Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Perseus |
Right ascension | 01h 51m 59.32008s [1] |
Declination | +55° 08′ 50.5837″ [1] |
Apparent magnitude (V) | 5.49 - 5.74 - 5.85 [2] |
Characteristics | |
Spectral type | B1.5V [2] |
Variable type | eclipsing binary [3] |
Astrometry | |
Proper motion (μ) |
RA: 12.716(74)
[1]
mas/
yr Dec.: −8.410(79) [1] mas/ yr |
Parallax (π) | 2.6944 ± 0.0888 mas [1] |
Distance | 1,210 ± 40
ly (370 ± 10 pc) |
Absolute magnitude (MV) | −1.37/−1.77 [4] |
Orbit [4] | |
Primary | 1 Persei A |
Companion | 1 Persei B |
Period (P) | 25.935951±0.000003 d |
Eccentricity (e) | 0.3768±0.0014 |
Inclination (i) | 88.048±0.002° |
Periastron epoch (T) | 2443563.466±0.005 HJD |
Argument of periastron (ω) (secondary) | 109.83±0.10° |
Semi-amplitude (K1) (primary) | 97.4±0.1 km/s |
Semi-amplitude (K2) (secondary) | 91.2±0.1 km/s |
Details [4] | |
Primary | |
Mass | 6.95 M☉ |
Radius | 3.29 R☉ |
Luminosity | 2,188 L☉ |
Surface gravity (log g) | 4.25 cgs |
Temperature | 21,500 K |
Rotation | 1.45 days |
Rotational velocity (v sin i) | 115 km/s |
Secondary | |
Mass | 7.42 M☉ |
Radius | 3.86 R☉ |
Luminosity | 3,311 L☉ |
Surface gravity (log g) | 4.14 cgs |
Temperature | 22,000 K |
Rotation | 1.40 days |
Rotational velocity (v sin i) | 140 km/s |
Other designations | |
Database references | |
SIMBAD | data |
1 Persei (1 Per) is an eclipsing binary [3] star in the constellation Perseus. Its uneclipsed apparent magnitude is 5.49. The binary star consists of two B2 type main-sequence stars in a 25.9 day eccentric orbit. [5] The stars are surrounded by a faint cloud of gas visible in mid-infrared, although whether they are the origin of the gas or simply passing through it is unclear.
The possible eclipsing binary nature of 1 Persei was first noticed by Donald Kurtz in 1977 when it was used as a comparison star to test for photometric variability of HD 11408. [6] In 1979 French amateur observers succeeded in determining an orbital period of 25.9 days. [7] During the primary eclipse, the brightness drops to magnitude 5.85. In the secondary eclipses, the brightness drops to magnitude 5.74. The eclipses each last for approximately 25 hours. [2]
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Perseus |
Right ascension | 01h 51m 59.32008s [1] |
Declination | +55° 08′ 50.5837″ [1] |
Apparent magnitude (V) | 5.49 - 5.74 - 5.85 [2] |
Characteristics | |
Spectral type | B1.5V [2] |
Variable type | eclipsing binary [3] |
Astrometry | |
Proper motion (μ) |
RA: 12.716(74)
[1]
mas/
yr Dec.: −8.410(79) [1] mas/ yr |
Parallax (π) | 2.6944 ± 0.0888 mas [1] |
Distance | 1,210 ± 40
ly (370 ± 10 pc) |
Absolute magnitude (MV) | −1.37/−1.77 [4] |
Orbit [4] | |
Primary | 1 Persei A |
Companion | 1 Persei B |
Period (P) | 25.935951±0.000003 d |
Eccentricity (e) | 0.3768±0.0014 |
Inclination (i) | 88.048±0.002° |
Periastron epoch (T) | 2443563.466±0.005 HJD |
Argument of periastron (ω) (secondary) | 109.83±0.10° |
Semi-amplitude (K1) (primary) | 97.4±0.1 km/s |
Semi-amplitude (K2) (secondary) | 91.2±0.1 km/s |
Details [4] | |
Primary | |
Mass | 6.95 M☉ |
Radius | 3.29 R☉ |
Luminosity | 2,188 L☉ |
Surface gravity (log g) | 4.25 cgs |
Temperature | 21,500 K |
Rotation | 1.45 days |
Rotational velocity (v sin i) | 115 km/s |
Secondary | |
Mass | 7.42 M☉ |
Radius | 3.86 R☉ |
Luminosity | 3,311 L☉ |
Surface gravity (log g) | 4.14 cgs |
Temperature | 22,000 K |
Rotation | 1.40 days |
Rotational velocity (v sin i) | 140 km/s |
Other designations | |
Database references | |
SIMBAD | data |
1 Persei (1 Per) is an eclipsing binary [3] star in the constellation Perseus. Its uneclipsed apparent magnitude is 5.49. The binary star consists of two B2 type main-sequence stars in a 25.9 day eccentric orbit. [5] The stars are surrounded by a faint cloud of gas visible in mid-infrared, although whether they are the origin of the gas or simply passing through it is unclear.
The possible eclipsing binary nature of 1 Persei was first noticed by Donald Kurtz in 1977 when it was used as a comparison star to test for photometric variability of HD 11408. [6] In 1979 French amateur observers succeeded in determining an orbital period of 25.9 days. [7] During the primary eclipse, the brightness drops to magnitude 5.85. In the secondary eclipses, the brightness drops to magnitude 5.74. The eclipses each last for approximately 25 hours. [2]