Jump to content

Draft:Stellar encounter

From Wikipedia, the free encyclopedia




A Stellar encounter is an astronomical event in which two or more stars get within a close distance of each other.[1] Encounters between stars outside dense regions are rare, but they are more frequent in regions dense with stars such as star clusters or multiple star systems. Impacts between two stars do happen but are extremely rare events.[2] Such stellar encounters can caused both star systems to exchange materials such as cosmic dust and planets. After such encounters, especially for stars with protoplanetary disk, both systems will come out with material from the other system.[3]

Scholz's Star (red star in the center) with VPHAS+ Image Credit: ESO VPHAS+
Scholz’s star (red center dot) passed within 55,000 light years of Earth around 70,000 years ago.[4]

Stars with protoplanetary disk in stellar rich regions undergo background heating, disk truncation and photoevaporation. Theses effects can halt the growth of gas giant planets during their planetary formation phase or not form any gas giant planets at all.[5]

A star with a protoplanetary disk near a massive hot star. The disk is being photoevaporated due to the heat from the large star.

Effects on the Solar system

[edit]

Stars that passes close to our Sun within 1-2 parsecs can have major effect a on the Solar system. Their gravity can perturb objects in the Oort Cloud sending comets from the outer solar system into the inner solar system in a “comet shower”,[6] some of which may collide with planet Earth.[7][1]

Stellar encounters to hot stars can expose the earth to powerful UV radiation. Nearby supernova can be devastating to life on Earth causing the total extinction of life on this planet and erode the ozone layer.[7]

Especially close stellar encounters can affect the orbits of the planets. A close star can disturb the orbits of the outer gas giant planets (Jupiter, Saturn, Uranus and Neptune). Their altered orbits can then affect the orbit of the other giant planets and the terrestrial planets including Earth. Such orbital alterations to the orbit of Earth can have major climate effects and caused major extinction events.[8]




References

[edit]
  1. ^ a b "Close encounters of the stellar kind". www.esa.int. Retrieved 2025-04-10.
  2. ^ "stellar encounter". astro.vaporia.com. Retrieved 2025-04-10.
  3. ^ "Stellar Flybys and Captured Planets". web.physics.utah.edu. Archived from the original on 2022-10-04. Retrieved 2025-04-10.
  4. ^ "A passing star: our Sun's near miss - NASA Science". 2019-02-26. Retrieved 2025-04-10.
  5. ^ Ndugu, N.; Abedigamba, O. P.; Andama, G. (May 2022). "Planet population synthesis: the role of stellar encounters". Monthly Notices of the Royal Astronomical Society. 512 (1): 861–873. doi:10.1093/mnras/stac569. ISSN 0035-8711. PMC 8924961. PMID 35308091.
  6. ^ Bobylev, Vadim V.; Bajkova, Anisa T. (2021-04-21), "Study of Close Stellar Encounters with the Solar System Based on Data from the Gaia EDR3 Catalogue", Astronomy Letters, 47 (3): 180–187, arXiv:2104.10487, Bibcode:2021AstL...47..180B, doi:10.1134/S1063773721020031, retrieved 2025-04-10
  7. ^ a b Bailer-Jones, C. a. L. (2015-03-01). "Close encounters of the stellar kind". Astronomy & Astrophysics. 575: A35. arXiv:1412.3648. Bibcode:2015A&A...575A..35B. doi:10.1051/0004-6361/201425221. ISSN 0004-6361.
  8. ^ "Did other stars reshape Earth's orbit? Check out these amazing stellar encounters". HT Tech. 2024-02-19. Retrieved 2025-04-10.