HD 221525

HD 221525
Diagram showing star positions and boundaries of the Cepheus constellation and its surroundings
Location of HD 221525 (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cepheus
Right ascension 23h 27m 00.91338s[1]
Declination 87° 18′ 27.0304″[1]
Apparent magnitude (V) 5.56[2]
Characteristics
Spectral type A8III[3] or A7IV[4]
B−V color index 0.250±0.004[2]
Astrometry
Radial velocity (Rv)−10.9±2.9[2] km/s
Proper motion (μ) RA: +75.736[1] mas/yr
Dec.: +16.724[1] mas/yr
Parallax (π)10.3023 ± 0.0957 mas[1]
Distance317 ± 3 ly
(97.1 ± 0.9 pc)
Absolute magnitude (MV)0.52[2]
Details
Mass2.25?[5] M☉
Radius3.98+0.11
−0.13[1] R☉
Luminosity44.3±0.5[1] L☉
Temperature7466+217
−105[1] K
Rotational velocity (v sin i)110[4] km/s
Age~900[5] Myr
Other designations
BD+86°3444, HD 221525, HIP 115746, HR 8938, SAO 3916[6]
Database references
SIMBADdata

HD 221525 is a single[7] star near the north celestial pole[5] in the constellation Cepheus. At an apparent magnitude of 5.56,[2] it can be seen with the naked eye under dark skies. It is about 30 times fainter than the nearby prominent star Polaris.[8] Based upon parallax measurements, HD 221525 is located at a distance of approximately 317 light years from the Sun,[1] but is drifting closer with a radial velocity of −11 km/s.[2]

This object is an A-type star with a stellar classification of A7IV[4] or A8III,[3] suggesting it is an evolving star on the subgiant or giant branch, respectively. It has a relatively high rate of spin, showing a projected rotational velocity of 110 km/s.[4] The star has four[1] times the radius of the Sun and is radiating 44[1] times the Sun's luminosity from its photosphere at an effective temperature of 7,466 K.[1]

  1. ^ a b c d e f g h i j k l Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference abt1995 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Cowley1974 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference KALER was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference SIMBAD 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 mag was invoked but never defined (see the help page).