Astronomy:HR 4177

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Short description: Star in the constellation Carina
HR 4177
Observation data
Equinox J2000.0]] (ICRS)
Constellation Carina
Right ascension  10h 38m 44.99524s[1]
Declination −59° 10′ 58.7927″[1]
Apparent magnitude (V) 4.77 (4.85 + 7.67)[2]
Characteristics
A
Spectral type K4.5Ib-II[3]
B−V color index 1.562±0.015[3]
B
Spectral type B9II/III[3]
B−V color index 0.100±0.020[3]
Astrometry
A
Radial velocity (Rv)+11.0±0.8[3] km/s
Proper motion (μ) RA: −14.284±0.338[1] mas/yr
Dec.: +1.117±0.329[1] mas/yr
Parallax (π)2.0056 ± 0.1809[1] mas
Distance1,600 ± 100 ly
(500 ± 40 pc)
Absolute magnitude (MV)−3.66[3]
B
Proper motion (μ) RA: −14.380±0.089[1] mas/yr
Dec.: +0.932±0.085[1] mas/yr
Parallax (π)2.1854 ± 0.0512[1] mas
Distance1,490 ± 30 ly
(460 ± 10 pc)
Details
A
Mass11.9±0.2[4] M
Radius202+5
−6
[1] R
Luminosity8,478±875[1] L
Temperature3,900+63
−48
[1] K
Age16.4±1.0[4] Myr
B
Temperature8,316+1,256
−1,389
[1] K
Other designations
t2 Car, CPD−58°2460, HR 4177, CCDM J10388-5911, WDS J10387-5911[5]
A: GC 14647, HD 92397, HIP 52102, SAO 238295[5]
B: GC 14649, HD 92398, HIP 52106, SAO 238297[6]
Database references
SIMBADA
B

HR 4177, also called t² Carinae (t² Car), is a double star[2] in the southern constellation of Carina. It is faintly visible to the naked eye with a combined apparent visual magnitude of +4.77.[2] The two components are HD 92397 and HD 92398. The primary component is located at a distance of approximately 1,600 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +11 km/s.[3] It has a peculiar velocity of 24.3+9.9
−16.1
 km/s
and may be a runaway star.[4] The star is a member of the BH 99 cluster.[7]

The magnitude 4.85[2] primary, component A, is a massive K-type supergiant or bright giant with a stellar classification of K4.5Ib-II.[3] Houk (1978) instead listed it with a class of K4/5III: but with some uncertainty about the classification.[8] It has 12[4] times the mass of the Sun and has expanded to 202[1] times the Sun's radius. The star is radiating 8,478[1] times the luminosity of the Sun from its bloated photosphere at an effective temperature of 3,900 K.[1]

The magnitude 7.48 companion star, component B, was discovered by J. Dunlop in 1829. As of 2015, it was located at an angular separation of 14.60 along a position angle of 21°, relative to the primary.[9] It is a B-type giant/bright giant star with a class of B9II/III.[3] The pair show a common proper motion and roughly similar parallax measurements,[1] but it remains unclear whether they form a gravitationally-bound pair.[2]

References

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G. 
  2. 2.0 2.1 2.2 2.3 2.4 Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  4. 4.0 4.1 4.2 4.3 Tetzlaff, N. et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190–200, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode2011MNRAS.410..190T. 
  5. 5.0 5.1 "HD 92397". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+92397. 
  6. "HD 92398". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+92398. 
  7. Cantat-Gaudin, T. et al. (October 2018), "A Gaia DR2 view of the open cluster population in the Milky Way", Astronomy & Astrophysics 618: 16, doi:10.1051/0004-6361/201833476, A93, Bibcode2018A&A...618A..93C. 
  8. Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 1, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode1975mcts.book.....H. 
  9. Mason, B. D. et al. (2014), The Washington Visual Double Star Catalog, doi:10.1086/323920, Bibcode2001AJ....122.3466M, http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds, retrieved 2015-07-22 

Coordinates: Sky map 10h 38m 45.1s, −59° 10′ 59″