17 Cygni

17 Cygni
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus
Right ascension 19h 46m 25.600s[1]
Declination +33° 43′ 39.35″[1]
Apparent magnitude (V) 5.00[2] + 8.56[3]
Characteristics
Spectral type F7 V[2] + K6 V + K3 V + K3 V[3] + M0.4[4]
B−V color index 0.46[2]
Astrometry
Radial velocity (Rv)+4.1[5] km/s
Proper motion (μ) RA: +22.745 mas/yr[1]
Dec.: –448.311 mas/yr[1]
Parallax (π)47.6516 ± 0.0675 mas[1]
Distance68.45 ± 0.10 ly
(20.99 ± 0.03 pc)
Absolute magnitude (MV)3.40[2]
Details
17 Cyg A
Mass1.24[6] M☉
Radius1.538[7] R☉
Luminosity3.66[8] L☉
Surface gravity (log g)4.262[8] cgs
Temperature6,455[8] K
Metallicity [Fe/H]0.027[8] dex
Rotational velocity (v sin i)9[2] km/s
Age2.8[9] Gyr
17 Cyg B
Mass0.65 M☉
Other designations
17 Cyg, BD+33°3587, GJ 9670, HD 187013, HIP 97295, HR 7534, SAO 68827[10]
Database references
SIMBADdata

17 Cygni is the Flamsteed designation for a multiple star system[3] in the northern constellation of Cygnus. It has an apparent visual magnitude of 5.00,[2] so, according to the Bortle scale, it is visible from suburban skies at night. Measurements of the annual parallax find a shift of 0.0477″,[1] which is equivalent to a distance of around 68.5 ly (21.0 pc) from the Sun. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.451″/year.[11]

This system consists of two visual binary systems that were discovered by John Herschel in the 1820s. Components A and B form a bright, wide pair with an angular separation of 26.0 arcsecond and an estimated orbital period of ~6,200 years. The faint, close system consists of components F and G with a separation of 2.6 arcsecond and a period of 238 years. The two binaries form a hierarchical system with a separation of about 800 arcseconds and orbital period of 3.7 million years or more.[3] At an angular separation of 791.40 arcseconds is a proper motion companion with a classification of M0.4, indicating this is a red dwarf star. At the estimated distance of the pair, this is equal to a projected separation of 16,320 AU.[4] Although the CCDM lists four other companions, these are not associated with the system.[12]

The stellar classification of the primary star, component A, is F7 V,[2] which means it is a main sequence star like the Sun. The star has 1.24[6] times the mass of the Sun and 1.54[7] times the Sun's radius. It is some 2.8[9] billion years old and shines with 3.66[8] times the Sun's luminosity. The effective temperature of the stellar atmosphere is 6,455[8] K, giving it the yellow-white hued glow of an F-type star.[13]

  1. ^ a b c d e Cite error: The named reference GaiaEDR3 was invoked but never defined (see the help page).
  2. ^ a b c d e f g Cite error: The named reference Takeda2005 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Romanenko2017 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Dhital2010 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Nordström2004 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Halbwachs2018 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Schofield_et_al_2019 was invoked but never defined (see the help page).
  8. ^ a b c d e f Cite error: The named reference Takeda2007 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Holmberg2009 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Lepine2005 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Phillips2010 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference csiro was invoked but never defined (see the help page).