| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Cassiopeia[1] |
| Krios | |
| Right ascension | 23h 51m 55.0287s[2] |
| Declination | +59° 42′ 48.601″[2] |
| Apparent magnitude (V) | 9.70[3] |
| Kronos | |
| Right ascension | 23h 52m 09.2434s[4] |
| Declination | +59° 42′ 26.521″[4] |
| Apparent magnitude (V) | 9.56[3] |
| Characteristics | |
| Krios | |
| Evolutionary stage | main sequence[5] |
| Spectral type | G0[5] |
| Kronos | |
| Evolutionary stage | main sequence[5] |
| Spectral type | G2[5] |
| Astrometry | |
| Krios | |
| Radial velocity (Rv) | −21.2[5] km/s |
| Proper motion (μ) | RA: +89.332[2] mas/yr Dec.: −29.319[2] mas/yr |
| Parallax (π) | 9.7559±0.0111 mas[2] |
| Distance | 334.3 ± 0.4 ly (102.5 ± 0.1 pc) |
| Kronos | |
| Radial velocity (Rv) | −20.13±0.18[4] km/s |
| Proper motion (μ) | RA: +88.949[4] mas/yr Dec.: −29.373[4] mas/yr |
| Parallax (π) | 9.7353±0.0109 mas[4] |
| Distance | 335.0 ± 0.4 ly (102.7 ± 0.1 pc) |
| Details | |
| Krios | |
| Mass | 1.06[6] M☉ |
| Radius | 1.09[6] R☉ |
| Luminosity | 1.28[6] L☉ |
| Surface gravity (log g) | 4.43±0.028[5] cgs |
| Temperature | 5,878±25[5] K |
| Metallicity [Fe/H] | 0.01±0.010[5] dex |
| Rotational velocity (v sin i) | 1.1[5] km/s |
| Age | 4.00+1.51 −1.56[5] Gyr |
| Kronos | |
| Mass | 1.04[6] M☉ |
| Radius | 1.16[6] R☉ |
| Luminosity | 1.36[6] L☉ |
| Surface gravity (log g) | 4.33±0.028[5] cgs |
| Temperature | 5,803±25[5] K |
| Metallicity [Fe/H] | 0.20±0.010[5] dex |
| Rotational velocity (v sin i) | 2.5[5] km/s |
| Age | 4.28+1.11 −1.03[5] Gyr |
| Other designations | |
| Krios: BD+58°2662, HD 240429, SAO 35851[7] | |
| Kronos: BD+58°2663, HD 240430, SAO 35854[8] | |
| Database references | |
| SIMBAD | HD 240429 |
| HD 240430 | |
Krios (designated HD 240429) and Kronos (HD 240430) are a wide binary star system in the constellation of Cassiopeia. Both components of the system are yellow G-type main-sequence stars.[5] Originally designated HD 240430 is a Sun-like star in appearance, but it seems to have eaten its own planets, for which it is given the nickname Kronos, after the Greek god and the leader of the first generation of Titans.[9] Its unusual properties were described by a team of astrophysicists at Princeton University in 2017, led by Semyeong Oh.[10]
The names Krios and Kronos both refer to the two Titans in Greek mythology, both of whom were part of the six sons and six daughters of Gaia and Uranus. They were first used for these stars in 2017[5] and were officially approved by the IAU Working Group on Star Names on 22 March 2026.[1]
Kronos and Krios are about 350 light years away from Earth.[11] Formed around four billion years ago, they originated from the same interstellar cloud. They are moving together through space and are assumed to orbit each other slowly, with an estimated period of about 10,000 years. Kronos has a higher abundance of elements such as lithium, magnesium and iron in its atmosphere than in that of Krios. They are the most chemically different binary stars to have been discovered to date. The unusual and rich chemical composition leads scientists to the conclusion that Kronos has destroyed many of its orbiting planets.[10] According to estimates, it might have absorbed at least 15 Earth masses.[5]
See also
References
- "IAU Catalog of Star Names". Retrieved 23 March 2026.
- 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.
- Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
- 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.
- Semyeong, Oh; Price-Whelan, Adrian M.; Brewer, John M.; Hogg, David W.; Spergel, David N.; Myles, Justin (2017). "Kronos and Krios: Evidence for Accretion of a Massive, Rocky Planetary System in a Comoving Pair of Solar-type Stars". The Astrophysical Journal. 854 (2): 138. arXiv:1709.05344. Bibcode:2018ApJ...854..138O. doi:10.3847/1538-4357/aaab4d. S2CID 119076217.
- Stassun, Keivan G.; et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467.
- "HD 240429". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 30 April 2018.
- "HD 240430". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 30 April 2018.
- Princeton University (12 October 2017). "Devourer of planets? Astronomers dub star 'Kronos': Sun-like star Kronos shows signs of having consumed 15 Earth masses worth of rocky planets, prompting astronomers to name it after the Titan who ate his children". ScienceDaily. Retrieved 15 October 2017.
- Sokol, Josh (21 September 2017). "Star nicknamed Kronos after eating its own planetary children". New Scientist. Retrieved 15 October 2017.
- Fuller-Wright, Liz (12 October 2017). "Devourer of planets? Princeton researchers dub star 'Kronos'". Princeton University. Retrieved 15 October 2017.
External links
- "Kronos: Devourer Of Worlds". PBS Space Time. January 31, 2018 – via YouTube.
- Miquelarena, P.; Saffe, C.; et al. (August 2024). "The largest metallicity difference in twin systems: High-precision abundance analysis of the benchmark pair Krios and Kronos". Astronomy & Astrophysics. 688: A73. arXiv:2406.06705. Bibcode:2024A&A...688A..73M. doi:10.1051/0004-6361/202449983.