CD-73°375 is a binary star located in the constellation Volans about 820 light years away. The two components, HR 2979 and HR 2980, are separated by two arc-seconds. The pair has a combined apparent magnitude of 6.34. It has a radial velocity of about 13 km/s, which means it drifting away from the Solar System.

CD-73°375
Location of CD-73°375 (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Volans
A
Right ascension 07h 35m 21.656s[1]
Declination −74° 16′ 29.83″[1]
Apparent magnitude (V) 7.08[2]
B
Right ascension 07h 35m 22.036s[3]
Declination −74° 16′ 30.96″[3]
Apparent magnitude (V) 7.02[2]
Characteristics
Evolutionary stage subgiant
Spectral type B9IV + B9IV[4]
Astrometry
A
Radial velocity (Rv)+13.0[5] km/s
Proper motion (μ) RA: −2.527±0.040 mas/yr[1]
Dec.: 21.791±0.033 mas/yr[1]
Parallax (π)3.9430 ± 0.0292 mas[1]
Distance827 ± 6 ly
(254 ± 2 pc)
B
Radial velocity (Rv)+10.8[5] km/s
Proper motion (μ) RA: −3.650±0.032 mas/yr[3]
Dec.: 18.164±0.034 mas/yr[3]
Parallax (π)3.9907 ± 0.0274 mas[3]
Distance817 ± 6 ly
(251 ± 2 pc)
Details
A
Mass3.5[6] M
Radius3.6[7] R
Luminosity582[8] L
Surface gravity (log g)3.96[6] cgs
Temperature13,005[6] K
Metallicity [Fe/H]−0.15[6] dex
Rotational velocity (v sin i)17[8] km/s
B
Mass3.4[6] M
Surface gravity (log g)3.93[6] cgs
Temperature12,640[6] K
Metallicity [Fe/H]−0.15[6] dex
Other designations
CD−73°375, HIP 36914, WDS J07354-7417
A: HD 62153, HR 2979
B: HD 62154, HR 2980
Database references
SIMBADdata
A
B

Properties

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The two stars making up CD-73°375 are both B9 subgiants with almost identical properties. HR 2979 is generally designated as the primary because of its higher mass, although HR 2980 is marginally brighter at magnitude 7.02. They are 1.9 apart and have an assumed orbit of 3,760 years.[9]

Each star has a mass about three and a half times the Sun's and a temperature of about 13,000 K.

References

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  1. ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  2. ^ a b Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (2002-03-01). "The Tycho double star catalogue". Astronomy and Astrophysics. 384: 180–189. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822. ISSN 0004-6361.
  3. ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  4. ^ Houk, Nancy (1975). "Michigan catalogue of two-dimensional spectral types for the HD stars". University of Michigan Catalogue of Two-Dimensional Spectral Types for the Hd Stars. Volume I. Declinations -90_ to -53_Ƒ0. 1. Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan. Bibcode:1975mcts.book.....H.
  5. ^ a b Andersen, J.; Nordstrom, B. (1983). "Radial velocities of bright southern stars. I - 139 B-type HR and FK stars". Astronomy and Astrophysics Supplement Series. 52: 471–482. Bibcode:1983A&AS...52..471A.
  6. ^ a b c d e f g h Anders, F.; Khalatyan, A.; Chiappini, C.; Queiroz, A. B.; Santiago, B. X.; Jordi, C.; Girardi, L.; Brown, A. G. A.; Matijevic, G.; Monari, G.; Cantat-Gaudin, T. (2019-08-01). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy and Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. ISSN 0004-6361.
  7. ^ Stassun, Keivan G.; Oelkers, Ryan J.; Pepper, Joshua; Paegert, Martin; De Lee, Nathan; Torres, Guillermo; Latham, David W.; Charpinet, Stéphane; Dressing, Courtney D.; Huber, Daniel; Kane, Stephen R.; Lépine, Sébastien; Mann, Andrew; Muirhead, Philip S.; Rojas-Ayala, Bárbara; Silvotti, Roberto; Fleming, Scott W.; Levine, Al; Plavchan, Peter; the TESS Target Selection Working Group (2018). "The TESS Input Catalog and Candidate Target List". The Astronomical Journal. 156 (3): 102. arXiv:1706.00495. Bibcode:2018AJ....156..102S. doi:10.3847/1538-3881/aad050. S2CID 73582386.
  8. ^ a b Zorec, J.; Royer, F. (2012-01-01). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691. ISSN 0004-6361.
  9. ^ Tokovinin, Andrei (2018-03-01). "The Updated Multiple Star Catalog". The Astrophysical Journal Supplement Series. 235 (1): 6. arXiv:1712.04750. Bibcode:2018ApJS..235....6T. doi:10.3847/1538-4365/aaa1a5. ISSN 0067-0049. S2CID 119047709.