Astronomy:GI Tauri and GK Tauri
Coordinates: 
04h 33m 34.5627s, +24° 21′ 05.8545″
| Observation data {{#ifeq:J2000|J2000.0 (ICRS)|Epoch J2000.0 Equinox J2000.0 (ICRS)| Epoch J2000 [[Astronomy:Equinox (celestial coordinates)|Equinox J2000}} | |
|---|---|
| Constellation | Taurus |
| GK Tauri | |
| Right ascension | 04h 33m 34.5627s[2] |
| Declination | +24° 21′ 05.8545″[2] |
| Apparent magnitude (V) | 15.10 |
| GI Tauri | |
| Right ascension | 04h 33m 34.0609s[3] |
| Declination | +24° 21′ 17.0674″[3] |
| Apparent magnitude (V) | |
| Characteristics | |
| GK Tauri | |
| Evolutionary stage | pre-main-sequence star |
| Spectral type | K7[4] |
| Apparent magnitude (G) | 11.990[2] |
| Variable type | T Tau |
| GI Tauri | |
| Apparent magnitude (G) | 12.608[3] |
| Astrometry | |
| GK Tauri | |
| Proper motion (μ) | RA: 7.46±0.02[2] mas/yr Dec.: −20.510±0.017[2] mas/yr |
| Parallax (π) | 7.7433 ± 0.0185[2] mas |
| Distance | 421 ± 1 ly (129.1 ± 0.3 pc) |
| GI Tauri | |
| Proper motion (μ) | RA: 5.76±0.02 mas/yr Dec.: −20.642±0.019 mas/yr |
| Parallax (π) | 7.7258 ± 0.0198[3] mas |
| Distance | 422 ± 1 ly (129.4 ± 0.3 pc) |
| Position (relative to GK Tauri)[5] | |
| Component | GI Tauri |
| Angular distance | 13.15797±0.00005″ |
| Position angle | 328.4399±0.0002° |
| Observed separation (projected) | 1700 AU |
| Details[5] | |
| GK Tauri | |
| Mass | 0.79±0.07 M☉ |
| Luminosity | 0.80[6] L☉ |
| Temperature | 4007[6] K |
| Age | 2±1 Myr |
| GI Tauri | |
| Mass | 0.53+0.09−0.11 M☉ |
| Luminosity | 0.49[6] L☉ |
| Temperature | 3792[6] K |
| Age | 2±1 Myr |
| Other designations | |
| GK Tauri: Gaia EDR3 147790206908395776, 2MASS J04333456+2421058, GSC 01829-00040 | |
| GI Tauri: Gaia EDR3 147790000749072768, 2MASS J04333405+2421170, GSC 01829-00082 | |
| Database references | |
| SIMBAD | data |
GK Tauri is a young T Tauri-type pre-main sequence star in the constellation of Taurus about 421 light years away, belonging to the Taurus Molecular Cloud.
System
The stars GK Tauri and GI Tauri form a wide binary system, with the projected separation between components being 1700 AU. The secondary component's orbit is not very eccentric, with a periastron of at least 890 AU.[5]
GK Tauri was originally believed to have a close stellar companion WDS J04336+2421Ab.[7] However, it was found to be an unrelated background star according to Gaia data.[8]
Properties
Both members of the binary system are medium-mass objects still contracting towards the main sequence and accreting mass, with the primary GK Tauri being close to entering the main sequence.[4][5]
Protoplanetary system
Both stars are surrounded by compact protoplanetary disks, although the reason for the small disk sizes is not clear.[5] GK Tauri's spectrum indicates a possible gap in the protoplanetary disk and a planet orbiting within the gap, with a semimajor axis of 2.4+1.5−1.0 AU.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| protoplanetary disk | 0–19 AU | 40.2+5.9−6.2° | — | |||
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| protoplanetary disk | 0–25 AU | 43.8±1.1° | — | |||
References
- ↑ Bouvier, J.; Cabrit, S.; Fernandez, M.; Martin, E. L.; Matthews, J. M. (May 1993). "COYOTES I : the photometric variability and rotational evolution of T Tauri stars". Astronomy and Astrophysics 272: 176–206. Bibcode: 1993A&A...272..176B. https://ui.adsabs.harvard.edu/abs/1993A&A...272..176B. Retrieved 31 March 2022.
- ↑ 2.0 2.1 2.2 2.3 2.4 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
- ↑ 3.0 3.1 3.2 3.3 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
- ↑ 4.0 4.1 4.2 Marsh, Kenneth A.; Mahoney, Michael J. (1993), "Do the Spectral Energy Distributions of GK Tauri and HK Tauri Indicate the Presence of Planetary Companions?", The Astrophysical Journal 405: L71, doi:10.1086/186768, Bibcode: 1993ApJ...405L..71M
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 Pearce, Logan A.; Kraus, Adam L.; Dupuy, Trent J.; Mann, Andrew W.; Newton, Elisabeth R.; Tofflemire, Benjamin M.; Vanderburg, Andrew (2020), "Orbital Parameter Determination for Wide Stellar Binary Systems in the Age of Gaia", The Astrophysical Journal 894 (2): 115, doi:10.3847/1538-4357/ab8389, Bibcode: 2020ApJ...894..115P
- ↑ 6.0 6.1 6.2 6.3 Braun, Teresa A. M.; Yen, Hsi-Wei; Koch, Patrick M.; Manara, Carlo F.; Miotello, Anna; Testi, Leonardo (2021), "Dynamical Stellar Masses of Pre-main-sequence Stars in Lupus and Taurus Obtained with ALMA Surveys in Comparison with Stellar Evolutionary Models", The Astrophysical Journal 908 (1): 46, doi:10.3847/1538-4357/abd24f, Bibcode: 2021ApJ...908...46B
- ↑ "V* GK Tau". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=V%2A+GK+Tau.
- ↑ Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
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