HD 40873

HD 40873

Location of HD 40873 (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Auriga
Right ascension	06^h 04^m 29.11992^s[1]
Declination	+51° 34′ 24.1921″[1]
Apparent magnitude (V)	6.45[2]
Characteristics
Spectral type	A7 V[3] or A7 III[4]
U−B color index	+0.16[2]
B−V color index	+0.196±0.007[5]
Astrometry
Radial velocity (Rv)	19.6±2.9[5] km/s
Proper motion (μ)	RA: +1.850[1] mas/yr Dec.: −41.692[1] mas/yr
Parallax (π)	7.1678 ± 0.0962 mas[1]
Distance	455 ± 6 ly (140 ± 2 pc)
Absolute magnitude (MV)	0.76[5]
Details
Luminosity	38[6] L☉
Temperature	7,753[6] K
Rotational velocity (v sin i)	134[7] km/s
Other designations
35 Camelopardalis, NSV 2804, BD+51°1146, FK5 2463, HD 40873, HIP 28765, HR 2123, SAO 25548
Database references
SIMBAD	data

HD 40873 is a star in the northern constellation of Auriga, a few degrees to the south of Delta Aurigae. Located around 455 light-years distant,^[1] it shines with a luminosity approximately 38 times that of the Sun and has an effective temperature of 7,753 K.^[6] It is a suspected variable star^[2] and has a fairly rapid rotation rate, showing a projected rotational velocity of 134 km/s.^[7] Eggen (1985) suggested it is a probable member of the Hyades Supercluster.^[8]

Samuel Molyneux named this star Telescopica in Auriga.^[9] Flamsteed catalogued it as 35 Camelopardalis Heveliana, which is the name James Bradley continued to use, although it is within the borders of the modern constellation Auriga.^[10] Francis Baily reclassified it to Auriga as star 1924 in the British Association's 1845 Catalogue of 8377 Stars.^[11]

HD 40873 is considered to be an Am star, a chemically peculiar star with unusually strong absorption lines of metals.^[12] It has been given a spectral type of kA5mA7IV,^[13] although other catalogues have given more normal classifications such as A7 V or A7 III.^[3][4]

Components

HD 40873 has a 9th magnitude class A5 companion about half an arc-minute away. It is designated as SAO 25549.^[14] The companion is itself a pair of stars, each of similar brightness, separated by 0.6".^[15]

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. Danziger, I. J.; Dickens, R. J. (July 1967). "Spectrophotometry of New Short-Period Variable Stars". Astrophysical Journal. 149: 55. Bibcode:1967ApJ...149...55D. doi:10.1086/149231.
3. Abt, Helmut A.; Morrell, Nidia I. (1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". Astrophysical Journal Supplement. 99: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182.
4. Cowley, A.; et al. (April 1969). "A study of the bright A stars. I. A catalogue of spectral classifications". Astronomical Journal. 74: 375–406. Bibcode:1969AJ.....74..375C. doi:10.1086/110819.
5. 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.
6. 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.
7. Royer, F.; et al. (October 2002). "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i". Astronomy and Astrophysics. 393 (3): 897–911. arXiv:astro-ph/0205255. Bibcode:2002A&A...393..897R. doi:10.1051/0004-6361:20020943. S2CID 14070763.
8. Eggen, O. J. (June 1985). "A systematic search for members of the Hyades Supercluster. IV - The metallic-line stars and ultrashort-period Cepheids". Astronomical Journal. 90: 1046−1059. Bibcode:1985AJ.....90.1046E. doi:10.1086/113812.
9. Bradley, James; Rigaud, Stephen Peter (1832). Miscellaneous works and correspondence of the Rev. James Bradley, D.D., F.R.S. Oxford University Press. p. 212.
10. Wagman, M. (1987). "Flamsteed's Missing Stars". Journal for the History of Astronomy. 18 (3): 209–223. Bibcode:1987JHA....18..209W. doi:10.1177/002182868701800305. S2CID 118445625.
11. British Association for the Advancement of Science; Francis Baily (1845). The Catalogue of Stars of the British Association for the Advancement of Science: Containing the Mean Right Ascensions and North Polar Distances of Eight Thousand Three Hundred and Seventy-seven Fixed Stars, Reduced to January 1, 1850: Together with Their Annual Precessions, Secular Variations and Proper Motions, as Well as the Logarithmic Constants for Computing Precession, Aberration and Nutation. With a Preface Explanatory of Their Construction and Application. R. and J. E. Taylor. pp. 2–.
12. Renson, P.; Manfroid, J. (2009). "Catalogue of Ap, HGMN and Am stars". Astronomy and Astrophysics. 498 (3): 961. Bibcode:2009A&A...498..961R. doi:10.1051/0004-6361/200810788.
13. Gray, R. O.; Garrison, R. F. (1989). "The Late A-Type Stars: Refined MK Classification, Confrontation with Stroemgren Photometry, and the Effects of Rotation". The Astrophysical Journal Supplement Series. 70: 623. Bibcode:1989ApJS...70..623G. doi:10.1086/191349.
14. "CCDM J06045+5135BC". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 8 February 2018.
15. Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.