Anna Żytkow

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Anna N. Żytkow ( [ˈanːa ˈʐɨtkɔf] ; * February 21, 1947 ) is a Polish astrophysicist at the Institute of Astronomy at the University of Cambridge .

Żytkow and Kip Thorne proposed a model for an astronomical object of a star inside a star, a so-called Thorne-Żytkow object . In 2014, Żytkow worked in a team led by Emily M. Levesque , who discovered the first candidate for such an object.

Thorne Żytkow objects

Together with Kip Thorne , Żytkow developed a theoretical model for a new genus of stars in 1976, the Thorne-Żytkow object (TŻO), which has either a neutron star or a black hole as the core inside a stellar shell. Such a star only develops very rarely and only two processes are known by which a TŻO can develop in its structure. In the first process, the collision of a neutron star with a normal star (either dwarf or giant star) results in the connection of the two into one object. This process is rare because star collisions are rare even within dense star clusters. The second process can take place at the transition of a star to a red supergiant, in the course of which a neutron star forms in the core that does not shed its star shell. The research group under Emily Levesque ( University of Colorado at Boulder ) discovered the first promising candidate in 2014 for a TŻO with the 6.5 m Magellan Clay Telescope at the Las Campanas Observatory after a good 40 years of searching for this exotic genus of stars.

Discoveries in the Kuiper Belt

Minor planets discovered : 7 
(8012) 1990 HO April 29, 1990
(8361) 1990 JN May 1, 1990
(15810) Arawn May 12, 1994
(16684) 1994 JQ May 11, 1994
(48443) 1990 HY April 29, 1990
(58165) 1990 HQ April 29, 1990
(73682) 1990 HU April 29, 1990
discovered with Mike Irwin

In December 1995, Mike Irwin , Scott Tremaine and Anna Żytkow found two slow objects as part of a survey of a section of the sky, which are considered candidates for objects in the Kuiper Belt .

Żytkow et al. followed the work of Edgeworth (1949) and Kuipers (1951), who suspect that protoplanetary disks extend far beyond Neptune's orbit and that the material outside of Neptune's orbit has not yet been able to form into planets.

Fonts (selection)

  • with C. Clare Worley, Mike J. Irwin, Christopher A. Tout, Morgan Fraser, Robert G. Izzard: The proper motion of HV2112: A TŻO candidate in the SMC . In: Monthly Notices of the Royal Astronomical Society: Letters . tape 459 , no. 1 , June 11, 2016, p. L31-L35 , doi : 10.1093 / mnrasl / slw034 , arxiv : 1602.08479 .
  • with Emily M. Levesque, P. Massey, N. Morrell: A Search for Thorne-Żytkow Objects . tape 223 , January 2014, p. 113.06 , bibcode : 2014AAS ... 22311306L .
  • with Christopher A. Tout, Ross P. Church, Herbert HB Lau: HV2112, a Thorne-Żytkow Object or a Super Asymptotic Giant Branch Star . In: Monthly Notices of the Royal Astronomical Society: Letters . tape 445 , no. 1 , November 21, 2014, p. L36-L40 , doi : 10.1093 / mnrasl / slu131 , arxiv : 1406.6064 .
  • with Emily M. Levesque, Philip Massey, Nidia Morrell: Discovery of a Thorne-Żytkow object candidate in the Small Magellanic Cloud . In: Monthly Notices of the Royal Astronomical Society: Letters . tape 443 , no. 1 , September 2014, p. L94-L98 , doi : 10.1093 / mnrasl / slu080 , arxiv : 1406.0001 .
  • with Warrick H. Ball, Christopher A. Tout: Quasi-stars, giants and the Schönberg – Chandrasekhar limit . In: Monthly Notices of the Royal Astronomical Society . tape 421 , no. 3 , 2012, p. 2713–2721 , doi : 10.1111 / j.1365-2966.2012.20508.x , arxiv : 1201.5560 .
  • with Mike Irwin: FY Aquilae and the gamma-ray burst GB 790331 . In: The Astrophysical Journal Letters . tape 433 , October 1994, p. L81-L84 , doi : 10.1086 / 187553 , bibcode : 1994ApJ ... 433L..81I .
  • with Mike Irwin: A variable star in the vicinity of the soft gamma-ray repeater 1806 - 20 . In: Monthly Notices of the Royal Astronomical Society . tape 263 , July 1993, p. L1 – L5 , doi : 10.1093 / mnras / 263.1.L1 , bibcode : 1993MNRAS.263L ... 1I .
  • with RC Cannon, PP Eggleton, P. Podsiadlowski: The structure and evolution of Thorne-Żytkow objects . In: The Astrophysical Journal . tape 386 , February 1992, p. 206-214 , doi : 10.1086 / 171006 , bibcode : 1992ApJ ... 386..206C .
  • with Chris Eich, Mark E. Zimmermann, Kip S. Thorne: Giant and supergiant stars with degenerate neutron cores . In: The Astrophysical Journal . tape 346 , November 1989, pp. 277-283 , doi : 10.1086 / 168008 , bibcode : 1989ApJ ... 346..277E .
  • with KS Thorne, RA Flammang: Stationary spherical accretion into black holes. I - Equations of structure . In: Monthly Notices of the Royal Astronomical Society . tape 194 , February 1981, p. 475-484 , doi : 10.1093 / mnras / 194.2.475 , bibcode : 1981MNRAS.194..475T .
  • with B. Paczyński: Hydrogen shell flashes in a white dwarf with mass accretion . In: The Astrophysical Journal . tape 222 , June 1978, p. 604-611 , doi : 10.1086 / 156176 , bibcode : 1978ApJ ... 222..604P .
  • with KS Thorne: Stars with degenerate neutron cores. I - Structure of equilibrium models . In: The Astrophysical Journal . tape 212 , March 1977, p. 832-858 , doi : 10.1086 / 155109 , bibcode : 1977ApJ ... 212..832T .
  • with KS Thorne: The relativistic equations of stellar structure and evolution . In: The Astrophysical Journal . tape 212 , March 1977, p. 825-831 , doi : 10.1086 / 155108 , bibcode : 1977ApJ ... 212..825T .
  • with KS Thorne: Red giants and supergiants with degenerate neutron cores . In: The Astrophysical Journal Letters . tape 199 , July 1975, p. L19 – L24 , doi : 10.1086 / 181839 , bibcode : 1975ApJ ... 199L..19T .
  • Are there optical counterparts to gamma-ray bursts? In: The Astrophysical Journal . tape 359 , August 1, 1990, pp. 138–154 , doi : 10.1086 / 169043 , bibcode : 1990ApJ ... 359..138Z .

Web links

literature

  • Jonathan I. Katz: The Biggest Bangs: The Mystery of Gamma-ray Bursts, the Most Violent Explosions in the Universe . Oxford University Press, 2002, ISBN 0-19-803333-8 , pp. 79 ( archive.org [accessed February 2, 2002]).

Individual evidence

  1. ↑ Mark Zimmermann: Soft Outside CrunchyCenter . zhurnaly.com. May 1, 2000. Retrieved July 24, 2011.
  2. ↑ Dr Anna N Żytkow . University of Cambridge . Retrieved July 24, 2011.
  3. ↑ Kip S. Thorne, Anna N. Żytkow: Stars with degenerate neutron cores. I - Structure of equilibrium models . In: The Astrophysical Journal . 212, No. 1, March 15, 1977, pp. 832-858. bibcode : 1977ApJ ... 212..832T . doi : 10.1086 / 155109 .
  4. ↑ a b c R. Cannon, P. Eggleton, A. Żytkow, P. Podsiadlowski: The Structure and Evolution of Thorne-Żytkow Objects . In: Institute of Astronomy, Madingley Road, Cambridge, UK (Ed.): The Astrophysical Journal . 386, 1992, p. 206. bibcode : 1992ApJ ... 386..206C . doi : 10.1086 / 171006 .
  5. ↑ Emily Levesque, Philip Massey, Anna Żytkow, Nidia Morrell: Discovery of a Thorne-Żytkow object candidate in the Small Magellanic Cloud . In: Monthly Notices of the Royal Astronomical Society Letters . 1406, May 30, 2014, p. L94. arxiv : 1406.0001 . bibcode : 2014MNRAS.443L..94L . doi : 10.1093 / mnrasl / slu080 .
  6. ^ Minor Planet Discoverers (by number) . In: Minor Planet Center . May 23, 2016. Retrieved June 20, 2016.
  7. ^ Anna Żytkow, Mike Irwin, Scott Tremaine: A Search for Slow-Moving Objects and the Luminosity Function of the Kuiper Belt . In: Institute of Astronomy, Madingley Road, Cambridge, United Kingdom (Ed.): The Astronomical Journal . 110, 1995, p. 3082. bibcode : 1995AJ .... 110.3082I . doi : 10.1086 / 117749 .
personal data
SURNAME Żytkow, Anna
ALTERNATIVE NAMES Zytkow, Anna N.
BRIEF DESCRIPTION Polish astrophysicist
DATE OF BIRTH February 21, 1947