Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Triangulum |
Right ascension | 02h 17m 03.23016s [1] |
Declination | +34° 13′ 27.2260″ [1] |
Apparent magnitude (V) | +4.865 [2] |
Characteristics | |
Spectral type | G0V + G9V to K4V [3] |
U−B color index | +0.02 [4] |
B−V color index | +0.61 [4] |
Astrometry | |
Radial velocity (Rv) | −5.70 [5] km/s |
Proper motion (μ) |
RA: 1151.83
[1]
mas/
yr Dec.: −246.89 [1] mas/ yr |
Parallax (π) | 92.73 ± 0.39 mas [1] |
Distance | 35.2 ± 0.1
ly (10.78 ± 0.05 pc) |
Absolute magnitude (MV) | 4.69 [2] |
Orbit [6] | |
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 | 1.0 [7] M☉ |
Radius | 0.98 [8] R☉ |
Surface gravity (log g) | 4.5 [9] cgs |
Temperature | 6,215 [3] K |
Metallicity [Fe/H] | −0.39 [2] to −0.30 [9] dex |
Rotational velocity (v sin i) | 10.00 [5] km/s |
Age | 8.5 [10] to 9.0 [2] Gyr |
B | |
Mass | 0.8 [7] M☉ |
Temperature | 4,493 [3] K |
Other designations | |
δ Tri, Delta Tri,
8 Trianguli,
BD+33° 395,
HD 13974,
HIP 10644,
HR 660,
SAO 55420,
LHS 154,
LTT 10770
[11] | |
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. [7]
Delta Trianguli A is a main sequence star with a stellar classification of G0V and a mass similar to the Sun. [7] The spectral characteristics of the smaller companion Delta Trianguli B are not well determined since the close orbit makes observations difficult, [12] with estimates of the spectral class ranging from G9V to K4V. [3] The Delta Trianguli stars orbit their center of mass with an estimated separation of 0.106 AU; [7] it is certainly less than one AU. [3] 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. [6]
A 2008 search for a tertiary companion to this system using an adaptive optics system on the VLT proved unsuccessful. [13] 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. [3]
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.). [14]