Coordinates: 23h 30m 0s, +58° 33′ 0″
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Cassiopeia [2] |
AB | |
Right ascension | 23h 30m 01.93946s [3] |
Declination | +58° 32′ 56.1120″ [3] |
Apparent magnitude (V) | 4.883 (4.912 / 8.814) [4] |
CD | |
Right ascension | 23h 29m 52.2802s [5] |
Declination | +58° 32′ 54.458″ [5] |
Apparent magnitude (V) | 7.09 [6] |
Characteristics | |
AB | |
Spectral type | B4 V + A6 V [4] |
U−B color index | −0.62 [7] |
B−V color index | −0.12 [7] |
Variable type | Algol [8] |
CD | |
Spectral type | B9 V [6] |
U−B color index | −0.14 [7] |
B−V color index | +0.01 [7] |
FG | |
Spectral type | F7 IV + F9 V [9] |
Astrometry | |
Radial velocity (Rv) | −15.9±0.9 [10] km/s |
Proper motion (μ) | RA: 17.90 [3] mas/yr Dec.: 4.15 [3] mas/yr |
Parallax (π) | 5.25 ± 0.52 mas [3] |
Distance | 620 ± 60 ly (190 ± 20 pc) |
Aa | |
Absolute magnitude (MV) | −1.87±0.13 [4] |
Absolute bolometric magnitude (Mbol) | −3.56±0.13 [4] |
Ab | |
Absolute magnitude (MV) | 2.20±0.11 [4] |
Absolute bolometric magnitude (Mbol) | 2.18±0.11 [4] |
Orbit [4] | |
Primary | Aa |
Companion | Ab |
Period (P) | 6.0663170 d |
Eccentricity (e) | 0.240 |
Inclination (i) | 85.34±0.50° |
Periastron epoch (T) | JD 2436847.9404±0.0055 |
Argument of periastron (ω) (secondary) | 41.82±0.47° |
Details [4] | |
Aa | |
Mass | 5.90±0.20 M☉ |
Radius | 5.05±0.06 R☉ |
Surface gravity (log g) | 3.80±0.02 cgs |
Temperature | 17,200±500 K |
Ab | |
Mass | 1.86±0.06 M☉ |
Radius | 1.60±0.03 R☉ |
Surface gravity (log g) | 4.30±0.02 cgs |
Temperature | 8,150±200 K |
Other designations | |
AR Cassiopeiae (AB): 1H. Cas [11] , AR Cas, BD+57°2748, HD 221253, HIP 115990, HR 8926, SAO 35478 [8] | |
HD 221237 (CD): BD+57°2747, HD 221237, SAO 35476 | |
FG: UCAC4 743-089692 | |
Database references | |
SIMBAD | AR Cas (AB) |
CD | |
D | |
F | |
G |
AR Cassiopeiae (AR Cas) is a variable star in the constellation of Cassiopeia. It is thought to be a member of a septuple star system, one of only two known star systems with a multiplicity of 7, the other being Nu Scorpii. [12] [9]
The multiple star system as a whole has the designations ADS 16795, CCDM J23300+5833, and WDS J23300+5833AB in the Aitken Double Star Catalogue, the Catalogue of Components of Double and Multiple Stars, and the Washington Double Star Catalog respectively. [8]
AR Cassiopeiae has been referred to as IH Cas in some literature, looking similar to a variable star designation although not a valid one since the second letter of a variable star designation is always equal to the first or occurs later in the alphabet. The origin of the designation "IH Cassiopeiae" is from the 17th century catalogue and constellation map by Johannes Hevelius, which was kept in use due to the lack of a Flamsteed designation or Bayer designation for the star. [11] It was the first star in Cassiopeia that Flamsteed's edition of Hevelius catalogued, [13] thus "1 Hev. Cas" or "1 H. Cas" (similar to Gould designations), which becomes IH Cas through corruption. [11]
The primary star system, AR Cassiopeiae, is a triple. AR Cassiopeiae B is located 0.800″ away from AR Cassiopeiae A. [9] AR Cassiopeiae A itself is an Algol-type eclipsing binary with an orbital period of about 6.07 days. [4] Its primary is a B-type main-sequence star, and the secondary an A-type main-sequence star. The secondary star may be an Am star. [4]
Farther out are two other stars, designated components C and D. They are 76.1″, or about 1.27′, away from the central system. [9] Their combined spectrum matches that of another B-type main-sequence star. [6] This pair is also designated HD 221237. [6] 67.2″ (1.12′) away from AR Cassiopeiae is another pair of stars, F and G, both F-type stars. [9]
All these stars are known to be common proper motion companions. [9] However, the star listed as component E in most multiple star catalogues is an unrelated background star.
Alpha Cassiopeiae or α Cassiopeiae, also named Schedar, is a second magnitude star in the northern constellation of Cassiopeia. Though listed as the "alpha star" by Johann Bayer, α Cas's visual brightness closely matches the 'beta' (β) star in the constellation and it may appear marginally brighter or dimmer, depending on which passband is used. However, recent calculations from NASA's WISE telescope confirm that α Cas is the brightest in Cassiopeia, with an apparent magnitude of 2.240. Its absolute magnitude is 18 times greater than β Cas, and it is located over four times farther away from the Sun.
Xi Scorpii is a quintuple star system in the constellation Scorpius. It was assigned this designation by Bayer, although Ptolemy had catalogued the star in Libra. Flamsteed assigned it the designation 51 Librae, but this has fallen out of use since modern constellation boundaries assign the star to Scorpius.
14 Aurigae is a quadruple star system located 269 light years away from the Sun in the zodiac constellation of Auriga. It has the variable star designation KW Aurigae, whereas 14 Aurigae is the Flamsteed designation. It is visible to the naked eye as a faint, white-hued star with a combined apparent visual magnitude of 5.01. The system is moving closer to the Sun with a heliocentric radial velocity of −9 km/s.
Theta Cassiopeiae or θ Cassiopeiae is a solitary star in the northern constellation of Cassiopeia. It shares the traditional name Marfak with μ Cassiopeiae, positioned less than half a degree to the WSW, which is derived from the Arabic term Al Marfik or Al Mirfaq (المرفق), meaning "the elbow". At an apparent visual magnitude of 4.3, Theta Cassiopeiae is visible to the naked eye. Based upon an annual parallax shift of 24.42 mas, it is located about 134 light years from the Sun. It has a total annual proper motion of 0.227 arcseconds per year, and is slowly drifting further away from the Sun with a radial velocity of 2.5 km/s.
Zeta Cassiopeiae, Latinized from ζ Cassiopeiae, and officially named Fulu, is a variable star in the constellation of Cassiopeia. It has a blue-white hue and is classified as a B-type subgiant with an apparent magnitude of +3.66. Based upon parallax measurements, it is approximately 590 light-years from the Sun.
Iota Cassiopeiae is a star system in the constellation Cassiopeia. The system has a combined apparent magnitude of 4.53, making it visible to the naked eye. Based on its parallax, it is located about 133 light-years from Earth.
48 Cassiopeiae is a triple star system in the northern constellation of Cassiopeia. It is visible to the naked eye with a combined apparent visual magnitude of 4.49. With an annual parallax shift of 28.36±0.44 mas as seen from Earth's orbit, it is located approximately 115 light years away. The system is moving closer with a heliocentric radial velocity of −12.4 km/s.
Upsilon1 Cassiopeiae is an astrometric binary star system in the northern constellation of Cassiopeia. It is visible to the naked eye with an apparent visual magnitude of 4.82. Based upon an annual parallax shift of 9.93 mas as seen from Earth, this system is located about 330 light years from the Sun.
Lambda Cassiopeiae, Latinized from λ Cassiopeiae, is a binary star system, in the northern constellation of Cassiopeia. The system has a combined apparent magnitude of +4.74, making it faintly visible to the naked eye. With an annual parallax shift of 8.64 mass, it is approximately 380 light years from Earth. The system is moving closer to the Sun with a radial velocity of −12 km/s.
Tau Cassiopeiae is a solitary, orange hued star in the northern constellation of Cassiopeia. It is bright enough to be seen with the naked eye, having an apparent visual magnitude of +4.86. Based upon an annual parallax shift of 18.75 mas as seen from Earth, this system is located about 174 light years from the Sun.
2 Centauri is a single star in the southern constellation of Centaurus, located approximately 183 light-years from Earth. It has the Bayer designation g Centauri; 2 Centauri is the Flamsteed designation. This object is visible to the naked eye as faint, red-hued star with an apparent visual magnitude of 4.19. It is moving away from the Earth with a heliocentric radial velocity of +41 km/s. The star is a member of the HD 1614 supercluster.
Upsilon Ceti, Latinized from υ Ceti, is a solitary star in the equatorial constellation of Cetus. It is visible to the naked eye with an apparent visual magnitude of 3.95. Based upon an annual parallax shift of 11.14 mas, it is located about 293 light years from the Sun.
Pi2 Cygni, Latinized from π2 Cygni, is a triple star system in the northern constellation of Cygnus. It is visible to the naked eye about 2.5° east-northeast of the open cluster M39, having an apparent visual magnitude of 4.24. Based upon an annual parallax shift of 2.95 mas, it is located at a distance of roughly 1,100 light years from the Sun.
YZ Cassiopeiae is a star system 103.8 parsecs (339 ly) away from Earth, in the constellation Cassiopeia. It comprises three stars: an eclipsing Algol-type binary and a visually fainter star about 3000 AU distant.
45 Herculis is a solitary variable star in the northern constellation Hercules. It has the Bayer designation l Herculis and the variable star designation V776 Herculis. The Flamsteed designation for this star comes from the publication Historia Coelestis Britannica by John Flamsteed. It is the 45th star in Flamsteed list of stars in the constellation Hercules, and is visible to the naked eye with a baseline apparent visual magnitude of 5.22. Parallax measurements show this star to be about 400 light-years away from the Solar System. It is moving closer to the Earth with a heliocentric radial velocity of −16 km/s.
56 Ceti is a single star located in the equatorial constellation of Cetus. Not found in the original Bayer catalogue, it was given the Bayer-like designation Upsilon1 Ceti by Flamsteed to distinguish it from Bayer's Upsilon Ceti, which Flamsteed designated Upsilon2 or 59 Ceti. In 1801, J. E. Bode included this designation in his Uranographia, but the superscripted designations Upsilon1 and Upsilon2 are not in general use today. 56 Ceti is the Flamsteed designation for this star.
39 Draconis is a wide binary star system in the northern circumpolar constellation of Draco. It has the Bayer designation b Draconis, while 39 Draconis is the Flamsteed designation. This system is visible to the naked eye as a dim, white-hued point of light with an apparent visual magnitude of 5.0. Parallax measurements made by the Hipparcos spacecraft put it at a distance of 184 light-years, or 56 parsecs away from the Sun. The system is moving closer to the Earth with a heliocentric radial velocity of -24.5 km/s.
Omicron Hydrae is the Bayer designation for a solitary star in the equatorial constellation Hydra. At one time it bore the Flamsteed designation 25 Crateris, but this is no longer used by astronomers so as to avoid confusion. With an apparent visual magnitude of 4.70, this star is visible to the naked eye. Based upon an annual parallax shift of 7.27 mas, it is located around 449 light years from the Sun.
1 Lyncis is a single star in the northern constellation of Lynx. It is also known by its variable star designation of UW Lyncis; 1 Lyncis is the Flamsteed designation. This object is visible to the naked eye as a faint, reddish-hued star with an apparent visual magnitude of 4.95. It is moving further from the Earth with a heliocentric radial velocity of 12 km/s.
ADS 1359 is a quadruple star system in the constellation Cassiopeia. It is composed of two sun like stars in an eclipsing binary with a 2.5-day period, which is in turn orbited by an A-type main-sequence star with a 185-year orbital period. There is also HD 236848 which is a distant proper motion companion.