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] |
Distance | 251 ± 9 ly (77 ± 3 pc) |
Absolute magnitude (MV) | A: 0.20, B: 4.50[3] |
Details | |
δ Tuc A | |
Mass | 2.99[4] M☉ |
Radius | 2.7[5] R☉ |
Surface gravity (log g) | 4.11±0.14[4] cgs |
Temperature | 11,271±383[4] K |
Rotation | 2.8535[6] d |
Rotational velocity (v sin i) | 224[7] km/s |
Age | 232[4] Myr |
Other designations | |
Database references | |
SIMBAD | data |
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.
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 Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode:1978A&AS...34....1N.
- ^ a b c d e f g h i j Corbally, C. J. (1984), "Close visual binaries. I - MK classifications", Astrophysical Journal Supplement Series, 55: 657, Bibcode:1984ApJS...55..657C, doi:10.1086/190973.
- ^ a b c d e David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
- ^ Pasinetti Fracassini, L. E.; Pastori, L.; Covino, S.; Pozzi, A. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (3rd ed.): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
- ^ 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.
- ^ a b Royer, F.; et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics, 393: 897–911, arXiv:astro-ph/0205255, Bibcode:2002A&A...393..897R, doi:10.1051/0004-6361:20020943, S2CID 14070763.
- ^ "del Tuc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-04-22.
{{cite web}}
: CS1 maint: postscript (link) - ^ Streicher, Magda (2005), "Deepsky Delights", Monthly Notes of the Astronomical Society of Southern Africa, 64 (9–10): 172–74, Bibcode:1907GOAMM..67G...2C.
- ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.
- ^ 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.