7 Draconis

7 Draconis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Draco
Right ascension 12h 47m 34.34473s[1]
Declination +66° 47′ 25.0977″[1]
Apparent magnitude (V) 5.43[2]
Characteristics
Spectral type K5 III[2]
B−V color index 1.567±0.006[2]
Astrometry
Radial velocity (Rv)+11.33[3] km/s
Proper motion (μ) RA: 6.674[1] mas/yr
Dec.: −6.498[1] mas/yr
Parallax (π)4.1601 ± 0.1056 mas[1]
Distance780 ± 20 ly
(240 ± 6 pc)
Absolute magnitude (MV)−1.35[2]
Details
Radius67[4] R☉
Luminosity1,024.45[2] L☉
Temperature3,945[5] K
Other designations
Tianyi, 7 Dra, BD+67°764, FK5 3020, HD 111335, HIP 62423, HR 4863, SAO 15902[3]
Database references
SIMBADdata

7 Draconis, also named Tianyi /tiænˈjiː/,[6] is a single[7] star in the northern circumpolar constellation of Draco. It is visible to the naked eye as a faint orange-hued star with a stellar classification of 5.43.[2] Based upon an annual parallax shift of 4.16 mas as seen from the Earth,[1] the star is located approximately 780 light-years from the Sun.

This is an evolved giant star with a stellar classification of K5 III.[2] The measured angular diameter of this star, after correction for limb darkening, is 2.61±0.03 mas.[8] At its estimated distance, this yields a physical size of about 67 times the radius of the Sun.[4] It is radiating about 1,024[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,945 K.[5]

  1. ^ a b c d e f Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d e f g h Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference lang2006 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference McDonald2012 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference IAU-LSN was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Richichi2005 was invoked but never defined (see the help page).