Astronomy:Theta1 Orionis D
280px Theta1 Orionis D and companions in the Trapezium cluster | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Orion |
| Right ascension | 05h 35m 17.24645s[1] |
| Declination | −05° 23′ 16.5707″[1] |
| Apparent magnitude (V) | 6.70[2] |
| Characteristics | |
| Spectral type | B1.5V + B[3] |
| U−B color index | −0.71[2] |
| B−V color index | +0.09[2] |
| Astrometry | |
| Radial velocity (Rv) | +32.4[4] km/s |
| Proper motion (μ) | RA: +1.822[1] mas/yr Dec.: −0.393[1] mas/yr |
| Parallax (π) | 2.2820 ± 0.0207[1] mas |
| Distance | 1,430 ± 10 ly (438 ± 4 pc) |
| Absolute magnitude (MV) | −3.3[5] |
| Orbit[3] | |
| Primary | θ1 Orionis D1 |
| Companion | θ1 Orionis D3 |
| Period (P) | 0.1452 ± 0.0002 years (53.034 ± 0.073 days) |
| Semi-major axis (a) | (1.86±0.06)×10−3" (0.77±0.03 au) |
| Eccentricity (e) | 0.43±0.03 |
| Inclination (i) | 160±12° |
| Longitude of the node (Ω) | 346±24° |
| Periastron epoch (T) | 2017.101±0.001 |
| Argument of periastron (ω) (secondary) | 166±27° |
| Details | |
| θ1 Orionis D1 | |
| Mass | 16±1[3] M☉ |
| Radius | 5.6±0.8[5] R☉ |
| Luminosity | 29,500[5] L☉ |
| Surface gravity (log g) | 4.2±0.1[5] cgs |
| Temperature | 32,000±1,000[5] K |
| Rotational velocity (v sin i) | 49.0±0.9[5] km/s |
| Age | 2.5±0.5[5] Myr |
| θ1 Orionis D3 | |
| Mass | 6±1[3] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
Theta1 Orionis D (θ1 Orionis D) is a binary star system that is part of the Trapezium open cluster that lies within the Orion Nebula.
θ1 Orionis consists of multiple components, primarily the four stars of the Trapezium cluster (A, B, C, and D) all within one arc-minute of each other. θ2 Orionis is a more distant grouping of three main stars plus several fainter companions, 1-2 arc-minutes from θ1.
Characteristics
θ1 D is a spectroscopic binary with an orbital period of 53.03±0.07 d. The two components are named θ1 Orionis D1 and θ1 Orionis D3. D1 is a B-type main-sequence star of spectral type B1.5V and a mass 16 times that of the Sun. D3 is a B-type star, with a mass six times solar and a brightness 1.15 times fainter than the primary in the K-band.[3]
There is a more widely-separated companion 1.4" away (projected separation of 580±10 au), although it is not confirmed to be gravitationally bound. It has an estimated mass of 1.1±0.1 M☉.[3] Infrared Optical Telescope Array observations suggest another companion at 18.6 mas,[6] which was not confirmed with GRAVITY observations.[3]
References
- ↑ 1.0 1.1 1.2 1.3 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues 2237: 0. Bibcode: 2002yCat.2237....0D.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 GRAVITY Collaboration; Karl, Martina; Pfuhl, Oliver; Eisenhauer, Frank; Genzel, Reinhard; Grellmann, Rebekka; Habibi, Maryam; Abuter, Roberto et al. (2018-12-01). "Multiple star systems in the Orion nebula". Astronomy and Astrophysics 620: A116. doi:10.1051/0004-6361/201833575. ISSN 0004-6361. Bibcode: 2018A&A...620A.116G.
- ↑ Olivares, J.; Sánchez, L. J.; Ruelas-Mayorga, A.; Allen, C.; Costero, R.; Poveda, A. (2013). "Kinematics of the Orion Trapezium Based on Diffracto-Astrometry and Historical Data". The Astronomical Journal 146 (5): 106. doi:10.1088/0004-6256/146/5/106. Bibcode: 2013AJ....146..106O.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 Simón-Díaz, S.; Herrero, A.; Esteban, C.; Najarro, F. (2006). "Detailed spectroscopic analysis of the Trapezium cluster stars inside the Orion nebula". Astronomy and Astrophysics 448 (1): 351–366. doi:10.1051/0004-6361:20053066. ISSN 0004-6361. Bibcode: 2006A&A...448..351S.
- ↑ Grellmann, R.; Preibisch, T.; Ratzka, T.; Kraus, S.; Helminiak, K. G.; Zinnecker, H. (2013). "The multiplicity of massive stars in the Orion Nebula Cluster as seen with long-baseline interferometry". Astronomy & Astrophysics 550: A82. doi:10.1051/0004-6361/201220192. Bibcode: 2013A&A...550A..82G.
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