Astronomy:Delta Tucanae
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| Observation data 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[1] mas |
| 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 of stars 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
- ↑ 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 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.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 Corbally, C. J. (1984), "Close visual binaries. I - MK classifications", Astrophysical Journal Supplement Series 55: 657, doi:10.1086/190973, Bibcode: 1984ApJS...55..657C.
- ↑ 4.0 4.1 4.2 4.3 4.4 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, doi:10.1088/0004-637X/804/2/146, Bibcode: 2015ApJ...804..146D.
- ↑ 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: 521–524, doi:10.1051/0004-6361:20000451, Bibcode: 2001A&A...367..521P.
- ↑ 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. et al. (2022). "Rotation Signature of TESS B-type Stars. A Comprehensive Analysis". The Astrophysical Journal 924 (2): 117. doi:10.3847/1538-4357/ac3335. Bibcode: 2022ApJ...924..117B.
- ↑ 7.0 7.1 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, doi:10.1051/0004-6361:20020943, Bibcode: 2002A&A...393..897R.
- ↑ "del Tuc". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=del+Tuc.
- ↑ 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, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M.
- ↑ Belle, G. T. (2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review 20 (1), doi:10.1007/s00159-012-0051-2, Bibcode: 2012A&ARv..20...51V.
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