HD 224693, also named Axólotl, 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 mas[1] |
| 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 |
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 and an axolotl is also a species of salamander endemic to the valley 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]
Planetary system
editIn 2006, an extrasolar planet was discovered orbiting HD 224693 by the Keck telescope using radial velocity measurements.[9] 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] This exoplanet was named Xolotl, after the Aztec god of fire and lightning.[10]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b / Xólotl | ≥0.7±0.12 MJ | 0.191±0.014 | 26.6904±0.0019 | 0.104±0.017 | — | — |
See also
editReferences
edit- ^ a b c d e f g h i j k 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.
- ^ 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 Houk, Nancy; Smith-Moore, M. (1978). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 4. Ann Arbor: Dept. of Astronomy, University of Michigan. Bibcode:1988mcts.book.....H.
- ^ a b c d e f 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.
- ^ a b c d 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.
- ^ a b c d 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". www.nameexoworlds.iau.org. Retrieved 2020-01-02.
- ^ "100 000s of People from 112 Countries Select Names for Exoplanet Systems In Celebration of IAU's 100th Anniversary". International Astronomical Union. December 17, 2019. Retrieved 2020-01-02.
- ^ "Exoplanet-catalog". Exoplanet Exploration: Planets Beyond our Solar System. Retrieved 2022-09-11.
- ^ Astronomy, Go. "Exoplanet Xolotl | Axolotl star | Cetus Constellation | GO ASTRONOMY". Go-Astronomy.com. Retrieved 2022-09-11.
- ^ 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
edit- "Notes for star HD 224693". Extrasolar Planets Encyclopaedia. Archived from the original on March 12, 2007.