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The Solar System Around a Binary Star

Nielsen, Jesper LU (2019) In Lund Observatory Examensarbeten ASTK02 20191
Lund Observatory
Abstract
The observations of circumbinary planets have confirmed that these can in fact be stable. While previous studies on circumbinary planets have been done, not many have been made on systems containing multiple circumbinary planets on eccentric orbits. In this thesis, the effects a binary star system of solar mass would have on the Solar System is investigated. Using the program MERCURY, numerous integrations of the Solar System around a tight binary with a separation of less than 1 AU are made and the stability of the orbits of Mercury, Venus, and Earth as a function of the binary separation and the binary mass ratio is investigated. An orbit is considered to be unstable if the planet gets ejected, collides with one of the stars or one of... (More)
The observations of circumbinary planets have confirmed that these can in fact be stable. While previous studies on circumbinary planets have been done, not many have been made on systems containing multiple circumbinary planets on eccentric orbits. In this thesis, the effects a binary star system of solar mass would have on the Solar System is investigated. Using the program MERCURY, numerous integrations of the Solar System around a tight binary with a separation of less than 1 AU are made and the stability of the orbits of Mercury, Venus, and Earth as a function of the binary separation and the binary mass ratio is investigated. An orbit is considered to be unstable if the planet gets ejected, collides with one of the stars or one of the other planets and the integrations last 10^5 years. The maximum eccentricity of Earth as a function of the binary separation is also investigated. What was found was that the orbit of Mercury was starting to become unstable at a binary separation of approximately $0.33-36a_{initial}$ depending on the mass ratio while Venus and Earth was starting to become unstable at a binary separation of approximately $0.41-0.44a_{initial}$ and $0.44-0.45a_{initial}$ respectively. Furthermore, it was found that there was an interval between $0.38-0.44a_{initial}$ where the maximum eccentricity of Earth were lower compared to binary separations between $0.3-0.37a_{initial}$ possibly due to resonance effects, meaning that Earth has a larger chance to stay within the habitability zone around a binary separation between $0.38-0.44a_{initial}$ (Less)
Popular Abstract (Swedish)
Vår stjärna solen är långt ifrån den enda i universum. Det finns enorma mängder stjärnor bara i vår egen galax. Man har upptäckt att en stor andel av av stjärnor existerar i binära par, det vill säga två stjärnor som kretsar kring varandra. Dessutom har nya observationer med hjälp av KEPLER teleskopet under 2010-talet har visat vad man endast har kunnat spekulera om i flera årtionden: planeter kan existera runt binära stjärnor.


En planets omloppsbana kan antingen vara en ellips eller en cirkel. Ett mått på hur avlång omloppsbanan är är dess eccentricitet. En omloppsbanas eccentricitet avgör hur avlång omloppsbanan är. En planet som kretsar kring en binär stjärna kan förändra sin eccentricitet genom att interagera med stjärnorna eller... (More)
Vår stjärna solen är långt ifrån den enda i universum. Det finns enorma mängder stjärnor bara i vår egen galax. Man har upptäckt att en stor andel av av stjärnor existerar i binära par, det vill säga två stjärnor som kretsar kring varandra. Dessutom har nya observationer med hjälp av KEPLER teleskopet under 2010-talet har visat vad man endast har kunnat spekulera om i flera årtionden: planeter kan existera runt binära stjärnor.


En planets omloppsbana kan antingen vara en ellips eller en cirkel. Ett mått på hur avlång omloppsbanan är är dess eccentricitet. En omloppsbanas eccentricitet avgör hur avlång omloppsbanan är. En planet som kretsar kring en binär stjärna kan förändra sin eccentricitet genom att interagera med stjärnorna eller andra planeter. Om avståndet mellan stjärnorna blir större och större får planeterna som kretsar runt dem större och större eccentricitet tills de slungas ut i rymden, bort från systemet. Det kan också innebära att Jorden hamnar utanför den beboeliga zonen, det vill säga det område runt solen där vatten kan existera i flytande form på ytan av en himlakropp.


En fråga man kan ställa sig är "hur vårt solsystem hade sett ut om vi hade kretsat kring en binär stjärna"? Genom att simulera vårt solsystem runt två stjärnor istället för en kan man se hur omloppsbanorna påverkas av avståndet mellan stjärnorna. Man kan då se hur stort avståndet mellan stjärnorna måste vara för att Merkurius, Venus och Jorden skulle skickas iväg från solsystemet. Man kan också undersöka hur stor skillnad det blir på eccentriciteten hos planeterna om man ökar avståndet mellan stjärnorna och om jorden faktiskt kan vara beboelig runt en binär stjärna. (Less)
Please use this url to cite or link to this publication:
author
Nielsen, Jesper LU
supervisor
organization
course
ASTK02 20191
year
type
M2 - Bachelor Degree
subject
keywords
planetary system stability, binary star
publication/series
Lund Observatory Examensarbeten
report number
2019-EXA152
language
English
id
8985332
date added to LUP
2019-08-06 09:02:08
date last changed
2019-08-06 09:02:08
@misc{8985332,
  abstract     = {The observations of circumbinary planets have confirmed that these can in fact be stable. While previous studies on circumbinary planets have been done, not many have been made on systems containing multiple circumbinary planets on eccentric orbits. In this thesis, the effects a binary star system of solar mass would have on the Solar System is investigated. Using the program MERCURY, numerous integrations of the Solar System around a tight binary with a separation of less than 1 AU are made and the stability of the orbits of Mercury, Venus, and Earth as a function of the binary separation and the binary mass ratio is investigated. An orbit is considered to be unstable if the planet gets ejected, collides with one of the stars or one of the other planets and the integrations last 10^5 years. The maximum eccentricity of Earth as a function of the binary separation is also investigated. What was found was that the orbit of Mercury was starting to become unstable at a binary separation of approximately $0.33-36a_{initial}$ depending on the mass ratio while Venus and Earth was starting to become unstable at a binary separation of approximately $0.41-0.44a_{initial}$ and $0.44-0.45a_{initial}$ respectively. Furthermore, it was found that there was an interval between $0.38-0.44a_{initial}$ where the maximum eccentricity of Earth were lower compared to binary separations between $0.3-0.37a_{initial}$ possibly due to resonance effects, meaning that Earth has a larger chance to stay within the habitability zone around a binary separation between $0.38-0.44a_{initial}$},
  author       = {Nielsen, Jesper},
  keyword      = {planetary system stability,binary star},
  language     = {eng},
  note         = {Student Paper},
  series       = {Lund Observatory Examensarbeten},
  title        = {The Solar System Around a Binary Star},
  year         = {2019},
}