75 Cygni

75 Cygni
Observation data
Epoch J2000      Equinox J2000
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 mas[1]
Distance434 ± 10 ly
(133 ± 3 pc)
Absolute magnitude (MV)−0.36[2]
Details
Radius44.61+3.12
−7.77[1] R☉
Luminosity438.5±11.5[1] L☉
Temperature3,954+397
−131[1] K
Other designations
75 Cyg, NSV 13834, BD+42°4177, GC 30338, HD 206330, HIP 106999, HR 8284, SAO 51167, WDS J21402+4316[5]
Database references
SIMBADdata

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]

  1. ^ a b c d e f g h i j k l m Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference perkins1989 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Simbad was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Simbad2 was invoked but never defined (see the help page).