Binary system: Difference between revisions
Content deleted Content added
not necessary |
m →Classification: Typo fixing, replaced: disinguished → distinguished |
||
| (28 intermediate revisions by 18 users not shown) | |||
| Line 1: | Line 1: | ||
{{short description|Two astronomical bodies which orbit each other}} |
|||
{{hatnote group| |
|||
{{For|binary numbers|Binary number}} |
|||
{{other uses}} |
{{other uses}} |
||
}} |
|||
{{Refimprove|date=February 2015}} |
{{Refimprove|date=February 2015}} |
||
A '''binary system''' is a system of two [[astronomical bodies]] |
A '''binary system''' is a system of two [[astronomical bodies]] of the same kind that are comparable in size. Definitions vary, but typically require the [[barycenter|center of mass]] to be located outside of either object. (See [[Barycenter#Gallery|animated examples]].) |
||
The most common binary |
The most common kinds of binary system are [[binary star]]s and [[binary asteroid]]s, but [[brown dwarf]]s, [[planet]]s, [[neutron star]]s, [[black hole]]s and [[galaxies]] can also form binaries. |
||
A ''multiple system'' is |
A ''multiple system'' is similar but consists of three or more objects, for example [[trinary star]]s and [[trinary asteroid]]s. |
||
== Classification == |
== Classification == |
||
In a binary system, the brighter object is referred to as '''[[primary (astronomy)|primary]]''', and the other the '''secondary'''. |
In a binary system, the brighter or more massive object is referred to as '''[[primary (astronomy)|primary]]''', and the other the '''secondary'''. |
||
Binary stars are also classified based on orbit. '''Wide binaries''' are objects with orbits that keep them apart from one another. They evolve separately and have very little effect on each other. '''Close binaries''' are close to each other and are able to transfer mass from one another. They can also be classified based on how we observe them. '''Visual binaries''' are two stars separated enough that they can be distinguished through binoculars or a small telescope. |
|||
They can also be classified based on how we observe them. '''Visual binaries''' are two stars separated enough that they can be viewed through a telescope or binoculars. |
|||
'''Eclipsing binaries''' are where the objects' orbits are at an angle that when one passes in front of the other it causes an [[eclipse]], as seen from Earth. |
'''Eclipsing binaries''' are where the objects' orbits are at an angle that when one passes in front of the other it causes an [[eclipse]], as seen from Earth. |
||
| Line 19: | Line 21: | ||
'''Astrometric binaries''' are objects that seem to move around nothing as their companion object cannot be identified, it can only be inferred. The companion object may not be bright enough or may be hidden in the glare from the primary object. |
'''Astrometric binaries''' are objects that seem to move around nothing as their companion object cannot be identified, it can only be inferred. The companion object may not be bright enough or may be hidden in the glare from the primary object. |
||
A related classification though not a binary system is '''optical binary''', which refers to objects that are so close together in the sky that they appear to be a binary system, but are not. Such objects merely appear to be close together, but lie at different distances from the Solar System.<ref>{{cite web |url=http://www.space.com/22509-binary-stars.html |title=Binary Star Systems: Classification and Evolution |publisher=[[Space.com]]}}</ref><ref>{{cite book |publisher= [[Thüringer Landessternwarte Tautenburg]] |title=Analysis of Spectroscopic Binaries |first=Holger |last=Lehmann}}</ref> |
A related classification though not a binary system is '''optical binary''', which refers to objects that are so close together in the sky that they appear to be a binary system, but are not. Such objects merely appear to be close together, but lie at different distances from the Solar System.<ref>{{cite web |url=http://www.space.com/22509-binary-stars.html |title=Binary Star Systems: Classification and Evolution |date=17 January 2018 |publisher=[[Space.com]]}}</ref><ref>{{cite book |publisher= [[Thüringer Landessternwarte Tautenburg]] |title=Analysis of Spectroscopic Binaries |first=Holger |last=Lehmann}}</ref> |
||
== Binary companion (minor planets) == |
== Binary companion (minor planets) == |
||
[[File:Pluto- |
[[File:Pluto-Charon_system-new.gif|thumb|right|The dwarf planet [[Pluto]] and its moon [[Charon (moon)|Charon]] are often described as a binary system in the [[Solar System]], which orbit the [[Sun]].]] |
||
{{main|Binary asteroid}} |
{{main|Binary asteroid}} |
||
When binary minor planets are similar in size, they may be called "[[Binary asteroid|binary companions]]" instead of referring to the smaller body as a satellite.<ref name="IAU-list">{{cite web |date=2009-09-17 |title=Satellites and Companions of Minor Planets |publisher=IAU / [[Minor Planet Center]] |url=http://www.cbat.eps.harvard.edu/minorsats.html | |
When binary minor planets are similar in size, they may be called "[[Binary asteroid|binary companions]]" instead of referring to the smaller body as a satellite.<ref name="IAU-list">{{cite web |date=2009-09-17 |title=Satellites and Companions of Minor Planets |publisher=IAU / [[Minor Planet Center]] |url=http://www.cbat.eps.harvard.edu/minorsats.html |access-date=2011-01-08 |url-status=dead |archive-url=https://web.archive.org/web/20110121153650/http://www.cbat.eps.harvard.edu/minorsats.html |archive-date=2011-01-21 }}</ref> Good examples of true binary companions are the [[90 Antiope]] and the [[79360 Sila–Nunam]] systems. [[Pluto]] and its largest moon [[Charon (moon)|Charon]] are sometimes described as a binary system because the [[barycenter]] (center of mass) of the two objects is not inside either of them, but Charon is small enough compared to Pluto that it is usually classified as a moon.<ref>{{cite web |url=http://news.discovery.com/space/can-we-call-pluto-and-charon-a-binary-planet-yet-140808.htm |title=Can We Call Pluto and Charon a 'Binary Planet' Yet? |author=Ian O'Neill |website=Discovery News |date=8 August 2014 |access-date=15 July 2015}}</ref> [[90482 Orcus|Orcus]] and its moon [[Vanth_(moon)|Vanth]] also orbit around a barycenter not inside either of them. |
||
The Sun and Jupiter orbit a point outside of either, but are not considered a binary because they are different kinds of objects. |
|||
==In popular culture== |
|||
{{main|Binary stars in fiction}} |
|||
*In the Discovery program ''[[Alien Planet]]'', the planet [[Darwin IV]] orbits a binary system. |
|||
*In ''[[The Hitchhiker's Guide to the Galaxy (novel)|The Hitchhiker's Guide to the Galaxy]]'', the planet [[Places in The Hitchhiker's Guide to the Galaxy#Magrathea|Magrathea]] orbits a binary system |
|||
*In the ''[[Invader Zim]]'' episode "Planet Jackers", one of the aforementioned Jackers mentions a binary system. |
|||
*Binary sun systems are featured in the ''[[Mass Effect 2]]'' game, these systems are in the [[Milky Way]] as explorable areas. |
|||
*A binary sun system is featured in the short story by Dan Simmons, "Orphans of the Helix." |
|||
*The planet Tatooine from [[Star Wars]] features a binary sun system. |
|||
==See also== |
==See also== |
||
| Line 50: | Line 44: | ||
==External links== |
==External links== |
||
*[https://www.nasa.gov/home/hqnews/2012/dec/HQ_12-425_Wide_Binary_Stars.html NASA Astrobiology Institute Shows How Wide Binary Stars Form - NASA] |
*[https://www.nasa.gov/home/hqnews/2012/dec/HQ_12-425_Wide_Binary_Stars.html NASA Astrobiology Institute Shows How Wide Binary Stars Form - NASA] |
||
*[https://ogle.astrouw.edu.pl/atlas/eclipsing_binaries.html OGLE Atlas of Variable Star Light Curves - Eclipsing binaries] |
|||
==Bibliography== |
==Bibliography== |
||
| Line 55: | Line 50: | ||
[[Category:Celestial mechanics]] |
[[Category:Celestial mechanics]] |
||
[[Category:Binary |
[[Category:Binary systems| Binary system]] |
||
[[Category:Astronomical dynamical systems]] |
[[Category:Astronomical dynamical systems]] |
||
Latest revision as of 15:44, 26 October 2024
 | This article needs additional citations for verification. (February 2015) |
A binary system is a system of two astronomical bodies of the same kind that are comparable in size. Definitions vary, but typically require the center of mass to be located outside of either object. (See animated examples.)
The most common kinds of binary system are binary stars and binary asteroids, but brown dwarfs, planets, neutron stars, black holes and galaxies can also form binaries.
A multiple system is similar but consists of three or more objects, for example trinary stars and trinary asteroids.
Classification
[edit]In a binary system, the brighter or more massive object is referred to as primary, and the other the secondary.
Binary stars are also classified based on orbit. Wide binaries are objects with orbits that keep them apart from one another. They evolve separately and have very little effect on each other. Close binaries are close to each other and are able to transfer mass from one another. They can also be classified based on how we observe them. Visual binaries are two stars separated enough that they can be distinguished through binoculars or a small telescope.
Eclipsing binaries are where the objects' orbits are at an angle that when one passes in front of the other it causes an eclipse, as seen from Earth.
Astrometric binaries are objects that seem to move around nothing as their companion object cannot be identified, it can only be inferred. The companion object may not be bright enough or may be hidden in the glare from the primary object.
A related classification though not a binary system is optical binary, which refers to objects that are so close together in the sky that they appear to be a binary system, but are not. Such objects merely appear to be close together, but lie at different distances from the Solar System.[1][2]
Binary companion (minor planets)
[edit]
When binary minor planets are similar in size, they may be called "binary companions" instead of referring to the smaller body as a satellite.[3] Good examples of true binary companions are the 90 Antiope and the 79360 Sila–Nunam systems. Pluto and its largest moon Charon are sometimes described as a binary system because the barycenter (center of mass) of the two objects is not inside either of them, but Charon is small enough compared to Pluto that it is usually classified as a moon.[4] Orcus and its moon Vanth also orbit around a barycenter not inside either of them. The Sun and Jupiter orbit a point outside of either, but are not considered a binary because they are different kinds of objects.
See also
[edit]
- Binary asteroid
- Binary star
- Contact binary
- Contact binary (small Solar System body)
- Double planet
- Rotational Brownian motion
References
[edit]- ^ "Binary Star Systems: Classification and Evolution". Space.com. 17 January 2018.
- ^ Lehmann, Holger. Analysis of Spectroscopic Binaries. Thüringer Landessternwarte Tautenburg.
- ^ "Satellites and Companions of Minor Planets". IAU / Minor Planet Center. 2009-09-17. Archived from the original on 2011-01-21. Retrieved 2011-01-08.
- ^ Ian O'Neill (8 August 2014). "Can We Call Pluto and Charon a 'Binary Planet' Yet?". Discovery News. Retrieved 15 July 2015.
External links
[edit]- NASA Astrobiology Institute Shows How Wide Binary Stars Form - NASA
- OGLE Atlas of Variable Star Light Curves - Eclipsing binaries
Bibliography
[edit]- Astronomy: A Visual Guide by Mark A. Garlick