Algol
The reid dot shaws the location o Algol in Perseus. | |
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Perseus |
Richt ascension | 03h 08m 10.1315s[1] |
Declination | +40° 57′ 20.332″[1] |
Apparent magnitude (V) | 2.12[1] |
Chairactereestics | |
Spectral type | B8V (A)[1] /K0IV (B)[2] /A5V (C) |
U−B colour index | −0.37 |
B−V colour index | −0.05 |
Variable teep | Eclipsin binary |
Astrometry | |
Radial velocity (Rv) | 3.7 km/s |
Proper motion (μ) | RA: 2.39 mas/yr Dec.: −1.44 mas/yr |
Parallax (π) | 35.14 ± 0.90 mas |
Distance | 93 ± 2 ly (28.5 ± 0.7 pc) |
Absolute magnitude (MV) | −0.15 |
Details | |
Mass | 3.59/0.79/1.67 M☉ |
Radius | 4.13[3]/3.0/0.9 R☉ |
Luminosity | 98/3.4/4.1 L☉ |
Temperatur | 9,200[3]/4,500/8,500 K |
Metallicity | Nae available |
Rotation | 65 km/s |
Age | < ×108 years 3 |
Ither designations | |
Algol (Beta Per, β Persei, β Per), kent colloquially as the Demon Starn, is a bricht starn in the constellation Perseus. It is ane o the best kent eclipsin binaries, the first such starn tae be discovered, an an aa ane o the first (non-nova) variable starns tae be discovered. Algol is actually a three-starn seestem (Beta Persei A, B, an C) in which the lairge an bricht primary Beta Persei A is regularly eclipsed bi the dimmer Beta Persei B. Thus, Algol's magnitude is usually near-constant at 2.1, but regularly dips tae 3.4 every twa days, 20 oors an 49 minutes durin the roughly 10-oor lang partial eclipses. Thare is an aa a seicontary eclipse (the "seicont minimum") when the brichter starn occults the fainter seicontary. This seicontary eclipse can anly be detectit photoelectrically.[4] Algol gies its name tae its class o eclipsin variable, kent as Algol variables.
References[eedit | eedit soorce]
- ↑ a b c d Database entry for Algol A, SIMBAD. Accessed online February 9, 2008.
- ↑ Database entry for Algol B, SIMBAD. Accessed online February 9, 2008.
- ↑ a b Rhee, Joseph H.; et al. (2007), "Characterization of Dusty Debris Disks: The IRAS and Hipparcos Catalogs", The Astrophysical Journal, 660 (2): 1556–1571, arXiv:astro-ph/0609555, Bibcode:2007ApJ...660.1556R, doi:10.1086/509912 Unknown parameter
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ignored (help) - ↑ Beta Persei, American Association of Variable Star Observers. https://web.archive.org/web/20030705115540/http://www.aavso.org/vstar/vsots/0199.shtml