HD 2942
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda[1] |
| A | |
| Right ascension | Template:RA[2] |
| Declination | Template:DEC[2] |
| Apparent magnitude (V) | 6.33[3] |
| B | |
| Right ascension | Template:RA[4] |
| Declination | Template:DEC[4] |
| Apparent magnitude (V) | 11.26[5] |
| Characteristics | |
| Spectral type | K0III+G6V+G8V[5] |
| U−B Template:Engvar | 0.80[3] |
| B−V Template:Engvar | 0.99[3] |
| Astrometry | |
| A | |
| Radial velocity (Rv) | Script error: No such module "val".[2] km/s |
| Proper motion (μ) | RA: Script error: No such module "val".[2] mas/yr Dec.: Script error: No such module "val".[2] mas/yr |
| Parallax (π) | 5.8690±0.0434 mas[2] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Orbit[5] | |
| Primary | HD 2942Ba |
| Companion | HD 2942Bb |
| Period (P) | 7.4887 days |
| Eccentricity (e) | 0.055 |
| Periastron epoch (T) | HJD 2,451,060.5586 |
| Argument of periastron (ω) (secondary) | 293.40° |
| Semi-amplitude (K1) (primary) | 64.01 km/s |
| Semi-amplitude (K2) (secondary) | 66.34 km/s |
| Details[5] | |
| HD 2942A | |
| Mass | 3.17 Template:Solar mass |
| HD 2942B | |
| Mass | 0.89 (Ba) 0.85 (Bb) Template:Solar mass |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| Other designations | |
| HIP 2583, HR 134, BD+27°84, SAO 74090, WDS J00328+2817A | |
| Database references | |
| SIMBAD | A |
| B | |
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HD 2942 is a triple star system[5] in the constellation Andromeda located approximately Script error: No such module "convert". away.
The primary component, a red giant of spectral type K0III, has an apparent magnitude of 6.33, meaning that it is barely visible with the naked eye under good conditions.[3]
The secondary component is much fainter, with an apparent magnitude 11.26, and is located 8.6 arcseconds away. It is a double-lined spectroscopic binary, where two very similar G-type main sequence stars of spectral types G6V and G8V orbit around their common center of mass in 7.489 days. The pair complete an orbit around the primary star every 24,762 years.[5]
Catalogues of stellar multiplicity, like the Washington Double Star Catalog, usually list another component; this star, however, is located much more far away than the other two.[6]
References
<templatestyles src="Reflist/styles.css" />
- ↑ Template:Cite constellation
- ↑ a b c d e f Template:Cite DR2
- ↑ a b c d Database entry, Catalogue of Stellar Photometry in Johnson's 11-color system (2002 Ed.), J. R. Ducati, CDS ID II/237 Accessed on line 2018-12-05.
- ↑ a b Template:Cite Gaia DR3
- ↑ a b c d e f Database entry, VizieR Online Data Catalog: Updated Multiple Star Catalog (MSC) (Tokovinin 2018), A. Tokovinin, CDS ID J/ApJS/235/6 Accessed on line 2018-11-29.
- ↑ Template:Cite simbad
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