HD 98800

HD 98800
Observation data
Epoch J2000      Equinox J2000
Constellation Crater
HD 98800 A
Right ascension 11h 22m 05.287s[1]
Declination −24° 46′ 39.78″[1]
Apparent magnitude (V) 9.59[1]
HD 98800 B
Right ascension 11h 22m 05.288s[1]
Declination −24° 46′ 39.05″[1]
Apparent magnitude (V) 10.06[1] (10.4 / 11.5)[2]
Characteristics
HD 98800 A
Spectral type K5V / ?[3]
B−V color index 1.17 / ?[3]
HD 98800 B
Spectral type K7V / M1V[3]
B−V color index 1.37 / 1.41[3]
Variable type T Tau / RS CVn?[4][5][6]
Astrometry
Proper motion (μ) RA: -85.40[7] mas/yr
Dec.: -33.10[7] mas/yr
Parallax (π)22.27 ± 2.31 mas[7]
Distanceapprox. 150 ly
(approx. 45 pc)
Absolute magnitude (MV)6.06 (Aa)[3] 6.91 ± 0.26[8] 8.02 ± 0.27[8]
Orbit[9][10]
PrimaryHD 98800 A
CompanionHD 98800 B
Period (P)246 ± 5 yr
Semi-major axis (a)1.471″
Eccentricity (e)0.5
Inclination (i)88.4 ± 2°
Longitude of the node (Ω)184.8°
Periastron epoch (T)2025
Argument of periastron (ω)
(secondary)		224.6°
Orbit[11]
PrimaryHD 98800 Aa
CompanionHD 98800 Ab
Period (P)264.51±0.02 d
Semi-major axis (a)0.86±0.02 AU
Eccentricity (e)0.4808±0.0008
Inclination (i)135.6±0.1°
Longitude of the node (Ω)170.2±0.1°
Periastron epoch (T)MJD 48742.5±0.8
Argument of periastron (ω)
(primary)		68.7±0.1°
Semi-amplitude (K1)
(primary)		6.7±0.2 km/s
Orbit[11]
PrimaryHD 98800 Ba
CompanionHD 98800 Bb
Period (P)314.86 ± 0.02 d
Semi-major axis (a)1.01±0.01 AU
Eccentricity (e)0.805 ± 0.005
Inclination (i)66.3±0.5°
Longitude of the node (Ω)342.7 ± 0.4°
Periastron epoch (T)MJD 48707.5 ± 0.2
Argument of periastron (ω)
(primary)		104.5 ± 0.3°
Semi-amplitude (K1)
(primary)		24.0 ± 0.3 km/s
Semi-amplitude (K2)
(secondary)		29.9 ± 0.6 km/s
Details
HD 98800 Aa
Mass0.93±0.09[11] M☉
Radius1.75[12] R☉
Surface gravity (log g)4.25[12] cgs
Temperature4500[12] K
Rotational velocity (v sin i)5.0[12] km/s
Age7 ± 5[3] Myr
HD 98800 Ab
Mass0.29±0.02[11] M☉
HD 98800 Ba
Mass0.77 ± 0.04[11] M☉
Radius1.09 ± 0.14[8] R☉
Luminosity0.330 ± 0.075[8] L☉
Surface gravity (log g)4.21 ± 0.12[8] cgs
Temperature4200 ± 150[8] K
Rotational velocity (v sin i)3.0[12] km/s
HD 98800 Bb
Mass0.62 ± 0.02[11] M☉
Radius0.85 ± 0.11[8] R☉
Luminosity0.167 ± 0.038[8] L☉
Surface gravity (log g)4.34 ± 0.12[8] cgs
Temperature4000 ± 150[8] K
Rotational velocity (v sin i)0.0[12] km/s
Other designations
TV Crt, CD−24° 9706, GJ 2084, HD 98800, HIP 55505, SAO 179815, ADS 8141 AB, CCDM J11221-2447AB
Database references
SIMBADHD 98800
HD 98800A
HD 98800B
ARICNSHD 98800A
HD 98800B

HD 98800, also catalogued as TV Crateris (TV Crt), is a quadruple star system in the constellation of Crater (the cup). Parallax measurements made by the Hipparcos spacecraft put it at a distance of about 150 light-years (45 parsecs) away.[7] The system is located within the TW Hydrae association (TWA), and has received the designation TWA 4.[13]

The system consists of HD 98800 A and HD 98800 B each of which contains two stars. In 2007, a debris disk was discovered orbiting HD 98800 B consisting of two rings which indicates there may be an extrasolar planet orbiting within a distance of 1.5 to 2 astronomical units.

  1. ^ a b c d e f Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (2002). "The Tycho double star catalogue". Astronomy and Astrophysics. 384: 180–189. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822.
  2. ^ "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Archived from the original on 2017-08-01. Retrieved 2017-05-07.
  3. ^ a b c d e f Song, Inseok; Caillault, J.-P.; Barrado y Navascués, David; Stauffer, John R.; Randich, Sofia (April 2000), "Ages of Late Spectral Type Vega-like Stars", The Astrophysical Journal, 533 (1): L41–L44, arXiv:astro-ph/0002323, Bibcode:2000ApJ...533L..41S, doi:10.1086/312597, PMID 10727387, S2CID 41394330
  4. ^ Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: B/gcvs. Bibcode:2009yCat....102025S.
  5. ^ Cite error: The named reference Verrier was invoked but never defined (see the help page).
  6. ^ "TV Crt". International Variable Star Index. Retrieved 2020-07-09.
  7. ^ a b c d van Leeuwen, F.; et al. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
  8. ^ a b c d e f g h i j Boden, Andrew F.; Sargent, Anneila I.; Akeson, Rachel L.; Carpenter, John M.; Torres, Guillermo; Latham, David W.; Soderblom, David R.; Nelan, Ed; Franz, Otto G.; Wasserman, Lawrence H. (2005). "Dynamical Masses for Low-Mass Pre–Main-Sequence Stars: A Preliminary Physical Orbit for HD 98800 B". The Astrophysical Journal. 635 (1): 442–451. arXiv:astro-ph/0508331. Bibcode:2005ApJ...635..442B. doi:10.1086/497328. S2CID 15698880.
  9. ^ Cite error: The named reference Kennedy et al was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Tokovinin was invoked but never defined (see the help page).
  11. ^ a b c d e f Zúñiga-Fernández, S.; Olofsson, J.; Bayo, A.; Haubois, X.; Corral-Santana, J. M.; Lopera-Mejía, A.; Ronco, M. P.; Tokovinin, A.; Gallenne, A.; Kennedy, G. M.; Berger, J.-P. (2021). "The HD 98800 quadruple pre-main sequence system" (PDF). Astronomy & Astrophysics. 655: A15. arXiv:2109.02841. doi:10.1051/0004-6361/202141985. S2CID 237431337.
  12. ^ a b c d e f Laskar, Tanmoy; Soderblom, David R.; Valenti, Jeff A.; Stauffer, John R. (2009). "The Metallicity of the Hd 98800 System". The Astrophysical Journal. 698 (1): 660–665. arXiv:0905.1907. Bibcode:2009ApJ...698..660L. doi:10.1088/0004-637X/698/1/660. S2CID 15230160.
  13. ^ Gagné, Jonathan; Faherty, Jacqueline K.; Mamajek, Eric E.; Malo, Lison; Doyon, René; Filippazzo, Joseph C.; Weinberger, Alycia J.; Donaldson, Jessica K.; Lépine, Sébastien; Lafrenière, David; Artigau, Étienne; Burgasser, Adam J.; Looper, Dagny; Boucher, Anne; Beletsky, Yuri; Camnasio, Sara; Brunette, Charles; Arboit, Geneviève (2017). "BANYAN. IX. The Initial Mass Function and Planetary-mass Object Space Density of the TW Hya Association". The Astrophysical Journal Supplement Series. 228 (2): 18. arXiv:1612.02881. Bibcode:2017ApJS..228...18G. doi:10.3847/1538-4365/228/2/18. S2CID 118920136.