Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Taurus |
Right ascension | 03h 48m 13.436s [2] |
Declination | +22° 18′ 50.92″ [2] |
Apparent magnitude (V) | 10.5 (-11.03) [3] |
Characteristics | |
Spectral type | G2 [4] |
Variable type | W UMa [3] |
Astrometry | |
Radial velocity (Rv) | 71.95±1.22 [5] km/s |
Proper motion (μ) |
RA: +69.758
mas/
yr
[2] Dec.: −30.628 mas/ yr [2] |
Parallax (π) | 4.4694 ± 0.0171 mas [2] |
Distance | 730 ± 3
ly (223.7 ± 0.9 pc) |
Orbit [6] | |
Period (P) | 0.341348 d |
Semi-major axis (a) | 2.48±0.03 R☉ [7] |
Eccentricity (e) | 0.00 |
Periastron epoch (T) | 2,451,183.9 HJD |
Semi-amplitude (K1) (primary) | 112.41±1.43 km/s |
Semi-amplitude (K2) (secondary) | 254.38±2.42 km/s |
Details | |
Primary | |
Mass | 1.22±0.04 [7] M☉ |
Radius | 1.14±0.01 [7] R☉ |
Luminosity | 1.32±0.03 [7] L☉ |
Temperature | 5,800±100 [7] K |
Secondary | |
Mass | 0.54±0.02 [7] M☉ |
Radius | 0.79±0.01 [7] R☉ |
Luminosity | 0.63±0.02 [7] L☉ |
Other designations | |
Database references | |
SIMBAD | data |
EQ Tauri is a triple star system in the equatorial constellation of Taurus that includes a contact eclipsing binary. The system is too faint to be viewed with the naked eye, having a baseline apparent visual magnitude of 10.5. [3] During the primary eclipse, the brightness of the system drops to magnitude 11.03, then to 10.97 during the secondary minimum. [3] The secondary eclipse is total. [7] Based on parallax measurements, it is located at a distance of approximately 730 light years from the Sun. [2]
The star HV 6189 was identified as a short-period variable by H. Shapley and E. M. Hughes in 1940, [9] then was more closely studied by Soviet astronomer V. P. Tsesevich in 1954. [6] It was determined to be a W UMa-type variable and was noted for being located in the region of the Pleiades open cluster. [10] An analysis of data from Tsesevich and subsequent observations by B. S. Whitney in 1972 suggested that the period is variable. His observations from Konkoly Observatory showed a period of 8.19 h. [11] W. R. Benbow and R. L. Mutel built a light curve of the eclipsing variable in 1995 that displayed evidence of an active region on the stellar surface. [12] Orbital period changes continued to be observed, and in 2002 T. Pribulla and M. Vanko suggested it is caused by a third body in the system. They modeled it as a low mass red dwarf with an orbital period of 50.2 years. [13]
This is a shallow contact binary system, [7] belonging to sub-type A of the W Ursae Majoris class. [3] It has an orbital period of 8.1924 hours [6] and a semimajor axis of 2.48 times the radius of the Sun. The orbit shows a cyclical change with a period of 22.7 years and an amplitude of 0.0058 days. A transit-like event was observed in 2010. [7] The more massive component is a solar-type star with a deep convection zone that appears magnetically active with a significant coverage of star spots. [4]
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Taurus |
Right ascension | 03h 48m 13.436s [2] |
Declination | +22° 18′ 50.92″ [2] |
Apparent magnitude (V) | 10.5 (-11.03) [3] |
Characteristics | |
Spectral type | G2 [4] |
Variable type | W UMa [3] |
Astrometry | |
Radial velocity (Rv) | 71.95±1.22 [5] km/s |
Proper motion (μ) |
RA: +69.758
mas/
yr
[2] Dec.: −30.628 mas/ yr [2] |
Parallax (π) | 4.4694 ± 0.0171 mas [2] |
Distance | 730 ± 3
ly (223.7 ± 0.9 pc) |
Orbit [6] | |
Period (P) | 0.341348 d |
Semi-major axis (a) | 2.48±0.03 R☉ [7] |
Eccentricity (e) | 0.00 |
Periastron epoch (T) | 2,451,183.9 HJD |
Semi-amplitude (K1) (primary) | 112.41±1.43 km/s |
Semi-amplitude (K2) (secondary) | 254.38±2.42 km/s |
Details | |
Primary | |
Mass | 1.22±0.04 [7] M☉ |
Radius | 1.14±0.01 [7] R☉ |
Luminosity | 1.32±0.03 [7] L☉ |
Temperature | 5,800±100 [7] K |
Secondary | |
Mass | 0.54±0.02 [7] M☉ |
Radius | 0.79±0.01 [7] R☉ |
Luminosity | 0.63±0.02 [7] L☉ |
Other designations | |
Database references | |
SIMBAD | data |
EQ Tauri is a triple star system in the equatorial constellation of Taurus that includes a contact eclipsing binary. The system is too faint to be viewed with the naked eye, having a baseline apparent visual magnitude of 10.5. [3] During the primary eclipse, the brightness of the system drops to magnitude 11.03, then to 10.97 during the secondary minimum. [3] The secondary eclipse is total. [7] Based on parallax measurements, it is located at a distance of approximately 730 light years from the Sun. [2]
The star HV 6189 was identified as a short-period variable by H. Shapley and E. M. Hughes in 1940, [9] then was more closely studied by Soviet astronomer V. P. Tsesevich in 1954. [6] It was determined to be a W UMa-type variable and was noted for being located in the region of the Pleiades open cluster. [10] An analysis of data from Tsesevich and subsequent observations by B. S. Whitney in 1972 suggested that the period is variable. His observations from Konkoly Observatory showed a period of 8.19 h. [11] W. R. Benbow and R. L. Mutel built a light curve of the eclipsing variable in 1995 that displayed evidence of an active region on the stellar surface. [12] Orbital period changes continued to be observed, and in 2002 T. Pribulla and M. Vanko suggested it is caused by a third body in the system. They modeled it as a low mass red dwarf with an orbital period of 50.2 years. [13]
This is a shallow contact binary system, [7] belonging to sub-type A of the W Ursae Majoris class. [3] It has an orbital period of 8.1924 hours [6] and a semimajor axis of 2.48 times the radius of the Sun. The orbit shows a cyclical change with a period of 22.7 years and an amplitude of 0.0058 days. A transit-like event was observed in 2010. [7] The more massive component is a solar-type star with a deep convection zone that appears magnetically active with a significant coverage of star spots. [4]