Xi Hydrae, Latinised from ξ Hydrae, is a solitary[9] star in the equatorial constellation of Hydra. It was also given the Flamsteed designation19 Crateris. This magnitude 3.54[2] star is situated 130 light-years from Earth and has a radius about 10 times that of the Sun. It is radiating 58 times as much luminosity as the Sun.[6]
Star in the constellation Hydra
Xi Hydrae
Observation data Epoch J2000.0Equinox J2000.0 (ICRS)
One possible non-radial oscillation mode of Xi Hydrae
Flamsteed gave Xi Hydrae the designation 19 Crateris. He included a number of stars now within the IAU boundaries of Hydra as part of a Hydra & Crater constellation overlapping parts of both modern constellations.[10]
The star Xi Hydrae is particularly interesting in the field of asteroseismology since it shows solar-like oscillations. Multiple frequency oscillations are found with periods between 2.0 and 5.5 hours.[11]
Xi Hydrae has left the main sequence, having exhausted the supply of hydrogen in its core. Its spectrum is that of a red giant. Modelling its physical properties against theoretical evolutionary tracks shows that it has just reached the foot of the red giant branch for a star with an initial mass around 3M☉. This puts its age at about 510myr.[12]
Thévenin, F.; Kervella, P.; Pichon, B.; Morel, P.; Di Folco, E.; Lebreton, Y. (2005). "VLTI/VINCI diameter constraints on the evolutionary status of δ Eri, ξ Hya, η Boo". Astronomy and Astrophysics. 436 (1): 253. arXiv:astro-ph/0501420. Bibcode:2005A&A...436..253T. doi:10.1051/0004-6361:20042075. S2CID118169489.
Другой контент может иметь иную лицензию. Перед использованием материалов сайта WikiSort.org внимательно изучите правила лицензирования конкретных элементов наполнения сайта.
2019-2025 WikiSort.org - проект по пересортировке и дополнению контента Википедии