Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Vulpecula |
Right ascension | 20h 15m 30.2386s [2] |
Declination | +23° 30′ 32.051″ [2] |
Apparent magnitude (V) | 5.15 [3] |
Characteristics | |
Spectral type | G9Ib-II + B8V [4] |
U−B color index | +1.03 [5] |
B−V color index | +0.68 [5] |
Variable type | Algol [3] |
Astrometry | |
Radial velocity (Rv) | −22.8±0.9 [6] km/s |
Proper motion (μ) | RA: 2.852±0.067 [2] mas/yr Dec.: −7.278±0.071 [2] mas/yr |
Parallax (π) | 2.1872 ± 0.0850 mas [2] |
Distance | 1,490 ± 60 ly (460 ± 20 pc) |
Absolute magnitude (MV) | −3.67 [7] (−3.5 / −0.1) [8] |
Orbit [4] | |
Period (P) | 249.18±0.010 d |
Eccentricity (e) | 0.011 |
Inclination (i) | 81.34±0.02 [1] ° |
Argument of periastron (ω) (secondary) | 0 (assumed)° |
Semi-amplitude (K1) (primary) | 27.10±0.21 km/s |
Semi-amplitude (K2) (secondary) | 40.0±1.0 km/s |
Details | |
22 Vul A | |
Mass | 4.649 [4] M☉ |
Radius | 96 [4] R☉ |
Luminosity | 2,188 [1] L☉ |
Temperature | 4,699 [4] K |
Rotation | 142 - 165 days [1] |
Rotational velocity (v sin i) | 16 - 20 [1] km/s |
22 Vul B | |
Mass | 3.150 [4] M☉ |
Radius | 3.4 [4] R☉ |
Luminosity | 123 [1] L☉ |
Temperature | 11,995 [4] K |
Age | 135.1 [4] Myr |
Other designations | |
Database references | |
SIMBAD | data |
22 Vulpeculae is a binary star system in the northern constellation Vulpecula. Based on its parallax, it is located some 1,490 light-years away, [2] and it has an apparent magnitude of about 5.2, making it visible to the naked eye. The system is moving closer to the Earth with a heliocentric radial velocity of −23 km/s.
The pair have an orbital period of 249 d in an almost-circular orbit. The primary component is a G-type bright giant. It is over four times as massive as the Sun, and over 96 times as wide. Its companion is a B-type main-sequence star, 3.4 times as massive as the Sun. [8] Although the secondary has an effective temperature of nearly 12,000 K and the primary just 4,700 K, the large size of the cooler star means it is nearly 20 times as luminous at 2,200 L☉. The primary star is rotating slowly with a rotation period that appears to be between about 140 and 165 days, unexpectedly faster than the orbital period. Different parts of its atmosphere may be rotating at different speeds. [1] The hot secondary is rotating much faster, possibly at 350 km/s. [10]
The two stars have an orbit that is oriented in such a way that they periodically eclipse each other, each star alternately blocking the light of the other. For that, it has been given the variable star designation QS Vulpeculae; [9] 22 Vulpeculae is the Flamsteed designation. The maximum drop in visual apparent magnitude is 0.05 magnitudes when the hot secondary is completely hidden by the large cool primary. The eclipses are deeper at shorter wavelengths because a greater proportion of the short-wavelength radiation comes from the hot star. The primary eclipses last for eight days at visual wavelengths, but partial phases can be detected for up to 17 days at ultraviolet wavelengths due to the expanded atmosphere and wind of the primary star. Secondary eclipse, where the hot star transits the cooler one, are undetectable, and ellipsoidal variations due to distortion of the large primary produce brightness changes of less than 1.5%. [1]
Alpha Vulpeculae, officially named Anser, is the brightest star in the constellation of Vulpecula. It is approximately 291 light-years from Earth. It forms a wide optical binary with 8 Vulpeculae.
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 86 light-years from the solar system, although individual Gaia Data Release 3 parallaxes place all three components at 88 light years.
RT Aurigae is a yellow supergiant variable star in the constellation Auriga, about 1,500 light years from Earth.
AR Aurigae, also known by its Flamsteed designation 17 Aurigae, is a binary star in the constellation Auriga. Based on parallax measurements made by the Hipparcos spacecraft, it is approximately 461 light-years from Earth.
VV Cephei, also known as HD 208816, is an eclipsing binary star system located in the constellation Cepheus, approximately 5,000 light years from Earth. It is both a B[e] star and shell star.
13 Vulpeculae is a blue giant with a stellar classification of class B9.5III in the northern constellation Vulpecula. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of 4.57 and it is approximately 339 light years away from the Sun based on parallax. The star is radiating 180 times the luminosity of the Sun from its photosphere at an effective temperature of 8,801 K.
15 Vulpeculae is a variable star in the northern constellation of Vulpecula, located approximately 243 light years away based on parallax. It has the variable star designation NT Vulpeculae; 15 Vulpeculae is the Flamsteed designation. It is visible to the naked eye as a faint, white-hued star with a typical apparent visual magnitude of 4.66. This object is moving closer to the Earth with a heliocentric radial velocity of −26 km/s.
1 Vulpeculae is a class B4IV star in the constellation Vulpecula. Its apparent magnitude is 4.77 and it is approximately 780 light years away based on parallax.
12 Vulpeculae is a star in the northern constellation of Vulpecula, located approximately 630 light years away based on parallax. It has the variable star designation V395 Vul; 12 Vulpeculae is the Flamsteed designation. This object is visible to the naked eye as a faint, blue-white hued star with a baseline apparent visual magnitude of 4.928. It is moving closer to the Earth with a heliocentric radial velocity of -25 km/s.
HR 2554, also known as V415 Carinae and A Carinae, is an eclipsing spectroscopic binary of the Algol type in the constellation of Carina whose apparent visual magnitude varies by 0.06 magnitude and is approximately 4.39 at maximum brightness. Its primary is a G-type bright giant star and its secondary is an A-type main-sequence star. It is approximately 553 light-years from Earth.
LY Aurigae is a multiple star system in the constellation Auriga. It is an eclipsing binary variable star, dropping in brightness by 0.7 magnitudes every 4 days. The system is around a thousand light years away in the Auriga OB1 stellar association.
Delta Sagittae is a binary star in the constellation of Sagitta, with an apparent magnitude of +3.68. The primary component is a red M-type bright giant, and the secondary is a B-type main-sequence star. It is approximately 430 light years from Earth, based on its Gaia Data Release 2 parallax.
1 Persei is an eclipsing binary 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. 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.
31 Cygni, also known as ο1 Cygni, Omicron1 Cygni, or V695 Cygni, is a triple star system about 750 light years away in the constellation Cygnus.
Psi2 Orionis a binary star system in the equatorial constellation of Orion. It has an apparent visual magnitude of 4.6, indicating that it is visible to the naked eye. Based upon an annual parallax shift of 2.87 mass, it is roughly 1,100 light years distant from the Sun.
WR 12 is a spectroscopic binary in the constellation Vela. It is an eclipsing binary consisting of a Wolf-Rayet star and a luminous companion of unknown spectral type. The primary is one of the most luminous stars known.
WR 9 is a spectroscopic binary in the constellation Puppis consisting of a Wolf-Rayet star and a class O star. It is around 12,000 light years away.
Gliese 569 is a ternary star system composed of a main-sequence star orbited by a pair of brown dwarfs in the constellation of Boötes about 32 light years away.
ER Vulpeculae is a binary star system in the northern constellation of Vulpecula, abbreviated ER Vul. It is a variable star system with a brightness that ranges from an apparent visual magnitude of 7.27 down to 7.49, which is too faint to be visible to the naked eye. This system is located at a distance of 165 light years from the Sun based on parallax measurements. It is drifting closer with a radial velocity of −25 km/s.
PU Vulpeculae is a very slowly evolving symbiotic nova in the northern constellation of Vulpecula, abbreviated PU Vul. It is too faint to be visible to the naked eye, reaching a maximum apparent visual magnitude of 8.7 following a minimum of 16.6. The system is located at a distance of approximately 17,000 light years from the Sun based on parallax measurements.