Binary star in the constellation Triangulum
Delta Trianguli Location of δ Trianguli (circled)
Observation dataEpoch 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−Bcolor index +0.02[ 4] B−Vcolor 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 pc ) Absolute magnitude (MV )4.69[ 2] Orbit [ 6] Companion Delta Trianguli B Period (P)10.02 days Semi-major axis (a)± 0.06 masEccentricity (e)± 0.005Inclination (i)± 3Longitude of the node (Ω)± 9Details A Mass ± 0.059[ 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] [ 9] dex Rotational velocity (v sin i )10.00[ 5] Age 8.5[ 10] [ 2] Gyr B Mass ± 0.044[ 7] M ☉ Temperature 4,493[ 3] K Other designations Deltoton,δ Tri, Delta Tri ,8 Trianguli ,BD +33°395GJ 92HD 13974HIP 10644HR 660SAO 55420LHS 154LTT 10770[ 11] Database references SIMBAD data
Delta Trianguli , (also namedDeltoton for component A),[ 12] spectroscopic binary star system approximately 35light-years (11 pc ) away in theconstellation ofTriangulum . The primarystar is ayellow dwarf , while the secondary star is thought to be anorange dwarf . It has anapparent magnitude of +4.87 and forms an optical (line-of-sight) triple withGamma Trianguli and7 Trianguli .[ 13]
Delta Trianguli,Latinized from δ Trianguli and abbreviated Delta Tri, is the star'sBayer designation .
Deltoton was an ancient Greek name of the constellation Triangulum, so named because the capital Greek letterdelta is shaped like a triangle.[ 14] IAU Working Group on Star Names approved the name Deltoton for this star on 17 June 2025 and it is now so entered in the IAU Catalog of Star Names.[ 12] [ 15]
InChinese ,天大將軍 Tiān Dà Jiāng Jūn Heaven's Great General γ Andromedae ,φ Persei ,51 Andromedae ,49 Andromedae ,χ Andromedae ,υ Andromedae ,τ Andromedae ,56 Andromedae ,β Trianguli andγ Trianguli . Consequently, theChinese name for δ Trianguli itself is天大將軍十一 Tiān Dà Jiāng Jūn shíyī the Eleventh Star of Heaven's Great General ).[ 16]
Delta Trianguli A is amain sequence star with astellar classification of G0V and a mass similar to theSun .[ 13] [ 17] [ 3] center of mass with an estimated separation of 0.106 AU ;[ 13] [ 3] days and theeccentricity 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 anadaptive optics system on theVLT proved unsuccessful.[ 18] excess emission that would otherwise indicate the presence of a disk of orbiting dust.[ 3]
^a b c d e 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 . ^a b c d 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 ^a b c d e f 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 ^a b 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 ^a b 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 ^a b "Sixth Catalog of Orbits of Visual Binary Stars" ,U.S. Naval Observatory , archived fromthe original on 2009-04-12, retrieved2008-06-22 ^a b 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 ^a b 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 , retrieved2011-09-16 ^a b "IAU Catalog of Star Names" . Retrieved17 June 2025 .^a b c Kaler, James ,"Delta Tri" ,Stars: Portraits of Stars and their Constellations ,University of Illinois , retrieved2011-09-16 ^ Ridpath, Ian ."Star Tales - Triangulum" . Retrieved17 June 2025 .^ "Deltoton (Δελτωτόν)" .All Skies Encyclopaedia .IAU Working Group on Star Names . Retrieved17 June 2025 .^ (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 theWayback Machine ^ 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
