Phi Tauri

Phi Tauri
Location of φ Tauri (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Taurus
Right ascension 04h 20m 21.21580s[1]
Declination +27° 21′ 02.7009″[1]
Apparent magnitude (V) +4.957[2]
Characteristics
Spectral type K1 III[2]
B−V color index 1.154[2]
Astrometry
Radial velocity (Rv)1.27[2] km/s
Proper motion (μ) RA: −28.90[1] mas/yr
Dec.: −78.28[1] mas/yr
Parallax (π)10.16 ± 0.26 mas[1]
Distance321 ± 8 ly
(98 ± 3 pc)
Absolute magnitude (MV)−0.15[3]
Details[4]
Mass1.36±0.19 M☉
Radius19.04±0.56 R☉
Luminosity131.0±6.8 L☉
Surface gravity (log g)2.02±0.08 cgs
Temperature4,479±30 K
Metallicity [Fe/H]−0.32±0.10 dex
Rotational velocity (v sin i)1.0[5] km/s
Age4.74±2.56 Gyr
Other designations
φ Tau, 52 Tauri, BD+27° 655, HD 27382, HIP 20250, HR 1348, SAO 76558, ADS 3137, WDS J04204+2721A[6]
Database references
SIMBADdata

Phi Tauri (φ Tauri) is a solitary,[7] orange-hued star in the zodiac constellation of Taurus. It has an apparent visual magnitude of +4.96,[2] which indicates the star is faintly visible to the naked eye. Based upon an annual parallax shift of 10.16 mas as seen from Earth,[1] it is located roughly 321 light years distant from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.27 due to interstellar dust.[8]

This is an evolved, K-type giant star with a stellar classification of K1 III,[2] currently (97% probability) on the red giant branch. It has an estimated 1.36 times the mass of the Sun and has expanded to 19 times the Sun's radius. At the age of roughly five billion years, it is radiating 131 times the Sun's luminosity from its inflated photosphere at an effective temperature of 4,479 K.[4]

Phi Tauri has a magnitude 7.51 visual companion located at an angular separation of 48.80 arc seconds along a position angle of 258°, as of 2015. The pair form a yellow and blue double that is visible in small telescopes.[9] A fainter, magnitude 12.27 companion lies at a separation of 118.10 arc seconds along a position angle of 25°, as of 2001.[10]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference Luck2015 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Luck2007 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Reffert2015 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference DeMedeiros2000 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 Famaey2005 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Privett2013 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).