| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Eridanus |
| Right ascension | 01 55 57.45606 |
| Declination | −51° 36′ 31.9736″ |
| Apparent magnitude (V) | 3.70 / 10.7 |
| Characteristics | |
| Spectral type | G8IV or G8IIIb CNIV |
| U−B color index | +0.46 |
| B−V color index | +0.85 |
| Astrometry | |
| Radial velocity (Rv) | –6.30 km/s |
| Proper motion (μ) | RA: +682.281 mas/yr Dec.: −295.332 mas/yr |
| Parallax (π) | 57.3774 ± 0.3291 mas |
| Distance | 56.8 ± 0.3 ly (17.43 ± 0.10 pc) |
| Absolute magnitude (MV) | 2.39 / 9.4 |
| Details | |
| A | |
| Mass | 1.58 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 | −0.18±0.07 dex |
| Rotational velocity (v sin i) | 4.50 km/s |
| Other designations | |
| χ Eri, FK5 68, GJ 81, HD 11937, HIP 9007, HR 566, SAO 232573 | |
| Database references | |
| SIMBAD | data |
| ARICNS | A |
| B | |
χ Eridani (Latinised as Chi Eridani) is a binary star system in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude of 3.70. The distance to this system, as determined using the parallax method, is around 58 light years. The pair had an angular separation of 5.0 arcseconds as of 1994. This corresponds to a projected separation of around 128 AU.
The primary component is an evolving G-type subgiant star with a stellar classification of G8 IV. It is about 1.6 times the mass of the Sun and has 4 times the Sun's radius. The star shines with 10 times the solar luminosity from its outer atmosphere at an effective temperature of 5,115 K. 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.
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 504.4×10 erg s.
References
- ^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
- ^ 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.
- ^ 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, arXiv:astro-ph/0609258, Bibcode:2006A&A...460..695T, doi:10.1051/0004-6361:20065602, S2CID 16080025.
- Houk, N. (1978). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 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. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
- ^ 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. arXiv:2004.02343. Bibcode:2020MNRAS.493.2377R. doi:10.1093/mnras/staa282.
- ^ Fuhrmann, K.; Chini, R. (2012), "Multiplicity among F-type Stars", The Astrophysical Journal Supplement, 203 (2): 20, Bibcode:2012ApJS..203...30F, doi:10.1088/0067-0049/203/2/30, 30.
- "* chi Eri -- Pre-main sequence Star". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-10-27.
{{cite web}}: CS1 maint: postscript (link) - 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
