Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Perseus |
Right ascension | 03h 55m 23.0779s [1] |
Declination | +31° 02′ 45.046″ [1] |
Apparent magnitude (V) | 6.778 [2] (6.03 - 7.00 [3] ) |
Characteristics | |
Spectral type | O9.5IIIe-B0Ve [4] |
U−B color index | −0.790 [2] |
B−V color index | +0.137 [2] |
Variable type | γ Cas + X-ray pulsar [3] |
Astrometry | |
Radial velocity (Rv) | −50.00 [5] km/s |
Proper motion (μ) | RA: −1.397 [1] mas/yr Dec.: −2/254 [1] mas/yr |
Parallax (π) | 1.2342 ± 0.0562 mas [1] |
Distance | 2,600 ± 100 ly (810 ± 40 pc) |
Absolute magnitude (MV) | −3.47 [2] |
Orbit [6] | |
Period (P) | 250.3 days |
Semi-major axis (a) | 2.2 AU |
Eccentricity (e) | 0.111 |
Inclination (i) | 23 - 30° |
Details | |
Mass | 15.5 [7] M☉ |
Radius | 6.5 [7] R☉ |
Luminosity | 29,000 [2] L☉ |
Surface gravity (log g) | 4.0 [2] cgs |
Temperature | 29,500 [7] K |
Rotational velocity (v sin i) | 215 [2] km/s |
Age | 5 [2] Myr |
Other designations | |
Database references | |
SIMBAD | data |
X Persei is a high-mass X-ray binary system located in the constellation Perseus, approximately 950 parsecs away. It is catalogued as 4U 0352+309 in the final Uhuru catalog of X-ray objects.
The conventional star component of X Persei has been classified either as an O-type giant or a B-type main sequence star. It is a Be star, rotating rapidly, and at times surrounded by a disk of expelled material. This qualifies it as a Gamma Cassiopeiae variable, and the visual range is magnitude 6 - 7. In 1989 and 1990, the spectrum of X Persei changed from a Be star to a normal B class star while it faded significantly. This appears to have been caused by the loss of the excretion disk. The disk has since reformed and shows strong emission lines. [9]
The system also contains a neutron star which is a pulsar with an unusually long period of 837 seconds. [6] The pulsar has shown period changes that are associated with mass transfer from the more massive primary star. Between 1973 and 1979 it was seen to increase its rate of spin, associated with a strong x-ray flare and presumed strong mass transfer. Since then the spin has been slowing despite small x-ray flares. [9]
The combination of a neutron star and OB emission line star places X Persei in the Be/X-ray binary class of stars. [9]
There is a faint optical companion separated by 22.5" which the Catalog of Components of Double and Multiple Stars refers to as X Persei B. [10] It is a background red giant [11] and a candidate long period variable with the variable star designation V397 Persei. [3]
9 Aurigae is a star system in Auriga (constellation). It has an apparent magnitude of about 5, making it visible to the naked eye in many suburban skies. Parallax estimates made by the Hipparcos spacecraft put it at about 85.7 light-years from the solar system.
AE Aurigae is a runaway star in the constellation Auriga; it lights the Flaming Star Nebula.
Kappa Boötis is a double star in the constellation Boötes. It has the traditional name Asellus Tertius and the Flamsteed designation 17 Boötis. The components are separated by an angular distance of 13.5 arcsec, viewable in a small telescope. Kappa Boötis is approximately 155 light years from Earth.
15 Cancri is an α2 CVn-type variable star in the zodiac constellation of Cancer, located around 980 light years away. It has the variable star designation BM Cancri ; 15 Cancri is the Flamsteed designation. This system is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of about 5.6. It is moving away from the Earth with a heliocentric radial velocity of 25 km/s.
LS I +61 303 is a microquasar, a binary system containing a massive star and a compact object. The compact object is a pulsar and the system is around 7,000 light-years away.
Vela X-1 is a pulsing, eclipsing high-mass X-ray binary (HMXB) system, associated with the Uhuru source 4U 0900-40 and the supergiant star HD 77581. The X-ray emission of the neutron star is caused by the capture and accretion of matter from the stellar wind of the supergiant companion. Vela X-1 is the prototypical detached HMXB.
V Aquilae is a carbon star and semiregular variable star in the constellation Aquila. It has an apparent magnitude which varies between 6.6 and 8.4 and is located around 400 parsecs (1,300 ly) away.
FK Comae Berenices is a variable star that varies in apparent magnitude between 8.14 and 8.33 over a period of 2.4 days. It is the prototype for the FK Comae Berenices class of variable stars. The variability of FK Com stars may be caused by large, cool spots on the rotating surfaces of the stars. This star is thought to be the result of a recent binary merger, resulting in a high rate of both spin and magnetic activity.
4U 1700-37 is one of the stronger binary X-ray sources in the sky, and is classified as a high-mass X-ray binary. It was discovered by the Uhuru satellite. The "4U" designation refers to the fourth Uhuru catalog.
22 Orionis is a binary star in the equatorial constellation of Orion. It has the Bayer designation o Orionis, while 22 Orionis is the Flamsteed designation. This system is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of 4.74. It is located approximately 1,100 light years away from the Sun based on parallax. The system is moving further from the Earth with a heliocentric radial velocity of +28.80
HD 21278 is a binary star system in the constellation Perseus, located within the 60±7 million year old Alpha Persei Cluster. It has a blue-white hue and is visible to the naked eye with a combined apparent visual magnitude of 4.99. The system is located at a distance of approximately 580 light years from the Sun based on parallax, and it is drifting further away with a radial velocity of +1.20 km/s.
Y Centauri or Y Cen is a semiregular variable star in the constellation of Centaurus.
WR 134 is a variable Wolf-Rayet star located around 6,000 light years away from Earth in the constellation of Cygnus, surrounded by a faint bubble nebula blown by the intense radiation and fast wind from the star. It is five times the radius of the sun, but due to a temperature over 63,000 K it is 400,000 times as luminous as the Sun.
9 Persei is a single variable star in the northern constellation Perseus, located around 4,300 light years away from the Sun. It has the Bayer designation i Persei; 9 Persei is the Flamsteed designation. This body is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of about 5.2. It is moving closer to the Sun with a heliocentric radial velocity of −15.2 km/s. The star is a member of the Perseus OB1 association of co-moving stars.
42 Persei is a binary star system in the northern constellation of Perseus. It has the Bayer designation n Persei, while 42 Persei is the Flamsteed designation. The system is visible to the naked eye as a dim, white-hued point of light with an apparent visual magnitude of 5.11. It is located around 93 parsecs (302 ly) distant from the Sun, but is drifting closer with a radial velocity of −12.4 km/s.
21 Persei is a single, variable star in the northern constellation of Perseus, located about 331 light years away from the Sun. It is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of 5.10 km/s. The object is moving further from the Earth with a heliocentric radial velocity of +8.5 km/s. It has the variable star designation LT Persei; 21 Persei is the Flamsteed designation.
V520 Persei is a blue supergiant member of NGC 869, one of the Perseus Double Cluster open clusters. It is an irregular variable star.
XX Persei is a semiregular variable red supergiant star in the constellation Perseus, between the Double Cluster and the border with Andromeda.
BP Crucis is an X-ray binary system containing a blue hypergiant and a pulsar.
V392 Persei, also known as Nova Persei 2018, is a bright nova in the constellation Perseus discovered on April 29, 2018. It was previously known as a dwarf nova.