V773 Tauri

V773 Tauri

Light curves for V773 Tauri. The upper panel shows the variability as seen by TESS.[1] The lower panel, adapted from Kenworthy et al.,[2] shows the eclipse seen in 2010.
Observation data Epoch J2000      Equinox J2000
Constellation	Taurus
Right ascension	04^h 14^m 12.926^s[3]
Declination	28° 12′ 12.36″[3]
Apparent magnitude (V)	10.59 to 10.95[4]
Characteristics
Spectral type	K3Ve (Li)[5]
Variable type	Orion variable + BY Dra[4]
Astrometry
Proper motion (μ)	RA: 6.540 mas/yr[3] Dec.: −27.792 mas/yr[3]
Parallax (π)	8.3261 ± 0.1313 mas
Distance	433.1 ± 7.5 ly (132.8±2.3 pc)[6]
Orbit[2]
Primary	V773 Tau AB
Companion	V773 Tau C
Period (P)	624+83 −52 yr
Semi-major axis (a)	1,013+93 −74 mas
Eccentricity (e)	0.40+0.04 −0.05
Inclination (i)	97.3±0.6°
Longitude of the node (Ω)	104.6±1.3°
Periastron epoch (T)	1,740+26 −40
Argument of periastron (ω) (secondary)	107.8±4.5°
Orbit[2]
Primary	V773 Tau A
Companion	V773 Tau B
Period (P)	26.50±0.07 yr
Semi-major axis (a)	117.7±0.86 mas
Eccentricity (e)	0.104±0.009
Inclination (i)	69.25±0.40°
Longitude of the node (Ω)	290.54±0.40°
Periastron epoch (T)	2,010.11±0.12
Argument of periastron (ω) (secondary)	266.0±1.5°
Semi-amplitude (K1) (primary)	6.50±0.50[7] km/s
Orbit[6]
Primary	V773 Tau Aa
Companion	V773 Tau Ab
Period (P)	51.1033±0.0018 d
Semi-major axis (a)	2.809±0.033 mas
Eccentricity (e)	0.2713±0.0066
Inclination (i)	68.5±1.6°
Longitude of the node (Ω)	62.4±1.1°
Periastron epoch (T)	53,059.75±0.28 MJD
Argument of periastron (ω) (secondary)	5.6±2.2°
Semi-amplitude (K1) (primary)	35.72±0.46 km/s
Semi-amplitude (K2) (secondary)	42.9±1.3 km/s
Details
Aa
Mass	1.55±0.11[6] M☉
Radius	2.22[8] R☉
Luminosity	2.56[8] L☉
Surface gravity (log g)	3.93[8] cgs
Temperature	4,900[8] K
Age	3±1[2] Myr
Ab
Mass	1.293±0.068[6] M☉
Radius	1.74[8] R☉
Luminosity	1.37[8] L☉
Surface gravity (log g)	4.08[8] cgs
Temperature	4,740[8] K
Other designations
V773 Tau, HD 283447, HIP 19762, WDS J04142+2813A[9]
Database references
SIMBAD	data

V773 Tauri is a young, multiple star system in the central region^[6] of Taurus, an equatorial constellation. This is a T Tauri-type variable star that ranges in apparent visual magnitude from 10.59 down to 10.95,^[4] which is too faint to be viewed with the naked eye. Based on various estimates, the system is located at a distance of approximately 433 light years from the Sun. It lies near the dark cloud Lynds 1495.^[6]

Aa

Period = 51.1 d

Ab

Period = 26.5 yr

B(ab)

Period = 624 yr

C

Hierarchy of orbits

This system was identified as a T Tauri star by A. E. Rydgren and associates in 1974.^[10] Radio emission was detected from this source in 1983.^[11] In 1993, it was discovered to be a double star with an angular separation of about 150 mas: the two components are designated A and B. Component A was found to be a double-lined spectroscopic binary with an orbital period of 51 days. In 2003 a third member of this group was located, component C,^[6] at a separation of 256 mas from component A.

Orbital solutions for the A–B pair provide an unexpectedly high dynamic mass of 2.69±0.67 M_☉ for component B, suggesting it too may be a binary system.^[7] A single star with that much mass would have 17 times the luminosity of the Sun, which is inconsistent with the observed optical luminosity. Photometry of component B suggests it is experiencing extinction from dust along the line of sight. The component is variable in the K band, which is consistent with clumps or clouds of dust in orbit.^[2]

In 2010, an extended eclipse was observed in the V773 Tauri system. This was interpreted as a circumbinary disk of component B passing in front of component A. The eclipse obscured 70% of the emission from component A and lasted 150 days.^[2]

References

1. MAST: Barbara A. Mikulski Archive for Space Telescopes, Space Telescope Science Institute, retrieved 8 December 2021.
2. Kenworthy, M. A.; et al. (October 2022), "Eclipse of the V773 Tau B circumbinary disc", Astronomy & Astrophysics, 666: A61, arXiv:2207.05575, Bibcode:2022A&A...666A..61K, doi:10.1051/0004-6361/202243441, S2CID 250451004, A61.
3. 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. Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
5. Herbig, G. H. (1977), "Radial velocities and spectral types of T Tauri stars", Astrophysical Journal, 214: 747–758, Bibcode:1977ApJ...214..747H, doi:10.1086/155304.
6. Torres, Rosa M.; et al. (March 2012), "VLBA Determination of the Distance to nearby Star-forming Regions. V. Dynamical Mass, Distance, and Radio Structure of V773 Tau A", The Astrophysical Journal, 747 (1): 18, arXiv:1112.0114, Bibcode:2012ApJ...747...18T, doi:10.1088/0004-637X/747/1/18, S2CID 494696, 18.
7. Boden, Andrew F.; et al. (March 2012), "A Surprising Dynamical Mass for V773 Tau B", The Astrophysical Journal, 747 (1): 17, arXiv:1112.1018, Bibcode:2012ApJ...747...17B, doi:10.1088/0004-637X/747/1/17, S2CID 118997621, 17.
8. Boden, Andrew F.; et al. (December 2007), "Dynamical Masses for Pre-Main-Sequence Stars: A Preliminary Physical Orbit for V773 Tau A", The Astrophysical Journal, 670 (2): 1214–1224, arXiv:0706.2376, Bibcode:2007ApJ...670.1214B, doi:10.1086/521296, S2CID 40241514.
9. "HD 283447". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2023-01-22.
10. Rydgren, A. E.; et al. (March 1976), "The nature of the objects of Joy: a study of the T Tauri phenomenon.", Astrophysical Journal Supplement Series, 30: 307–336, Bibcode:1976ApJS...30..307R, doi:10.1086/190364. See notes about HD 283447.
11. Kutner, M. L.; et al. (October 1986), "Detection of 6 CM radio emission from late-type PMS stars with weak chromospheric emission", Astronomical Journal, 92: 895–897, Bibcode:1986AJ.....92..895K, doi:10.1086/114223.

Further reading

• Umemoto, T.; et al. (August 2009), Hagiwara, Yoshiaki; et al. (eds.), "Detection of a Radio Flare at Millimeter-Wavelengths from the X-ray T Tauri Star V773 Tau", Approaching Micro-Arcsecond Resolution with VSOP-2, proceedings of the conference held 3–7 December 2007, at ISAS/JAXA, Sagamihara, Kanagawa, Japan, Astrophysics and Technologies ASP Conference Series, vol. 402, p. 400, Bibcode:2009ASPC..402..400U.
• Massi, M.; et al. (March 2008), "Interacting coronae of two T Tauri stars: first observational evidence for solar-like helmet streamers", Astronomy and Astrophysics, 480 (2): 489–494, arXiv:0712.0718, Bibcode:2008A&A...480..489M, doi:10.1051/0004-6361:20078637, S2CID 11380885.
• Massi, M.; et al. (July 2006), "Synchrotron emission from the T Tauri binary system V773 Tauri A", Astronomy and Astrophysics, 453 (3): 959–964, arXiv:astro-ph/0604124, Bibcode:2006A&A...453..959M, doi:10.1051/0004-6361:20053535, S2CID 14134438.
• Duchêne, G.; et al. (July 2003), "No Fossil Disk in the T Tauri Multiple System V773 Tauri", The Astrophysical Journal, 592 (1): 288–298, arXiv:astro-ph/0303648, Bibcode:2003ApJ...592..288D, doi:10.1086/375624, S2CID 119094313.
• Tamazian, Vakhtang S.; et al. (October 2002), "Preliminary Orbits and System Masses for Five Binary T Tauri Stars", The Astrophysical Journal, 578 (2): 925–934, Bibcode:2002ApJ...578..925T, doi:10.1086/342621, S2CID 123360722.
• Massi, M.; et al. (January 2002), "Periodic radio flaring on the T Tauri star V 773 Tauri", Astronomy and Astrophysics, 382: 152–156, Bibcode:2002A&A...382..152M, doi:10.1051/0004-6361:20011585, S2CID 56413068.
• Tsuboi, Yohko; et al. (August 1998), "ASCA Detection of a Superhot 100 Million K X-Ray Flare on the Weak-Lined T Tauri Star V773 Tauri", The Astrophysical Journal, 503 (2): 894–901, Bibcode:1998ApJ...503..894T, doi:10.1086/306024, S2CID 121483342.
• Skinner, Stephen L.; et al. (September 1997), "ASCA Observations of the Barnard 209 Dark Cloud and an Intense X-Ray Flare on V773 Tauri", The Astrophysical Journal, 486 (2): 886–902, Bibcode:1997ApJ...486..886S, doi:10.1086/304561, hdl:2060/19980076126, S2CID 123108722.
• Skinner, S. L. (May 1996), "Time-Resolved X-ray Spectroscopy of the Weak-lined T Tauri Star V773 Tau", Bulletin of the American Astronomical Society, 28: 884, Bibcode:1996AAS...188.4008S.
• Welty, Alan D. (August 1995), "Discovery of a Pre-Main-Sequence Spectrscopic Binary: V773 Tauri", Astronomical Journal, 110: 776, Bibcode:1995AJ....110..776W, doi:10.1086/117562.