Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Cassiopeia |
Right ascension | 23h 09m 44.1389s [1] |
Declination | +59° 19′ 57.687″ [1] |
Apparent magnitude (V) | +5.679 [2] |
Characteristics | |
Spectral type | A4II [3] (kA5hA7mF0) [4] |
U−B color index | +0.31 [5] |
B−V color index | +0.33 [5] |
Astrometry | |
Radial velocity (Rv) | −13.58±0.15 [1] km/s |
Proper motion (μ) | RA: +0.335 [1] mas/yr Dec.: +0.552 [1] mas/yr |
Parallax (π) | 1.1900 ± 0.0386 mas [1] |
Distance | 2,740 ± 90 ly (840 ± 30 pc) |
Absolute magnitude (MV) | −2.92 [6] |
Details | |
Mass | 5.3 [7] M☉ |
Radius | 41 [8] R☉ |
Luminosity | 3,014 [8] L☉ |
Surface gravity (log g) | 1.93 [7] cgs |
Temperature | 8,012 [9] K |
Metallicity [Fe/H] | −0.23 [7] dex |
Rotational velocity (v sin i) | 5.3 [10] km/s |
Other designations | |
Database references | |
SIMBAD | data |
2 Cassiopeiae (2 Cas) is a white bright giant in the constellation Cassiopeia, about 2,800 light years away. It is a chemically peculiar Am star.
2 Cassiopeiae has been described as an A4 type bright giant, buts its spectrum is not easy to classify. The calcium K absorption lines indicate a hotter type than the hydrogen lines, while other metals indicate a cooler type, possibly as cool as F0. This makes it an Am star, a type of magnetic chemically peculiar star with unusual abundances showing in its spectrum due to chemical stratification in its atmosphere caused by slow rotation. [5]
About six times as massive as the Sun and 3,000 times as luminous, it has expanded away from the main sequence after exhausting its core hydrogen and now has an effective temperature of about 8,000 K . Some researchers have suggested that it is post-AGB star. [3]
2 Cassiopeiae has a number of close companions listed in multiple star catalogues, [11] but none are thought to be gravitationally associated. [12]
Lambda1 Tucanae is the Bayer designation for one member of a pair of stars sharing a common proper motion through space, which lie within the southern constellation of Tucana. As of 2013, the pair had an angular separation of 20.0 arc seconds along a position angle of 82°. Together, they are barely visible to the naked eye with a combined apparent visual magnitude of 6.21. Based upon an annual parallax shift for both stars of approximately 16.5 mas as seen from Earth, this system is located roughly 198 light years from the Sun.
8 Andromedae, abbreviated 8 And, is a probable triple star system in the northern constellation of Andromeda. 8 Andromedae is the Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 4.82. Based upon an annual parallax shift of 5.7 mas, it is located about 570 light years from the Earth. It is moving closer with a heliocentric radial velocity of −8 km/s.
Mu Cassiopeiae, Latinized from μ Cassiopeiae, is a binary star system in the constellation Cassiopeia. This system shares the name Marfak with Theta Cassiopeiae, and the name was from Al Marfik or Al Mirfaq (المرفق), meaning "the elbow". It is dimly visible to the naked eye as a point of light with an apparent visual magnitude of 5.16. The system is located at a distance of 24.6 light years from the Sun based on parallax, and is moving closer with a high radial velocity of −98 km/s. This star will move into the constellation Perseus around 5200 AD.
V337 Carinae is a K-type bright giant star in the constellation of Carina. It is an irregular variable and has an apparent visual magnitude which varies between 3.36 and 3.44.
HD 69863 is a binary star system in the southern constellation of Carina. It is visible to the naked eye as a dim point of light with a combined apparent visual magnitude of 5.16. The system is located at a distance of about255 light years from the Sun based on parallax. The dual nature of this system was announced in 1832 by German astronomer Carl Rümker. As of 2015, the pair had an angular separation of 4.10″ along a position angle of 70°.
4 Cassiopeiae is a red giant in the northern constellation of Cassiopeia, located approximately 790 light-years away from the Sun. It is visible to the naked eye as a faint, red-hued star with a baseline apparent visual magnitude of 4.96. At the distance of this system, its visual magnitude is diminished by an extinction of 0.56 due to interstellar dust. This system is moving closer to the Earth with a heliocentric radial velocity of −39 km/s.
Theta Persei is a star system 37 light years away from Earth, in the constellation Perseus. It is one of the closest naked-eye stars.
49 Cassiopeiae is a binary star system in the northern circumpolar constellation of Cassiopeia. It is visible to the naked eye as a faint, yellow-hued point of light with an apparent visual magnitude of 5.22. The system is located about 412 light years away from the Sun, based on parallax. The pair had an angular separation of 5.40″ along a position angle of 244°, as of 2008, with the brighter component being of magnitude 5.32 and its faint companion having magnitude 12.30.
HD 225218 is a quadruple star system in the northern constellation of Andromeda. The primary component, HD 225218 A, is a giant star with a stellar classification of B9III, an apparent magnitude of 6.16, and is a candidate Lambda Boötis star. It has a fainter, magnitude 9.65 companion, HD 225218 B, at an angular separation of 5.2″ along a position angle of 171°. The primary itself has been identified as a binary star system through interferometry, with the two components separated by 0.165″. The pair, HD 225218 Aa and Ab, orbit each other with a period of about 70 years and an eccentricity of 0.515. Component B is likewise a spectroscopic binary.
HD 30442 is a solitary star in the northern circumpolar constellation Camelopardalis. It is faintly visible to the naked eye with an apparent magnitude of 5.47 and is estimated to be 403 light years away from the Solar System. The object has a heliocentric radial velocity of −37 km/s, indicating that it is drifting closer.
1 Serpentis is a red giant in the constellation Virgo with an apparent magnitude of 5.5. It is a red clump giant, a cool horizontal branch star that is fusing helium in its core. It has expanded to over 13 times the radius of the Sun and although it is cooler at 4,581 K it is 77 times more luminous. It is 322 light years away.
1 Camelopardalis is a double star system in the constellation Camelopardalis. Its combined apparent magnitude is 5.56 and it is approximately 800 parsecs (2,600 ly) away.
HD 102350 is a single star in the constellation Centaurus. It has a yellow hue and is visible to the naked eye with an apparent visual magnitude of 4.11. The distance to this star is approximately 390 light years based on parallax, but it is drifting closer with a radial velocity of −3 km/s. It has an absolute magnitude of −1.51.
f Eridani is a binary, or possibly a triple, star system in the equatorial constellation of Eridanus, consisting of stars HD 24071 and HD 24072. They share a single Hipparcos catalogue entry, HIP 17797, but have separate Bright Star Catalogue listings, HR 1189 and 1190. f Eridani is the Bayer designation of the pair.
Tau1 Hydrae is a triple star system in the equatorial constellation of Hydra. Based upon the annual parallax shift of the two visible components as seen from Earth, they are located about 18 parsecs (59 ly) from the Sun. The system has a combined apparent visual magnitude of +4.59, which is bright enough to be visible to the naked eye at night.
HD 79940 is a single star in the southern constellation of Vela. It has the Bayer designation of k Velorum; HD 79940 is the identifier from the Henry Draper Catalogue. This star has a yellow-white hue and is faintly visible to the naked eye as a point light source with an apparent visual magnitude of 4.63. It is located at a distance of approximately 158 light-years from the Sun based on parallax, and is drifting further away with a radial velocity of +6 km/s.
η Microscopii, Latinised as Eta Microscopii, is a solitary star in the constellation Microscopium. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.53. The star is located around 910 light-years distant from the Sun based on parallax, and is drifting further away with a radial velocity of +22 km/s.
BO Carinae, also known as HD 93420, is an irregular variable star in the constellation Carina.
HD 199223 is a double star in the equatorial constellation Delphinus. However, the system was originally in Equuleus prior to the creation of official IAU constellation borders. The components have a separation of 2″ at a position angle of 282° as of 2016. They have apparent magnitudes of 6.34 and 7.49 and distances of 354 and 359 light years respectively. The system is drifting closer with a radial velocity of −33 km/s.
9 Cassiopeiae is a white giant star in the constellation Cassiopeia, about 2,370 light years away.