..961R, doi:10.1051/0004-6361/200810788.
12. Mammano, A. (May 1966), "Spectrum of the Early-Type Flare Star BD +13 1048", Information Bulletin on Variable Stars, 134: 1, Bibcode:1966IBVS..134....1M.
13. Andrews, A. D. (July 1996), "A Re-Examination of the Suspected Early-Type Flare Star BD+31 1048 (bs 1938) in Auriga: a Skeleton from the Cupboard", Irish Astronomical Journal, 23 (2): 189, Bibcode:1996IrAJ...23..189A.

External links

• HR 1938
• Image HD 37519