Location of δ Trianguli (circled) | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Triangulum |
| Right ascension | 02 17 03.23016 |
| Declination | +34° 13′ 27.2260″ |
| Apparent magnitude (V) | +4.865 |
| Characteristics | |
| Spectral type | G0V + G9V to K4V |
| U−B color index | +0.02 |
| B−V color index | +0.61 |
| Astrometry | |
| Radial velocity (Rv) | −5.70 km/s |
| Proper motion (μ) | RA: 1151.83 mas/yr Dec.: −246.89 mas/yr |
| Parallax (π) | 92.73 ± 0.39 mas |
| Distance | 35.2 ± 0.1 ly (10.78 ± 0.05 pc) |
| Absolute magnitude (MV) | 4.69 |
| Orbit | |
| Companion | Delta Trianguli B |
| Period (P) | 10.02 days |
| Semi-major axis (a) | 9.80±0.06 mas |
| Eccentricity (e) | 0.020±0.005 |
| Inclination (i) | 167±3° |
| Longitude of the node (Ω) | 15±9° |
| Details | |
| A | |
| Mass | 0.884±0.059 M☉ |
| Radius | 0.98 R☉ |
| Surface gravity (log g) | 4.5 cgs |
| Temperature | 6,215 K |
| Metallicity | −0.39 to −0.30 dex |
| Rotational velocity (v sin i) | 10.00 km/s |
| Age | 8.5 to 9.0 Gyr |
| B | |
| Mass | 0.785±0.044 M☉ |
| Temperature | 4,493 K |
| Other designations | |
| δ Tri, Delta Tri, 8 Trianguli, BD+33° 395, HD 13974, HIP 10644, HR 660, SAO 55420, LHS 154, LTT 10770 | |
| Database references | |
| SIMBAD | data |
Delta Trianguli, Latinized from Delta Tri, is a spectroscopic binary star system approximately 35 light-years (11 pc) away in the constellation of Triangulum. The primary star is a yellow dwarf, while the secondary star is thought to be an orange dwarf. It has an apparent magnitude of +4.87 and forms an optical (line-of-sight) triple with Gamma Trianguli and 7 Trianguli.
Stellar components
Delta Trianguli A is a main sequence star with a stellar classification of G0V and a mass similar to the Sun. The spectral characteristics of the smaller companion Delta Trianguli B are not well determined since the close orbit makes observations difficult, with estimates of the spectral class ranging from G9V to K4V. The Delta Trianguli stars orbit their center of mass with an estimated separation of 0.106 AU; it is certainly less than one AU. The orbital period is 10.02 days and the eccentricity of the orbit is only 0.020. The orbit is inclined about 167° to the line of sight from Earth.
A 2008 search for a tertiary companion to this system using an adaptive optics system on the VLT proved unsuccessful. Examination of the system in infrared light at 70 μm shows no excess emission that would otherwise indicate the presence of a disk of orbiting dust.
Naming
In Chinese, 天大將軍 (Tiān Dà Jiāng Jūn), meaning Heaven's Great General, refers to an asterism consisting of δ Trianguli γ Andromedae, φ Persei, 51 Andromedae, 49 Andromedae, χ Andromedae, υ Andromedae, τ Andromedae, 56 Andromedae, β Trianguli and γ Trianguli. Consequently, the Chinese name for δ Trianguli itself is 天大將軍十一 (Tiān Dà Jiāng Jūn shíyī, English: the Eleventh Star of Heaven's Great General.).
See also
References
- ^ van Leeuwen, F. (November 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.
- ^ Nordström, B.; et al. (May 2004), "The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ˜14 000 F and G dwarfs", Astronomy and Astrophysics, 418: 989–1019, arXiv:astro-ph/0405198, Bibcode:2004A&A...418..989N, doi:10.1051/0004-6361:20035959, S2CID 11027621
- ^ Kim, Jinyoung Serena; et al. (October 2005), "Formation and Evolution of Planetary Systems: Cold Outer Disks Associated with Sun-like Stars", The Astrophysical Journal, 632 (1): 659–669, arXiv:astro-ph/0506434, Bibcode:2005ApJ...632..659K, doi:10.1086/432863, S2CID 7324203
- ^ Johnson, H. L.; Iriarte, B.; Mitchell, R. I.; Wisniewskj, W. Z. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J
- ^ White, Russel J.; et al. (June 2007), "High-Dispersion Optical Spectra of Nearby Stars Younger Than the Sun", The Astronomical Journal, 133 (6): 2524–2536, arXiv:0706.0542, Bibcode:2007AJ....133.2524W, doi:10.1086/514336, S2CID 122854
- ^ "Sixth Catalog of Orbits of Visual Binary Stars", U.S. Naval Observatory, archived from the original on 2009-04-12, retrieved 2008-06-22
- ^ Piccotti, Luca; Docobo, José Ángel; Carini, Roberta; Tamazian, Vakhtang S; Brocato, Enzo; Andrade, Manuel; Campo, Pedro P (2020-01-03). "A study of the physical properties of SB2s with both the visual and spectroscopic orbits". Monthly Notices of the Royal Astronomical Society. 492 (2). Oxford University Press (OUP): 2709–2721. Bibcode:2020MNRAS.492.2709P. doi:10.1093/mnras/stz3616. ISSN 0035-8711.
- Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy and Astrophysics, 367 (2): 5211–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754
- ^ Clegg, R. E. S. (October 1977), "Carbon and nitrogen abundances in F- and G-type stars", Monthly Notices of the Royal Astronomical Society, 181: 1–30, Bibcode:1977MNRAS.181....1C, doi:10.1093/mnras/181.1.1
- Holmberg, J.; Nordström, B.; Andersen, J. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191, S2CID 118577511
- "del Tri -- Spectroscopic binary", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2011-09-16
- ^ Kaler, James, "Delta Tri", Stars: Portraits of Stars and their Constellations, University of Illinois, retrieved 2011-09-16
- Raghavan, Deepak; et al. (September 2010), "A Survey of Stellar Families: Multiplicity of Solar-type Stars", The Astrophysical Journal Supplement, 190 (1): 1–42, arXiv:1007.0414, Bibcode:2010ApJS..190....1R, doi:10.1088/0067-0049/190/1/1, S2CID 368553
- Tokovinin, A.; et al. (May 2006), "Tertiary companions to close spectroscopic binaries", Astronomy and Astrophysics, 450 (2): 6811–693, arXiv:astro-ph/0601518, Bibcode:2006A&A...450..681T, doi:10.1051/0004-6361:20054427, S2CID 8899546
- (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 10 日 Archived 2011-07-16 at the Wayback Machine
External links
- "Delta Trianguli 2". SolStation. Retrieved 2008-06-22.
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