Pi Aurigae

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Pi Aurigae
The location of π Aurigae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Auriga[1]
Right ascension 05h 59m 56.09792s[2]
Declination +45° 56′ 12.2457″[2]
Apparent magnitude (V) 4.25[3]
Characteristics
Evolutionary stage asymptotic giant branch[4]
Spectral type M3 IIb[5]
U−B color index +1.83[3]
B−V color index +1.72[3]
Variable type LC[6]
Astrometry
Radial velocity (Rv)0.71±0.76[7] km/s
Proper motion (μ) RA: −3.755 mas/yr[2]
Dec.: −7.785 mas/yr[2]
Parallax (π)4.515±0.241 mas[2]
Distance720 ± 40 ly
(220 ± 10 pc)
Absolute magnitude (MV)−2.46[1]
Details
Mass2.98[8] M
Radius218.6[9] R
Luminosity6,630±1,054[9] L
Surface gravity (log g)0.55±0.10[10] cgs
Temperature3,525±125[9] K
Metallicity [Fe/H]0.03±0.04[10] dex
Other designations
π Aur, 35 Aurigae, BD+45 1217, HD 40239, HIP 28404, HR 2091, SAO 40756[11]
Database references
SIMBADdata
File:Pi Aurigae.jpg
π Aurigae (center) in optical light

Pi Aurigae is a single,[12] red-hued star in the northern constellation of Auriga. Its name is a Bayer designation that is Latinized from π Aurigae, and abbreviated Pi Aur or π Aur. Located about one degree north of the 2nd magnitude star Beta Aurigae,[13] Pi Aurigae is visible to the naked eye with an apparent visual magnitude of 4.25[3] Based upon parallax measurements, it is approximately 720 light-years (220 parsecs) away from Earth.[2] At that distance, the brightness of the star is diminished by 0.54 in magnitude from extinction caused by interstellar gas and dust.[7]

Pi Aurigae is an evolved bright giant star with a stellar classification of M3 IIb.[5] After exhausting the supply of hydrogen at its core the star has expanded to approximately 219 times the size of the Sun.[9] It is classified as a slow irregular variable of type LC and its brightness varies from magnitude +4.24 to +4.34.[6] On average, the star is radiating 6,630 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,525 K.[9]

References

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  1. ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). XHIP record for this object at VizieR.
  2. ^ a b c d e Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). Gaia DR3 record for this source at VizieR.
  3. ^ a b c d Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  4. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  5. ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  6. ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  7. ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  8. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  9. ^ a b c d e Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). Pi Aurigae's database entry at VizieR.
  10. ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  11. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  12. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  13. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
[edit | edit source]