Astronomy:Chi Eridani
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Eridanus |
| Right ascension | 01h 55m 57.45606s[1] |
| Declination | −51° 36′ 31.9736″[1] |
| Apparent magnitude (V) | 3.70[2] / 10.7[3] |
| Characteristics | |
| Spectral type | G8IV[4] or G8IIIb CNIV[5] |
| U−B color index | +0.46[2] |
| B−V color index | +0.85[2] |
| Astrometry | |
| Radial velocity (Rv) | –6.30[6] km/s |
| Proper motion (μ) | RA: +682.281[1] mas/yr Dec.: −295.332[1] mas/yr |
| Parallax (π) | 57.3774 ± 0.3291[1] mas |
| Distance | 56.8 ± 0.3 ly (17.43 ± 0.10 pc) |
| Absolute magnitude (MV) | 2.39 / 9.4[3] |
| Details[7] | |
| A | |
| Mass | 1.58[8] M☉ |
| Radius | 3.993±0.027 R☉ |
| Luminosity | 9.84±0.39 L☉ |
| Surface gravity (log g) | 3.42±0.10 cgs |
| Temperature | 5,115±49 K |
| Metallicity [Fe/H] | −0.18±0.07 dex |
| Rotational velocity (v sin i) | 4.50 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
| ARICNS | A |
| B | |
χ Eridani (Latinised as Chi Eridani) is a binary star[10] system in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude of 3.70.[2] The distance to this system, as determined using the parallax method, is around 58 light years.[1] The pair had an angular separation of 5.0 arcseconds as of 1994. This corresponds to a projected separation of around 128 AU.[3]
The primary component is an evolving G-type subgiant star with a stellar classification of G8 IV.[4] It is about 1.6 times the mass of the Sun and has 4 times the Sun's radius.[8] The star shines with 10 times the solar luminosity from its outer atmosphere at an effective temperature of 5,115 K.[7] Unusually for a star of this class, it shows a photometric variability of 0.04 in magnitude, which may be due to a previous mass transfer from the secondary companion, or else from an undiscovered third companion.[8]
The companion is about 7 magnitudes fainter than the primary and may be the source of the X -ray emission from this system. This emission has a luminosity of 504.4×1027 erg s−1.[8]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data (SIMBAD), Bibcode: 1986EgUBV........0M.
- ↑ 3.0 3.1 3.2 Poveda, A. et al. (April 1994), "Statistical studies of visual double and multiple stars. II. A catalogue of nearby wide binary and multiple systems", Revista Mexicana de Astronomía y Astrofísica 28 (1): 43–89, Bibcode: 1994RMxAA..28...43P. See pp. 58–59.
- ↑ 4.0 4.1 Torres, C. A. O. et al. (December 2006), "Search for associations containing young stars (SACY). I. Sample and searching method", Astronomy and Astrophysics 460 (3): 695–708, doi:10.1051/0004-6361:20065602, Bibcode: 2006A&A...460..695T.
- ↑ Houk, N. (1978). Michigan catalogue of two-dimensional spectral types for the HD stars. 2. Dept. of Astronomy, University of Michigan. Bibcode: 1978mcts.book.....H.
- ↑ Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode: 2006AstL...32..759G.
- ↑ 7.0 7.1 Rains, Adam D. et al. (April 2020). "Precision angular diameters for 16 southern stars with VLTI/PIONIER". Monthly Notices of the Royal Astronomical Society 493 (2): 2377–2394. doi:10.1093/mnras/staa282. Bibcode: 2020MNRAS.493.2377R.
- ↑ 8.0 8.1 8.2 8.3 Fuhrmann, K.; Chini, R. (2012), "Multiplicity among F-type Stars", The Astrophysical Journal Supplement 203 (2): 20, doi:10.1088/0067-0049/203/2/30, 30, Bibcode: 2012ApJS..203...30F.
- ↑ "* chi Eri -- Pre-main sequence Star". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+chi+Eri+--+Pre-main+sequence+Star.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
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