HD 224693
HD 224693 is a star in the equatorial constellation of Cetus, and is positioned near the western constellation border with Aquarius. It can be viewed with a small telescope but is too faint to be seen with the naked eye, having an apparent visual magnitude of 8.23.[2] Based on parallax measurements, the object is located at a distance of approximately 306 light years from the Sun. It is drifting further away with a radial velocity of 1.5 km/s.[1]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cetus |
| Right ascension | 23h 59m 53.8316s[1] |
| Declination | −22° 25′ 41.2159″[1] |
| Apparent magnitude (V) | 8.23[2] |
| Characteristics | |
| Spectral type | G2V[3] or G2IV[4] |
| B−V color index | 0.639±0.015[2] |
| Variable type | constant[4] |
| Astrometry | |
| Radial velocity (Rv) | 1.49±0.14[1] km/s |
| Proper motion (μ) | RA: 147.125±0.100[1] mas/yr Dec.: 26.853±0.058[1] mas/yr |
| Parallax (π) | 10.6666 ± 0.0577[1] mas |
| Distance | 306 ± 2 ly (93.8 ± 0.5 pc) |
| Absolute magnitude (MV) | 3.29[2] |
| Details | |
| Mass | 1.29±0.09[5] M☉ |
| Radius | 1.82+0.05 −0.04[1] R☉ |
| Luminosity | 3.78±0.03[1] L☉ |
| Surface gravity (log g) | 4.18±0.06[5] cgs |
| Temperature | 5,971+55 −88[1] K |
| Metallicity [Fe/H] | 0.28±0.02[5] dex |
| Rotational velocity (v sin i) | 4.2[6] km/s |
| Age | 3.0[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Extrasolar Planets Encyclopaedia | data |
The star HD 224693 is named Axólotl. The name was selected in the NameExoWorlds campaign by Mexico, during the 100th anniversary of the IAU. Axólotl means water animal in the native Nahuatl language, which is an amphibious species from the basin of Mexico.[7][8]
This is an ordinary G-type main-sequence star with a stellar classification of G2V.[3] However, in 2006, Johnson and associates assigned it a class of G2 IV, suggesting it is instead an evolving subgiant star.[4] It is about three[6] billion years old and chromospherically quiet,[4] with a projected rotational velocity of 4.2 km/s.[6] The star is metal rich, showing a higher abundance of elements other than hydrogen and helium when compared to the Sun.[4] It has 1.3[5] times the mass of the Sun and 1.8 times the Sun's radius. The star is radiating 3.78 times the luminosity of the Sun from its photosphere at an effective temperature of 5,971 K.[1]
In 2006, an extrasolar planet was discovered orbiting HD 224693 by the Keck telescope using radial velocity measurements. A preliminary search for transits using photometric data from Fairborn Observatory was inconclusive because data around the predicted time of transit was too sparse to rule out possible transits.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥0.7±0.12 MJ | 0.191±0.014 | 26.6904±0.0019 | 0.104±0.017 | — | — |
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.
- 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.
- Houk, Nancy; Smith-Moore, M. (1978). Michigan catalogue of two-dimensional spectral types for the HD stars. 4. Ann Arbor: Dept. of Astronomy, University of Michigan. Bibcode:1988mcts.book.....H.
- Johnson, John Asher; et al. (2006). "The N2K Consortium. VI. Doppler Shifts without Templates and Three New Short-Period Planets". The Astrophysical Journal. 647 (1): 600–611. arXiv:astro-ph/0604348. Bibcode:2006ApJ...647..600J. doi:10.1086/505173. S2CID 12421834.
- Santos, N. C.; et al. (2013). "SWEET-Cat: A catalogue of parameters for Stars With ExoplanETs". Astronomy and Astrophysics. 556. A150. arXiv:1307.0354. Bibcode:2013A&A...556A.150S. doi:10.1051/0004-6361/201321286. S2CID 55237847.
- Delgado Mena, E.; et al. (April 2015), "Li abundances in F stars: planets, rotation, and Galactic evolution", Astronomy & Astrophysics, 576: 24, arXiv:1412.4618, Bibcode:2015A&A...576A..69D, doi:10.1051/0004-6361/201425433, S2CID 56051637, A69.
- "Approved names". NameExoworlds. Retrieved 2020-01-02.
- "International Astronomical Union | IAU". www.iau.org. Retrieved 2020-01-02.
- Ment, Kristo; et al. (2018). "Radial Velocities from the N2K Project: Six New Cold Gas Giant Planets Orbiting HD 55696, HD 98736, HD 148164, HD 203473, and HD 211810". The Astronomical Journal. 156 (5). 213. arXiv:1809.01228. Bibcode:2018AJ....156..213M. doi:10.3847/1538-3881/aae1f5. S2CID 119243619.
External links
- "Notes for star HD 224693". The Extrasolar Planets Encyclopaedia.
