HR 4177

HR 4177
Observation data; Epoch J2000 Equinox J2000
Constellation	Carina
Right ascension	10h 38m 44.99524s
Declination	−59° 10′ 58.7927″
Apparent magnitude (V)	4.77 (4.85 + 7.67)
Characteristics
A
Spectral type	K4.5Ib-II
B−V color index	1.562±0.015
B
Spectral type	B9II/III
B−V color index	0.100±0.020
Astrometry
A
Radial velocity (Rv)	+11.0±0.8 km/s
Proper motion (μ)	RA: −14.284±0.338 mas/yr ; Dec.: +1.117±0.329 mas/yr
Parallax (π)	2.0056 ± 0.1809 mas
Distance	1,600 ± 100 ly ; (500 ± 40 pc)
Absolute magnitude (MV)	−3.66
B
Proper motion (μ)	RA: −14.380±0.089 mas/yr ; Dec.: +0.932±0.085 mas/yr
Parallax (π)	2.1854 ± 0.0512 mas
Distance	1,490 ± 30 ly ; (460 ± 10 pc)
Details
A
Mass	11.9±0.2 M☉
Radius	202+5; −6 R☉
Luminosity	8,478±875 L☉
Temperature	3,900+63; −48 K
Age	16.4±1.0 Myr
B
Temperature	8,316+1,256; −1,389 K
Other designations
	t2 Car, CPD−58°2460, HR 4177, CCDM J10388-5911, WDS J10387-5911
	A: GC 14647, HD 92397, HIP 52102, SAO 238295
	B: GC 14649, HD 92398, HIP 52106, SAO 238297
Database references
SIMBAD	A
	B

HR 4177, also called t² Carinae (t²Car), 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

^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p
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.
- A: 5350588691654540544
- B: 5350588691654545792
^ ^a ^b ^c ^d ^e 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ 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.
^ ^a ^b ^c ^d 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, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
^ ^a ^b "HD 92397". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-13.
^ "HD 92398". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-13.
^ Cantat-Gaudin, T.; et al. (October 2018), "A Gaia DR2 view of the open cluster population in the Milky Way", Astronomy & Astrophysics, 618: 16, arXiv:1805.08726, Bibcode:2018A&A...618A..93C, doi:10.1051/0004-6361/201833476, S2CID 56245426, A93.
^ Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1975mcts.book.....H.
^ Mason, B. D.; et al. (2014), The Washington Visual Double Star Catalog, Bibcode:2001AJ....122.3466M, doi:10.1086/323920, retrieved 2015-07-22

[GaiaDR2-1] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p 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.
A: 5350588691654540544

B: 5350588691654545792

[2] A: 5350588691654540544

[3] B: 5350588691654545792

[Eggleton2008-2] 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.

[Anderson2012-3] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ 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.

[Tetzlaff2011-4] 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, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.

[SimbadA-5] "HD 92397". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-13.

[SimbadB-6] "HD 92398". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-13.

[CantatGaudin2018-7] Cantat-Gaudin, T.; et al. (October 2018), "A Gaia DR2 view of the open cluster population in the Milky Way", Astronomy & Astrophysics, 618: 16, arXiv:1805.08726, Bibcode:2018A&A...618A..93C, doi:10.1051/0004-6361/201833476, S2CID 56245426, A93.

[houk1978-8] Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1975mcts.book.....H.

[WDSC2014-9] Mason, B. D.; et al. (2014), The Washington Visual Double Star Catalog, Bibcode:2001AJ....122.3466M, doi:10.1086/323920, retrieved 2015-07-22

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Observation data Epoch J2000 Equinox J2000
Constellation	Carina
Right ascension	10^h 38^m 44.99524^s^[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 (R_v)	+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 mas^[1]
Distance	1,600 ± 100 ly (500 ± 40 pc)
Absolute magnitude (M_V)	−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 mas^[1]
Distance	1,490 ± 30 ly (460 ± 10 pc)
Details
A
Mass	11.9±0.2^[4] `M`_☉
Radius	202+5 −6^[1] `R`_☉
Luminosity	8,478±875^[1] `L`_☉
Temperature	3,900+63 −48^[1] K
Age	16.4±1.0^[4] Myr
B
Temperature	8,316+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
SIMBAD	A
	B