HD 240429 and HD 240430
Observation data
Epoch J2000      Equinox J2000
Constellation Cassiopeia
HD 240429 (Krios)
Right ascension 23h 51m 55.0285s[1]
Declination +59° 42′ 48.613″[1]
Apparent magnitude (V) 9.70[2]
HD 240430 (Kronos)
Right ascension 23h 52m 09.2427s[1]
Declination +59° 42′ 26.526″[1]
Apparent magnitude (V) 9.56[2]
Characteristics
HD 240429
Spectral type G0[3]
HD 240430
Spectral type G2[3]
Astrometry
HD 240429
Radial velocity (Rv)−21.2[3] km/s
Proper motion (μ) RA: 89.25[4] mas/yr
Dec.: −29.68[4] mas/yr
Parallax (π)9.7004 ± 0.0250 mas[4]
Distance336.2 ± 0.9 ly
(103.1 ± 0.3 pc)
HD 240430
Radial velocity (Rv)−21.2[3] km/s
Proper motion (μ) RA: 89.41[4] mas/yr
Dec.: −30.12[4] mas/yr
Parallax (π)9.6884 ± 0.0257 mas[4]
Distance336.6 ± 0.9 ly
(103.2 ± 0.3 pc)
Details[3]
HD 240429
Surface gravity (log g)4.43 ± 0.028 cgs
Temperature5878 ± 25 K
Metallicity [Fe/H]0.01 ± 0.010 dex
Rotational velocity (v sin i)1.1 km/s
Age4.00+1.51
−1.56 Gyr
HD 240430
Surface gravity (log g)4.33 ± 0.028 cgs
Temperature5803 ± 25 K
Metallicity [Fe/H]0.20 ± 0.010 dex
Rotational velocity (v sin i)2.5 km/s
Age4.28+1.11
−1.03 Gyr
Other designations
HD 240429: BD+58° 2662, HD 240429, SAO 35851[5]
HD 240430: BD+58° 2663, HD 240430, SAO 35854[6]
Database references
SIMBADHD 240429
HD 240430

HD 240429 (nicknamed Krios) and HD 240430 (Kronos) is a wide binary star system in the constellation of Cassiopeia. Both components of the system are yellow G-type main-sequence stars.[3] 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.[7] Its unusual properties were described by a team of astrophysicists at Princeton University in 2017, led by Semyeong Oh.[8]

Kronos and Krios are about 350 light years away from Earth.[9] 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.[8] According to estimates, it might have absorbed at least 15 Earth masses.[3]

See also

References

  1. 1 2 3 4 Gaia Collaboration (2016). "Gaia Data Release 1". Astronomy & Astrophysics. 595: A2. arXiv:1609.04172. Bibcode:2016A&A...595A...2G. doi:10.1051/0004-6361/201629512. S2CID 1828208.
  2. 1 2 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.
  3. 1 2 3 4 5 6 7 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. doi:10.3847/1538-4357/aaab4d. S2CID 119076217.
  4. 1 2 3 4 5 6 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.
  5. ↑ "HD 240429". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 30 April 2018.
  6. ↑ "HD 240430". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 30 April 2018.
  7. ↑ 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.
  8. 1 2 Sokol, Josh (21 September 2017). "Star nicknamed Kronos after eating its own planetary children". New Scientist. Retrieved 15 October 2017.
  9. ↑ Fuller-Wright, Liz (12 October 2017). "Devourer of planets? Princeton researchers dub star 'Kronos'". Princeton University. Retrieved 15 October 2017.
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