Delta Tucanae

Delta Tucanae A/B
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Tucana
Right ascension 22h 27m 19.96745s[1]
Declination −64° 57′ 58.8775″[1]
Apparent magnitude (V) +4.48[2] (A: 4.52, B: 8.85)[3]
Characteristics
Spectral type B9 Vn + G0 V Fe−2[3]
U−B color index A: −0.07, B: −0.02[3]
B−V color index A: −0.02, B: +0.51[3]
Astrometry
Proper motion (μ) RA: +68.45[1] mas/yr
Dec.: +10.06[1] mas/yr
Parallax (π)13.00 ± 0.48 mas[1]
Distance251 ± 9 ly
(77 ± 3 pc)
Absolute magnitude (MV)A: 0.20, B: 4.50[3]
Details
δ Tuc A
Mass2.99[4] M☉
Radius2.7[5] R☉
Surface gravity (log g)4.11±0.14[4] cgs
Temperature11,271±383[4] K
Rotation2.8535[6] d
Rotational velocity (v sin i)224[7] km/s
Age232[4] Myr
Other designations
δ Tuc, CP−65° 4044, HD 212581, HIP 110838, HR 8540, SAO 255222, WDS J22273-6458AB[8]
Database references
SIMBADdata

Delta Tucanae (δ Tuc, δ Tucanae) is a common proper motion[3] pair located in the southwestern corner of the southern constellation of Tucana.[9] Based upon an annual parallax shift of 13.00 mas as seen from Earth, is approximately 250 light years from the Sun. It is visible to the naked eye with a combined apparent visual magnitude of +4.48.[2] As of 2013, the two components had an angular separation of 7.0 arc seconds along a position angle of 282°.[10]

The brighter primary, component A, is blue-white hued star a visual magnitude of 4.52.[3] It is a B-type main-sequence star with a stellar classification of B9 Vn,[3] where the 'n' suffix indicates "nebulous" absorption lines due to the star's rotation. It is spinning rapidly with a projected rotational velocity of 224 km/s,[7] which is giving the star an oblate shape with an equatorial bulge that is an estimated 12% larger than the polar radius.[11] The star has about three times the mass of the Sun and is around 232 million years old.[4]

The magnitude 8.85[3] companion, component B, is a G-type main-sequence star. It has a classification of G0 V Fe−2,[3] with the suffix indicating an underabundance of iron in the star's photosphere.

  1. ^ a b c d e Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Nicolet1978 was invoked but never defined (see the help page).
  3. ^ a b c d e f g h i j Cite error: The named reference corbally1984 was invoked but never defined (see the help page).
  4. ^ a b c d e Cite error: The named reference David2015 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference PasinettiFracassini2001 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Barraza was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Royer2002 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference striecher 2005 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).
  11. ^ Cite error: The named reference belle2012 was invoked but never defined (see the help page).