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Stellar collision

August 25, 2023

A stellar collision is the coming together of two stars[1] caused by stellar dynamics within a star cluster, or by the orbital decay of a binary star due to stellar mass loss or gravitational radiation, or by other mechanisms not yet well understood.

Simulated collision of two neutron stars

Astronomers predict that events of this type occur in the globular clusters of our galaxy about once every 10,000 years.[2] On 2 September 2008 scientists first observed a stellar merger in Scorpius (named V1309 Scorpii), though it was not known to be the result of a stellar merger at the time.[3]

Any stars in the universe can collide, whether they are "alive", meaning fusion is still active in the star, or "dead", with fusion no longer taking place. White dwarf stars, neutron stars, black holes, main sequence stars, giant stars, and supergiants are very different in type, mass, temperature, and radius, and so react differently.[2]

A gravitational wave event that occurred on 25 August 2017, GW170817, was reported on 16 October 2017 to be associated with the merger of two neutron stars in a distant galaxy, the first such merger to be observed via gravitational radiation.[4][5][6][7]

Types of stellar collisions and mergers Edit

Type Ia supernovae Edit

Main article: Type Ia supernova

White dwarfs are the remnants of low-mass stars and, if they form a binary system with another star, they can cause large stellar explosions known as type Ia supernovae. The normal route by which this happens involves a white dwarf drawing material off a main sequence or red giant star to form an accretion disc. Much more rarely, a type Ia supernova occurs when two white dwarfs orbit each other closely.[8] Emission of gravitational waves causes the pair to spiral inward. When they finally merge, if their combined mass approaches or exceeds the Chandrasekhar limit, carbon fusion is ignited, raising the temperature. Since a white dwarf consists of degenerate matter, there is no safe equilibrium between thermal pressure and the weight of overlying layers of the star. Because of this, runaway fusion reactions rapidly heat up the interior of the combined star and spread, causing a supernova explosion.[8] In a matter of seconds, all of the white dwarf's mass is thrown into space.[9]

Neutron star mergers Edit

Main article: Neutron star merger

Neutron star mergers occur in a fashion similar to the rare type Ia supernovae resulting from merging white dwarfs. When two neutron stars orbit each other closely, they spiral inward as time passes due to gravitational radiation. When they meet, their merger leads to the formation of either a heavier neutron star or a black hole, depending on whether the mass of the remnant exceeds the Tolman–Oppenheimer–Volkoff limit. This creates a magnetic field that is trillions of times stronger than that of Earth, in a matter of one or two milliseconds. Astronomers believe that this type of event is what creates short gamma-ray bursts[10] and kilonovae.[11]

Thorne–Żytkow objects Edit

Main article: Thorne–Żytkow object

If a neutron star collides with red giant of sufficiently low mass and density, both can survive in the form of a peculiar hybrid known as Thorne–Żytkow object, with the neutron star surrounded by the red giant.

Binary star mergers Edit

About half of all the stars in the sky are part of binary systems, with two stars orbiting each other. Some binary stars orbit each other so closely that they share the same atmosphere, giving the system a peanut shape. While most contact binary stars are stable, a few have become unstable and have merged in the past for reasons not well understood (see relevant section below).

Formation of planets Edit

When two low-mass stars in a binary system merge, mass may be thrown off in the orbital plane of the merging stars, creating an excretion disk from which new planets can form.[12]

Discovery Edit

While the concept of stellar collision has been around for several generations of astronomers, only the development of new technology has made it possible for it to be more objectively studied. For example, in 1764, a cluster of stars known as Messier 30 was discovered by astronomer Charles Messier. In the twentieth century, astronomers concluded that the cluster was approximately 13 billion years old.[13] The Hubble Space Telescope resolved the individual stars of Messier 30. With this new technology, astronomers discovered that some stars, known as "blue stragglers", appeared younger than other stars in the cluster.[13] Astronomers then hypothesized that stars may have "collided", or "merged", giving them more fuel so they continued fusion while fellow stars around them started going out.[13]

Stellar collisions and the Solar System Edit

While stellar collisions may occur very frequently in certain parts of the galaxy, the likelihood of a collision involving the Sun is very small. A probability calculation predicts the rate of stellar collisions involving the Sun is 1 in 1028 years.[14] For comparison, the age of the universe is of the order 1010 years. The likelihood of close encounters with the Sun is also small. The rate is estimated by the formula:

N ~ 4.2 · D2 Myr−1

where N is the number of encounters per million years that come within a radius D of the Sun in parsecs.[15] For comparison, the mean radius of the Earth's orbit, 1 AU, is 4.82 × 10−6 parsecs.

Our star will likely not be directly affected by such an event because there are no stellar clusters close enough to cause such interactions.[14]

KIC 9832227 and binary star mergers Edit

KIC 9832227 is an example of an eclipsing contact binary star system. It is mainly composed of two stars orbiting each other so closely that they share the same atmosphere, giving the system a peanut shape. As the orbits of the two stars decay due to stellar mass loss and internal viscosity, the two stars will eventually merge, resulting in a luminous red nova.

An analysis of the eclipses of KIC 9832227 initially suggested that its orbital period was indeed shortening, and that the cores of the two stars would merge in 2022.[16][17][18][19] However subsequent reanalysis found that one of the datasets used in the initial prediction contained a 12-hour timing error, leading to a spurious apparent shortening of the stars' orbital period.[20][21][22][23]

The mechanism behind binary star mergers is not yet fully understood, and remains one of the main focuses of those researching KIC 9832227 and other contact binaries.

References Edit

  1. ^ Fred Lawrence Whipple (March 1939), "Supernovae and stellar collisions", Proceedings of the National Academy of Sciences of the United States of America, 25 (3): 118–25, Bibcode:1939PNAS...25..118W, doi:10.1073/pnas.25.3.118, PMC 1077725, PMID 16577876
  2. ^ a b Chang, Kenneth (13 June 2000), "Two Stars Collide; New Star is Born", The New York Times, retrieved 14 November 2010
  3. ^ Tylenda, R.; Hajduk, M.; Kamiński, T.; et al. (11 April 2011). "V1309 Scorpii: merger of a contact binary". Astronomy and Astrophysics. 528: A114. arXiv:1012.0163. Bibcode:2011A&A...528A.114T. doi:10.1051/0004-6361/201016221. S2CID 119234303.
  4. ^ Overbye, Dennis (16 October 2017), "LIGO Detects Fierce Collision of Neutron Stars for the First Time", The New York Times
  5. ^ Casttelvecchi, Davide (25 August 2017). "Rumours swell over new kind of gravitational-wave sighting". Nature. doi:10.1038/nature.2017.22482. Retrieved 27 August 2017.
  6. ^ Sokol, Josha (25 August 2017). "What Happens When Two Neutron Stars Collide?". Wired. Retrieved 27 August 2017.
  7. ^ Drake, Nadia (25 August 2017). "Strange Stars Caught Wrinkling Spacetime? Get the Facts". National Geographic. Retrieved 27 August 2017.
  8. ^ a b González Hernández, J. I.; Ruiz-Lapuente, P.; Tabernero, H. M.; Montes, D.; Canal, R.; Méndez, J.; Bedin, L. R. (26 September 2012). "No surviving evolved companions of the progenitor of SN 1006". Nature. 489 (7417): 533–536. arXiv:1210.1948. Bibcode:2012Natur.489..533G. doi:10.1038/nature11447. hdl:2445/127740. PMID 23018963. S2CID 4431391.
  9. ^ Freedman, Roger A., Robert M. Geller, William J. Kaufmann III(2009). The Universe 9th Edition,p.543-545. W.H. Freeman and Company, New York. ISBN 1-4292-3153-X
  10. ^ Rosswog, Stephan (2013). "Astrophysics: Radioactive glow as a smoking gun". Nature. 500 (7464): 535–6. Bibcode:2013Natur.500..535R. doi:10.1038/500535a. PMID 23985867.
  11. ^ Metzger, B. D.; Martínez-Pinedo, G.; Darbha, S.; Quataert, E.; et al. (August 2010). "Electromagnetic counterparts of compact object mergers powered by the radioactive decay of r-process nuclei". Monthly Notices of the Royal Astronomical Society. 406 (4): 2650. arXiv:1001.5029. Bibcode:2010MNRAS.406.2650M. doi:10.1111/j.1365-2966.2010.16864.x. S2CID 118863104.
  12. ^ Martin, E. L.; Spruit, H. C.; Tata, R. (2011). "A binary merger origin for inflated hot Jupiter planets". Astronomy & Astrophysics. 535: A50. arXiv:1102.3336. Bibcode:2011A&A...535A..50M. doi:10.1051/0004-6361/201116907. S2CID 118473108.
  13. ^ a b c "Stellar Collisions and vampirism give blue stragglers stars a 'cosmic facelift'", Asian News International, 29 December 2009
  14. ^ a b Lucentini, Jack (1 June 2000). . Space.com. Archived from the original on 19 April 2004. Retrieved 15 January 2014. By one calculation, the sun is likely to have one crash per 10,000 trillion, trillion years (that's 28 zeros), and it will burn out on its own accord much sooner than that.
  15. ^ Garcia-Sanchez, J.; et al. (24 August 1998), "Perturbation of the Oort Cloud by Close Stellar Approaches", Asteroid and Comet Dynamics, Tatrauska Lomnica, Slovak Republic, hdl:2014/19368{{citation}}: CS1 maint: location missing publisher (link)
  16. ^ Molnar, Lawrence A.; Noord, Daniel M. Van; Kinemuchi, Karen; Smolinski, Jason P.; Alexander, Cara E.; Cook, Evan M.; Jang, Byoungchan; Kobulnicky, Henry A.; Spedden, Christopher J. (2017). "Prediction of a Red Nova Outburst in KIC 9832227". The Astrophysical Journal. 840 (1): 1. arXiv:1704.05502. Bibcode:2017ApJ...840....1M. doi:10.3847/1538-4357/aa6ba7. ISSN 0004-637X. S2CID 118970956.
  17. ^ Kinemuchi, Karen (1 October 2013). "To Pulsate or to Eclipse? Status of KIC 9832227 Variable Star". arXiv:1310.0544 [astro-ph.SR].
  18. ^ Byrd, Deborah (6 January 2017). "Star predicted to explode in 2022". EarthSky. EarthSky Communications. Retrieved 6 January 2017.
  19. ^ "Colliding stars will light up the night sky in 2022". Science. 1 May 2017. Retrieved 7 January 2017.
  20. ^ Molnar, Lawrence A. (7 September 2018). "Supplementary material to Calvin College press release "Team of researchers challenge bold astronomical prediction", September 7, 2018". calvin.edu. Retrieved 8 September 2018.
  21. ^ Kucinski, Matt (7 September 2018). "Team of researchers challenge bold astronomical prediction". calvin.edu. Retrieved 8 September 2018.
  22. ^ Socia, Quentin J.; Welsh, William F.; Short, Donald R.; Orosz, Jerome A.; Angione, Ronald J.; Windmiller, Gur; Caldwell, Douglas A.; Batalha, Natalie M. (11 September 2018). "KIC 9832227: Using Vulcan Data to Negate the 2022 Red Nova Merger Prediction". Astrophysical Journal Letters. 864 (2): L32. arXiv:1809.02771. Bibcode:2018ApJ...864L..32S. doi:10.3847/2041-8213/aadc0d. S2CID 56134618.
  23. ^ Parks, Jake (7 September 2018). "Two stars will NOT merge and explode into red fury in 2022". astronomy.com.

External links Edit

  • "Pau Amaro Seoane MODEST working group 4 "Stellar Collisions"". Retrieved 20 May 2013.

August 25, 2023
stellar, collision, stellar, collision, coming, together, stars, caused, stellar, dynamics, within, star, cluster, orbital, decay, binary, star, stellar, mass, loss, gravitational, radiation, other, mechanisms, well, understood, source, source, source, source,. A stellar collision is the coming together of two stars 1 caused by stellar dynamics within a star cluster or by the orbital decay of a binary star due to stellar mass loss or gravitational radiation or by other mechanisms not yet well understood source source source source source source source source source source track track Simulated collision of two neutron starsAstronomers predict that events of this type occur in the globular clusters of our galaxy about once every 10 000 years 2 On 2 September 2008 scientists first observed a stellar merger in Scorpius named V1309 Scorpii though it was not known to be the result of a stellar merger at the time 3 Any stars in the universe can collide whether they are alive meaning fusion is still active in the star or dead with fusion no longer taking place White dwarf stars neutron stars black holes main sequence stars giant stars and supergiants are very different in type mass temperature and radius and so react differently 2 A gravitational wave event that occurred on 25 August 2017 GW170817 was reported on 16 October 2017 to be associated with the merger of two neutron stars in a distant galaxy the first such merger to be observed via gravitational radiation 4 5 6 7 Contents 1 Types of stellar collisions and mergers 1 1 Type Ia supernovae 1 2 Neutron star mergers 1 3 Thorne Zytkow objects 1 4 Binary star mergers 2 Formation of planets 3 Discovery 4 Stellar collisions and the Solar System 5 KIC 9832227 and binary star mergers 6 References 7 External linksTypes of stellar collisions and mergers EditType Ia supernovae Edit Main article Type Ia supernova White dwarfs are the remnants of low mass stars and if they form a binary system with another star they can cause large stellar explosions known as type Ia supernovae The normal route by which this happens involves a white dwarf drawing material off a main sequence or red giant star to form an accretion disc Much more rarely a type Ia supernova occurs when two white dwarfs orbit each other closely 8 Emission of gravitational waves causes the pair to spiral inward When they finally merge if their combined mass approaches or exceeds the Chandrasekhar limit carbon fusion is ignited raising the temperature Since a white dwarf consists of degenerate matter there is no safe equilibrium between thermal pressure and the weight of overlying layers of the star Because of this runaway fusion reactions rapidly heat up the interior of the combined star and spread causing a supernova explosion 8 In a matter of seconds all of the white dwarf s mass is thrown into space 9 Neutron star mergers Edit Main article Neutron star merger Neutron star mergers occur in a fashion similar to the rare type Ia supernovae resulting from merging white dwarfs When two neutron stars orbit each other closely they spiral inward as time passes due to gravitational radiation When they meet their merger leads to the formation of either a heavier neutron star or a black hole depending on whether the mass of the remnant exceeds the Tolman Oppenheimer Volkoff limit This creates a magnetic field that is trillions of times stronger than that of Earth in a matter of one or two milliseconds Astronomers believe that this type of event is what creates short gamma ray bursts 10 and kilonovae 11 Thorne Zytkow objects Edit Main article Thorne Zytkow object If a neutron star collides with red giant of sufficiently low mass and density both can survive in the form of a peculiar hybrid known as Thorne Zytkow object with the neutron star surrounded by the red giant Binary star mergers Edit About half of all the stars in the sky are part of binary systems with two stars orbiting each other Some binary stars orbit each other so closely that they share the same atmosphere giving the system a peanut shape While most contact binary stars are stable a few have become unstable and have merged in the past for reasons not well understood see relevant section below Formation of planets EditWhen two low mass stars in a binary system merge mass may be thrown off in the orbital plane of the merging stars creating an excretion disk from which new planets can form 12 Discovery EditWhile the concept of stellar collision has been around for several generations of astronomers only the development of new technology has made it possible for it to be more objectively studied For example in 1764 a cluster of stars known as Messier 30 was discovered by astronomer Charles Messier In the twentieth century astronomers concluded that the cluster was approximately 13 billion years old 13 The Hubble Space Telescope resolved the individual stars of Messier 30 With this new technology astronomers discovered that some stars known as blue stragglers appeared younger than other stars in the cluster 13 Astronomers then hypothesized that stars may have collided or merged giving them more fuel so they continued fusion while fellow stars around them started going out 13 Stellar collisions and the Solar System EditWhile stellar collisions may occur very frequently in certain parts of the galaxy the likelihood of a collision involving the Sun is very small A probability calculation predicts the rate of stellar collisions involving the Sun is 1 in 1028 years 14 For comparison the age of the universe is of the order 1010 years The likelihood of close encounters with the Sun is also small The rate is estimated by the formula N 4 2 D2 Myr 1where N is the number of encounters per million years that come within a radius D of the Sun in parsecs 15 For comparison the mean radius of the Earth s orbit 1 AU is 4 82 10 6 parsecs Our star will likely not be directly affected by such an event because there are no stellar clusters close enough to cause such interactions 14 KIC 9832227 and binary star mergers EditKIC 9832227 is an example of an eclipsing contact binary star system It is mainly composed of two stars orbiting each other so closely that they share the same atmosphere giving the system a peanut shape As the orbits of the two stars decay due to stellar mass loss and internal viscosity the two stars will eventually merge resulting in a luminous red nova An analysis of the eclipses of KIC 9832227 initially suggested that its orbital period was indeed shortening and that the cores of the two stars would merge in 2022 16 17 18 19 However subsequent reanalysis found that one of the datasets used in the initial prediction contained a 12 hour timing error leading to a spurious apparent shortening of the stars orbital period 20 21 22 23 The mechanism behind binary star mergers is not yet fully understood and remains one of the main focuses of those researching KIC 9832227 and other contact binaries References Edit Fred Lawrence Whipple March 1939 Supernovae and stellar collisions Proceedings of the National Academy of Sciences of the United States of America 25 3 118 25 Bibcode 1939PNAS 25 118W doi 10 1073 pnas 25 3 118 PMC 1077725 PMID 16577876 a b Chang Kenneth 13 June 2000 Two Stars Collide New Star is Born The New York Times retrieved 14 November 2010 Tylenda R Hajduk M Kaminski T et al 11 April 2011 V1309 Scorpii merger of a contact binary Astronomy and Astrophysics 528 A114 arXiv 1012 0163 Bibcode 2011A amp A 528A 114T doi 10 1051 0004 6361 201016221 S2CID 119234303 Overbye Dennis 16 October 2017 LIGO Detects Fierce Collision of Neutron Stars for the First Time The New York Times Casttelvecchi Davide 25 August 2017 Rumours swell over new kind of gravitational wave sighting Nature doi 10 1038 nature 2017 22482 Retrieved 27 August 2017 Sokol Josha 25 August 2017 What Happens When Two Neutron Stars Collide Wired Retrieved 27 August 2017 Drake Nadia 25 August 2017 Strange Stars Caught Wrinkling Spacetime Get the Facts National Geographic Retrieved 27 August 2017 a b Gonzalez Hernandez J I Ruiz Lapuente P Tabernero H M Montes D Canal R Mendez J Bedin L R 26 September 2012 No surviving evolved companions of the progenitor of SN 1006 Nature 489 7417 533 536 arXiv 1210 1948 Bibcode 2012Natur 489 533G doi 10 1038 nature11447 hdl 2445 127740 PMID 23018963 S2CID 4431391 Freedman Roger A Robert M Geller William J Kaufmann III 2009 The Universe 9th Edition p 543 545 W H Freeman and Company New York ISBN 1 4292 3153 X Rosswog Stephan 2013 Astrophysics Radioactive glow as a smoking gun Nature 500 7464 535 6 Bibcode 2013Natur 500 535R doi 10 1038 500535a PMID 23985867 Metzger B D Martinez Pinedo G Darbha S Quataert E et al August 2010 Electromagnetic counterparts of compact object mergers powered by the radioactive decay of r process nuclei Monthly Notices of the Royal Astronomical Society 406 4 2650 arXiv 1001 5029 Bibcode 2010MNRAS 406 2650M doi 10 1111 j 1365 2966 2010 16864 x S2CID 118863104 Martin E L Spruit H C Tata R 2011 A binary merger origin for inflated hot Jupiter planets Astronomy amp Astrophysics 535 A50 arXiv 1102 3336 Bibcode 2011A amp A 535A 50M doi 10 1051 0004 6361 201116907 S2CID 118473108 a b c Stellar Collisions and vampirism give blue stragglers stars a cosmic facelift Asian News International 29 December 2009 a b Lucentini Jack 1 June 2000 Researchers Claim First Proof That Stars Collide Space com Archived from the original on 19 April 2004 Retrieved 15 January 2014 By one calculation the sun is likely to have one crash per 10 000 trillion trillion years that s 28 zeros and it will burn out on its own accord much sooner than that Garcia Sanchez J et al 24 August 1998 Perturbation of the Oort Cloud by Close Stellar Approaches Asteroid and Comet Dynamics Tatrauska Lomnica Slovak Republic hdl 2014 19368 a href Template Citation html title Template Citation citation a CS1 maint location missing publisher link Molnar Lawrence A Noord Daniel M Van Kinemuchi Karen Smolinski Jason P Alexander Cara E Cook Evan M Jang Byoungchan Kobulnicky Henry A Spedden Christopher J 2017 Prediction of a Red Nova Outburst in KIC 9832227 The Astrophysical Journal 840 1 1 arXiv 1704 05502 Bibcode 2017ApJ 840 1M doi 10 3847 1538 4357 aa6ba7 ISSN 0004 637X S2CID 118970956 Kinemuchi Karen 1 October 2013 To Pulsate or to Eclipse Status of KIC 9832227 Variable Star arXiv 1310 0544 astro ph SR Byrd Deborah 6 January 2017 Star predicted to explode in 2022 EarthSky EarthSky Communications Retrieved 6 January 2017 Colliding stars will light up the night sky in 2022 Science 1 May 2017 Retrieved 7 January 2017 Molnar Lawrence A 7 September 2018 Supplementary material to Calvin College press release Team of researchers challenge bold astronomical prediction September 7 2018 calvin edu Retrieved 8 September 2018 Kucinski Matt 7 September 2018 Team of researchers challenge bold astronomical prediction calvin edu Retrieved 8 September 2018 Socia Quentin J Welsh William F Short Donald R Orosz Jerome A Angione Ronald J Windmiller Gur Caldwell Douglas A Batalha Natalie M 11 September 2018 KIC 9832227 Using Vulcan Data to Negate the 2022 Red Nova Merger Prediction Astrophysical Journal Letters 864 2 L32 arXiv 1809 02771 Bibcode 2018ApJ 864L 32S doi 10 3847 2041 8213 aadc0d S2CID 56134618 Parks Jake 7 September 2018 Two stars will NOT merge and explode into red fury in 2022 astronomy com External links Edit Pau Amaro Seoane MODEST working group 4 Stellar Collisions Retrieved 20 May 2013 Retrieved from https en wikipedia org w index php title Stellar collision amp oldid 1161031692, wikipedia, wiki, book, books, library,

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