Observation data Equinox J2000.0]] (ICRS) | |
---|---|
Constellation | Cygnus |
Right ascension | 21h 40m 11.10795s[1] |
Declination | +43° 16′ 25.8161″[1] |
Apparent magnitude (V) | 5.09[2] |
Characteristics | |
Evolutionary stage | red giant |
Spectral type | M1IIIab[3] |
B−V color index | 1.601±0.006[2] |
Variable type | suspected[4] |
Astrometry | |
Radial velocity (Rv) | −29.25±0.14[1] km/s |
Proper motion (μ) | RA: +62.366[1] mas/yr Dec.: +15.488[1] mas/yr |
Parallax (π) | 7.5210 ± 0.1706[1] mas |
Distance | 434 ± 10 ly (133 ± 3 pc) |
Absolute magnitude (MV) | −0.36[2] |
Details | |
Radius | 44.61+3.12 −7.77[1] R☉ |
Luminosity | 438.5±11.5[1] L☉ |
Temperature | 3,954+397 −131[1] K |
Other designations | |
Database references | |
SIMBAD | data |
75 Cygni is a binary star[6] system in the northern constellation of Cygnus. It is visible to the naked eye as a dim, reddish-hued point of light with an apparent visual magnitude of 5.09.[2] The system is located at a distance of about 434 light years from the Sun, based on parallax, and is drifting closer with a radial velocity of −29 km/s.[1]
The pair had an angular separation of 2.7″ as of 2008, with the companion having a visual magnitude of 10.7.[6] The brighter magnitude 5.18[6] primary is an aging red giant star with a stellar classification of M1IIIab.[3] Having exhausted the supply of hydrogen at its core, it has expanded to around 45[1] times the radius of the Sun. It is a suspected variable star of unknown type and amplitude.[4] The star is radiating 439[1] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,954 K.[1]
An optical companion, with a spectral type of K, is about an arcminute away and has an apparent magnitude of 10.14.[7]
Original source: https://en.wikipedia.org/wiki/75 Cygni.
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