Pi Tucanae

Pi Tucanae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Tucana
Right ascension 0h 20m 39.03682s[1]
Declination −69° 37′ 29.6821″[1]
Apparent magnitude (V) +5.49[2]
Characteristics
Spectral type B9 V[3]
U−B color index −0.11[2]
B−V color index −0.05[2]
Astrometry
Radial velocity (Rv)+10.50±2.60[4] km/s
Proper motion (μ) RA: −3.53[1] mas/yr
Dec.: −0.10[1] mas/yr
Parallax (π)10.25 ± 0.21 mas[1]
Distance318 ± 7 ly
(98 ± 2 pc)
Absolute magnitude (MV)+0.57[5]
Details
π Tuc A
Mass2.8+0.21
−0.18[6] M☉
Luminosity59[7] L☉
Surface gravity (log g)4.0±0.14[6] cgs
Temperature11,393±387[6] K
Rotational velocity (v sin i)236[8] km/s
Age206+48
−79[6] Myr
π Tuc B
Mass0.60[5] M☉
Radius0.553[5][a] R☉
Luminosity0.063[5] L☉
Temperature3,890[5] K
Other designations
π Tuc, CPD−70° 12, FK5 2018, HD 1685, HIP 1647, HR 83, SAO 248167[9]
Database references
SIMBADdata

Pi Tucanae (π Tuc, π Tucanae) is a double star[5] in the southern constellation of Tucana. It is visible to the naked eye with a combined apparent visual magnitude of +5.49.[2] Based upon an annual parallax shift of 10.25 mas as seen from Earth, it is located around 317 light years from the Sun.

The brighter star, component A, is a B-type main sequence star with a stellar classification of B9 V.[3] At an age of about 206 million years,[6] it is spinning rapidly with a projected rotational velocity of 236.[8] The star has an estimated 2.8[6] times the mass of the Sun and radiates 59[7] times the solar luminosity from its photosphere at an effective temperature of 11,393 K.[6]

There is a nearby visual companion, component B, but the two stars may not form a physical pair. This star has a K-band magnitude of 10.1 and is a source of X-ray emission. It has 60% of the Sun's mass and just 6.3% of the Sun's luminosity, with an effective temperature of 3,890 K.[5] The pair have an angular separation of 2.28 arc seconds along a position angle of 211.4°, which corresponds to a projected separation of 214.1 AU.[5]

  1. ^ a b c d e Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Cousins1971 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference houk1979 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  5. ^ a b c d e f g h Cite error: The named reference Hubrig2001 was invoked but never defined (see the help page).
  6. ^ a b c d e f g Cite error: The named reference Kraus2016 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Royer2007 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).


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