8 Draconis

8 Draconis

A light curve for IR Draconis, adapted from Aerts et al. (1998)[1]
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Draco
Right ascension 12h 55m 28.550015s[2]
Declination +65° 26′ 18.5079″[2]
Apparent magnitude (V) 5.225[3]
Characteristics
Spectral type F1VmA7(n)[4]
B−V color index 0.303±0.005[5]
Variable type Gamma Doradus[6]
Astrometry
Radial velocity (Rv)+9.0[7] km/s
Proper motion (μ) RA: −4.235[2] mas/yr
Dec.: −30.174[2] mas/yr
Parallax (π)34.0276 ± 0.0922 mas[2]
Distance95.9 ± 0.3 ly
(29.39 ± 0.08 pc)
Absolute magnitude (MV)2.90[5]
Details
Mass1.56[8] M☉
Radius1.50[8] R☉
Luminosity5.75[5] L☉
Surface gravity (log g)4.01[4] cgs
Temperature7,129[4] K
Metallicity [Fe/H]−0.14[4] dex
Rotational velocity (v sin i)119.6[9] km/s
Age250±200[8] Myr
Other designations
Taiyi, 8 Dra, IR Draconis, BD+66°778, FK5 486, HD 112429, HIP 63076, HR 4916, SAO 15941[10]
Database references
SIMBADdata

8 Draconis, formally named Taiyi /ˌtaɪˈjiː/,[11] is a single[12] star in the northern circumpolar constellation of Draco. Based upon an annual parallax shift of 34.14 mas as seen from the Earth,[13] the star is located approximately 96 light-years from the Sun. It is moving further away with a heliocentric radial velocity of +9 km/s,[7] having come within 40.6 ly some 2.6 million years ago.[5]

This is an F-type main-sequence star with a stellar classification of F1VmA7(n).[4] It is a Gamma Doradus variable star with a brightness variation of about one tenth of a magnitude.[6] 8 Dra has a relatively high rate of rotation, showing a projected rotational velocity of 120 km/s.[9] The star has 1.56 times the mass of the Sun and 1.50 times the Sun's radius.[8] It is radiating 5.75[5] times the Sun's luminosity from its photosphere at an effective temperature of 7,129 K.[4] An infrared excess has been detected at wavelengths of 24 and 70μm, which suggests the presence of a circumstellar disk orbiting the star.[8]

  1. ^ Cite error: The named reference Aerts was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference tycho2 was invoked but never defined (see the help page).
  4. ^ a b c d e f Cite error: The named reference gray was invoked but never defined (see the help page).
  5. ^ a b c d e Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference gcvs was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference rv was invoked but never defined (see the help page).
  8. ^ a b c d e Cite error: The named reference Plavchan2009 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Schröder2009 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 IAU-LSN was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference hipparcos was invoked but never defined (see the help page).