Chi Scorpii, Latinized from χ Scorpii, is a single[9] star in the zodiac constellation of Scorpius. It has an orange hue and can be faintly seen with the naked eye with an apparent visual magnitude of 5.24.[2][5] Based upon parallax measurements, this star is around 448 light years from the Sun.[1] The star is drifting closer with a radial velocity of −23.6 km/s.[6]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 16h 13m 50.906s[1] |
| Declination | −11° 50′ 15.89″[1] |
| Apparent magnitude (V) | 5.24[2] |
| Characteristics | |
| Evolutionary stage | horizontal branch(57%chance) or red giant branch(43%chance)[3] |
| Spectral type | K3 III[4] |
| U−B color index | +1.54[5] |
| B−V color index | +1.39[2] |
| Astrometry | |
| Radial velocity (Rv) | −23.61±0.1[6] km/s |
| Proper motion (μ) | RA: −4.991 mas/yr[1] Dec.: −9.931 mas/yr[1] |
| Parallax (π) | 7.2874 ± 0.0993 mas[1] |
| Distance | 448 ± 6 ly (137 ± 2 pc) |
| Absolute magnitude (MV) | −0.08[2] |
| Details[3] | |
| Mass | 1.22+0.13 −0.14 M☉ |
| Radius | 25.92+0.78 −0.74 R☉ |
| Luminosity | 179.62+11.10 −9.55 L☉ |
| Surface gravity (log g) | 1.66±0.05 cgs |
| Temperature | 4,157+11 −10 K |
| Metallicity [Fe/H] | −0.01±0.10 dex |
| Rotational velocity (v sin i) | 8[7] km/s |
| Age | 8.39±2.64 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an aging K-type giant star with a stellar classification of K3 III,[4] which means it has exhausted the supply of hydrogen at its core. There is a 57% chance that this evolved star is on the horizontal branch and a 43% chance it is still on the red-giant branch. If it is on the former, the star is estimated to have 1.09 times the mass of the Sun, nearly 27 times the solar radius and shines with 191 times the Sun's luminosity. It is around 8 billion years old.[3]
Planetary system
editOne superjovian planet orbiting Chi Scorpii was detected in 2020 on a mildly eccentric orbit utilizing a radial velocity method.[10][11]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥4.32+0.15 −0.12 MJ |
1.45±0.02 | 573.4±2.0 | 0.06+0.03 −0.02 |
— | — |
See also
editReferences
edit- ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c Reffert, Sabine; et al. (2015), "Precise radial velocities of giant stars. VII. Occurrence rate of giant extrasolar planets as a function of mass and metallicity", Astronomy & Astrophysics, 574: A116, arXiv:1412.4634, Bibcode:2015A&A...574A.116R, doi:10.1051/0004-6361/201322360, hdl:10722/215277, S2CID 59334290. Values are for the slightly higher probability horizontal branch model fit.
{{citation}}: CS1 maint: postscript (link) - ^ a b Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
- ^ a b Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
- ^ a b Nidever, David L.; et al. (August 2002), "Radial Velocities for 889 Late-Type Stars", The Astrophysical Journal Supplement Series, 141 (2): 503–522, arXiv:astro-ph/0112477, Bibcode:2002ApJS..141..503N, doi:10.1086/340570, S2CID 51814894.
- ^ Bernacca, P. L.; Perinotto, M. (1970), "A catalogue of stellar rotational velocities", Contributi Osservatorio Astronomico di Padova in Asiago, 239 (1), Bibcode:1970CoAsi.239....1B.
- ^ "chi Sco -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-09-24.
- ^ 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.
- ^ Pinto, Marcelo Tala; Reffert, Sabine; Quirrenbach, Andreas; Stock, Stephan; Trifonov, Trifon; Mitchell, David S. (2020). "Precise radial velocities of giant stars". Astronomy & Astrophysics. 644: A1. doi:10.1051/0004-6361/202038285. hdl:10150/622444.
- ^ Marcelo, Tala Pinto (December 2020). "Precise radial velocities of giant stars. XIV. Evidence of planetary companions around HD 25723, 17 Sco, 3 Cnc, and 44 UMa" (PDF). Astronomy & Astrophysics. 644 (A1): 13. Bibcode:2020A&A...644A...1T. doi:10.1051/0004-6361/202038285.
- ^ 17 Sco b on exoplanet.eu
External links
edit- Kaler, James B. (August 12, 2016), "Chi and Psi Scorpii", Stars, University of Illinois, retrieved 2016-09-25.