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Star in the constellation Tucana
Epsilon Tucanae (ε Tuc, ε Tucanae) is a solitary
[9]
star in the southern
constellation of
Tucana . With an
apparent visual magnitude of +4.50,
[2] it is faintly visible to the naked eye. Based upon an annual
parallax shift of 8.74
mas as seen from Earth, it is located around 373
light years from the
Sun .
Levenhagen and Leister (2008)
classified this star as B8 V,
[3] indicating a blue-white hued
B-type main sequence star . However, Hiltner, Garrison, and Schild (1969) listed it with a classification of B9 IV,
[4] suggesting it may be a more
evolved
subgiant star . It is a rapidly rotating
Be star that is an estimated 78% of the way through its
main sequence lifetime.
[10] The
projected rotational velocity is 300 km/s,
[3] which is giving it an
oblate shape with an
equatorial bulge that is an estimated 36% larger than the polar radius.
[11] It has a weak
magnetic field with a strength of 74± 24
G .
[12]
It is the last star in the
Hipparcos catalogue , HIP 118322, from the
Hipparcos (1989–1993) astrometry satellite.
References
^
a
b
c
d
e van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics , 474 (2): 653–664,
arXiv :
0708.1752 ,
Bibcode :
2007A&A...474..653V ,
doi :
10.1051/0004-6361:20078357 ,
S2CID
18759600 .
^
a
b
c
d Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory , 4 (99): 99,
Bibcode :
1966CoLPL...4...99J .
^
a
b
c
d
e
f
g
h
i Levenhagen, R. S.; Leister, N. V. (2006), "Spectroscopic Analysis of Southern B and Be Stars",
Monthly Notices of the Royal Astronomical Society , 371 (1): 252–62,
arXiv :
astro-ph/0606149 ,
Bibcode :
2006MNRAS.371..252L ,
doi :
10.1111/j.1365-2966.2006.10655.x ,
S2CID
16492030 .
^
a
b Hiltner, W. A.; et al. (July 1969), "MK Spectral Types for Bright Southern OB Stars", Astrophysical Journal , 157 : 313,
Bibcode :
1969ApJ...157..313H ,
doi :
10.1086/150069 .
^ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters , 32 (11): 759–771,
arXiv :
1606.08053 ,
Bibcode :
2006AstL...32..759G ,
doi :
10.1134/S1063773706110065 ,
S2CID
119231169 .
^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters , 38 (5): 331,
arXiv :
1108.4971 ,
Bibcode :
2012AstL...38..331A ,
doi :
10.1134/S1063773712050015 ,
S2CID
119257644 .
^ Barraza, L. F.; Gomes, R. L.; Messias, Y. S.; Leão, I. C.; Almeida, L. A.; Janot-Pacheco, E.; Brito, A. C.; Brito, F. A. C.; Santana, J. V.; Gonçalves, N. S.; Das Chagas, M. L.; Teixeira, M. A.; De Medeiros, J. R.; Canto Martins, B. L. (2022).
"Rotation Signature of TESS B-type Stars. A Comprehensive Analysis" . The Astrophysical Journal . 924 (2): 117.
arXiv :
2202.01022 .
Bibcode :
2022ApJ...924..117B .
doi :
10.3847/1538-4357/ac3335 .
S2CID
246030494 .
^
"eps Tuc -- Be Star" , SIMBAD Astronomical Database ,
Centre de Données astronomiques de Strasbourg , retrieved 2017-04-22 .
^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems",
Monthly Notices of the Royal Astronomical Society , 389 (2): 869–879,
arXiv :
0806.2878 ,
Bibcode :
2008MNRAS.389..869E ,
doi :
10.1111/j.1365-2966.2008.13596.x ,
S2CID
14878976 .
^ Zorec, J.; et al. (October 2005), "On the evolutionary status of Be stars. I. Field Be stars near the Sun", Astronomy and Astrophysics , 441 (1): 235–248,
arXiv :
astro-ph/0509119 ,
Bibcode :
2005A&A...441..235Z ,
doi :
10.1051/0004-6361:20053051 ,
S2CID
17592657 .
^ Belle, G. T. (2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review , 20 (1): 51,
arXiv :
1204.2572 ,
Bibcode :
2012A&ARv..20...51V ,
doi :
10.1007/s00159-012-0051-2 ,
S2CID
119273474 .
^ Hubrig, S.; et al. (July 2009), "Magnetic survey of emission line B-type stars with FORS 1 at the VLT", Astronomische Nachrichten , 330 (7): 708,
arXiv :
0907.0882 ,
Bibcode :
2009AN....330..708H ,
doi :
10.1002/asna.200911236 ,
S2CID
13620067 .