Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Virgo |
Right ascension | 13h 58m 24.860s [2] |
Declination | −01° 39′ 38.95″ [2] |
Apparent magnitude (V) | 9.60 - 10.56 [3] |
Characteristics | |
Evolutionary stage | Main sequence |
Spectral type | G0 V + G2 V [4] |
B−V color index | 0.650±0.043 [5] |
Variable type | Algol + RS CVn [3] |
Astrometry | |
Radial velocity (Rv) | −22.80±2.7 [6] km/s |
Proper motion (μ) |
RA: 2.672
mas/
yr
[2] Dec.: −5.742 mas/ yr [2] |
Parallax (π) | 6.6834 ± 0.0181 mas [2] |
Distance | 488 ± 1
ly (149.6 ± 0.4 pc) |
Orbit [4] | |
Period (P) | 0.8169 d |
Semi-major axis (a) | ≥1.55 Gm (2.23 R☉) |
Eccentricity (e) | 0.0 |
Inclination (i) | 87.5±0.8 [7]° |
Periastron epoch (T) | 2,431,241.389±1.0 JD |
Argument of periastron (ω) (secondary) | 0.0° |
Semi-amplitude (K1) (primary) | 137.8 km/s |
Semi-amplitude (K2) (secondary) | 135.2 km/s |
Details | |
Component 1 | |
Mass | 1.173±0.006 [7] M☉ |
Radius | 1.22±0.05 [7] R☉ |
Luminosity | 2.19 [8] L☉ |
Surface gravity (log g) | 4.30 [8] cgs |
Temperature | 5,969±11 [9] K |
Metallicity [Fe/H] | +0.1 [8] dex |
Component 2 | |
Mass | 1.046±0.005 [7] M☉ |
Radius | 1.11±0.04 [7] R☉ |
Luminosity | 1.20 [8] L☉ |
Surface gravity (log g) | 4.35 [8] cgs |
Temperature | 5,500 [9] K |
Metallicity [Fe/H] | −0.3 [8] dex |
Other designations | |
Database references | |
SIMBAD | data |
BH Virginis is a binary star system in the equatorial constellation of Virgo. With a typical apparent visual magnitude of 9.6, [3] it is too faint to be visible to the naked eye. Based on parallax measurements, it is located at a distance of approximately 488 light years from the Sun. [2] The system is drifting closer with a net radial velocity of −23 km/s. [6]
This system was determined to be a short period variable star by C. Hoffmeister in 1935. [11] W. Zessewitsch found a period of 19.6 hours for the system in 1944. In 1957, M. Kitamura and associates refined the light curve of this Algol-type eclipsing variable and discovered some irregular fluctuations not explained by the eclipse cycle. [12] R. H. Koch in 1967 reported observing a change in the depth of the primary eclipse. [13] In 1982, M. Hoffmann concluded that both stars are intrinsically variable, indicating this is an RS Canum Venaticorum variable system. [14]
This is a near-contact [15] binary system with a circular orbit having a period of 19.61 hours. [4] The orbital plane is inclined at an angle of 88° to the line of sight from the Earth, [7] allowing both components to eclipse each other once per orbit. During the deep [4] primary eclipse the system decreases in brightness by 0.96 magnitude, while the shallower secondary eclipse decreases the system by 0.64 magnitude. [15] Cyclical oscillations in the orbital period have been observed with two short-term periods of 9.2 and 11.8 years, and a longer-term oscillation of 51.7 years. The short term oscillations may be due to magnetic activity on the stars, while the longer period could be caused by an unseen third body. [16]
Both components of this system are G-type main-sequence stars, with stellar classifications of G0V and G2V, respectively. [4] Evidence of star spots have been found on both stars, but appear to be predominantly on the secondary component. [9] The two stars are somewhat larger and more massive than the Sun. [7]
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Virgo |
Right ascension | 13h 58m 24.860s [2] |
Declination | −01° 39′ 38.95″ [2] |
Apparent magnitude (V) | 9.60 - 10.56 [3] |
Characteristics | |
Evolutionary stage | Main sequence |
Spectral type | G0 V + G2 V [4] |
B−V color index | 0.650±0.043 [5] |
Variable type | Algol + RS CVn [3] |
Astrometry | |
Radial velocity (Rv) | −22.80±2.7 [6] km/s |
Proper motion (μ) |
RA: 2.672
mas/
yr
[2] Dec.: −5.742 mas/ yr [2] |
Parallax (π) | 6.6834 ± 0.0181 mas [2] |
Distance | 488 ± 1
ly (149.6 ± 0.4 pc) |
Orbit [4] | |
Period (P) | 0.8169 d |
Semi-major axis (a) | ≥1.55 Gm (2.23 R☉) |
Eccentricity (e) | 0.0 |
Inclination (i) | 87.5±0.8 [7]° |
Periastron epoch (T) | 2,431,241.389±1.0 JD |
Argument of periastron (ω) (secondary) | 0.0° |
Semi-amplitude (K1) (primary) | 137.8 km/s |
Semi-amplitude (K2) (secondary) | 135.2 km/s |
Details | |
Component 1 | |
Mass | 1.173±0.006 [7] M☉ |
Radius | 1.22±0.05 [7] R☉ |
Luminosity | 2.19 [8] L☉ |
Surface gravity (log g) | 4.30 [8] cgs |
Temperature | 5,969±11 [9] K |
Metallicity [Fe/H] | +0.1 [8] dex |
Component 2 | |
Mass | 1.046±0.005 [7] M☉ |
Radius | 1.11±0.04 [7] R☉ |
Luminosity | 1.20 [8] L☉ |
Surface gravity (log g) | 4.35 [8] cgs |
Temperature | 5,500 [9] K |
Metallicity [Fe/H] | −0.3 [8] dex |
Other designations | |
Database references | |
SIMBAD | data |
BH Virginis is a binary star system in the equatorial constellation of Virgo. With a typical apparent visual magnitude of 9.6, [3] it is too faint to be visible to the naked eye. Based on parallax measurements, it is located at a distance of approximately 488 light years from the Sun. [2] The system is drifting closer with a net radial velocity of −23 km/s. [6]
This system was determined to be a short period variable star by C. Hoffmeister in 1935. [11] W. Zessewitsch found a period of 19.6 hours for the system in 1944. In 1957, M. Kitamura and associates refined the light curve of this Algol-type eclipsing variable and discovered some irregular fluctuations not explained by the eclipse cycle. [12] R. H. Koch in 1967 reported observing a change in the depth of the primary eclipse. [13] In 1982, M. Hoffmann concluded that both stars are intrinsically variable, indicating this is an RS Canum Venaticorum variable system. [14]
This is a near-contact [15] binary system with a circular orbit having a period of 19.61 hours. [4] The orbital plane is inclined at an angle of 88° to the line of sight from the Earth, [7] allowing both components to eclipse each other once per orbit. During the deep [4] primary eclipse the system decreases in brightness by 0.96 magnitude, while the shallower secondary eclipse decreases the system by 0.64 magnitude. [15] Cyclical oscillations in the orbital period have been observed with two short-term periods of 9.2 and 11.8 years, and a longer-term oscillation of 51.7 years. The short term oscillations may be due to magnetic activity on the stars, while the longer period could be caused by an unseen third body. [16]
Both components of this system are G-type main-sequence stars, with stellar classifications of G0V and G2V, respectively. [4] Evidence of star spots have been found on both stars, but appear to be predominantly on the secondary component. [9] The two stars are somewhat larger and more massive than the Sun. [7]