Observatoire Solaire
  • Home
    • About us and contacts
    • Links
  • Books
    • Limousin Impact
    • Francois Felix Tisserand
    • Asteroids of Solar System
    • Solar Physics
    • Reviews
    • Downloadable Resources
  • Ice and Climate change
  • An astronomer's view of god
  • A brief guide to the Sun
  • News & Research
    • Asteroids & Limousin Impact >
      • Limousin impact gallery >
        • Rochechouart suevite & melts
        • Montoume suevite and schist
        • Valette impact melt & breccia
        • La Judie large flake mica schist
        • Chassenon lithic breccia
        • Champagnac environs
    • Stellar & Solar Physics
    • History of Astronomy >
      • Cluny musee
      • L'Observatoire de Meudon
      • L'astronome Jean Tarde
      • L'Observatoire de Toulouse
    • Astronomy Blog
    • History Blog
    • Blog Index
  • Asteroid Name Search

News updates : October 2019

10/18/2019

0 Comments

 
The discovery of Chiron
Regular readers of our monthly blog will be aware of the Centaurs. Today marks the discovery of the centaur Chiron, or to give it it’s complete designation 2060 Chiron (1977UB).  Aujourd’hui marque la découverte du centaure (2016)Chiron ou 2060 Chiron (1977UB).
 
Chiron a été découvert par l’astronome américaine Charles Kowal (8/11/1940 à 28/11/2011) à l’aide d’un télescope de 1,2m pendant qu’il travaillait à l’observatoire de Mont Palomar en Californie. L’iimportance de cette decouverte a été bientôt reconnue. Avant la découverte de Chiron, Hidalgo était considéré comme quelque chose d’exceptionnel. Mais les similarités entre l’Hidalgo et Chiron a permis l’identification d’une nouvelle classe d’objets – les Centaures.

 
It was discovered by Charles Kowal using a 1.2M telescope from the Mount Palomar observatory in California. The importance of the discovery was soon recognised.  Whereas prior to Chiron’s detection the anomalous object Hidalgo (944 Hidalgo (1920UB) was considered as a one-off, the close orbital similarities Chiron showed brought the identification of a new class of objects, the Centaurs.

Chiron is a fascinating object. With an aphelion distance (furthest distance from the Sun) of almost 19 AU (nearly as far as the planet Uranus) it was at the time of its discovery the most remote asteroidal object detected.
It is relatively large for an asteroid and has a diameter of 166km.  This has been determined by ‘stellar occultation’. An occultation is where the object being studied passes in front of a more remote object (such as a star) and eclipses the light from the remote object.

As we discussed during our Sept 2019 blog, Centaurs appear to orbit, spectroscopic, and features-wise be closer in nature to short period comets rather than asteroids. However, distinct differences from both major classes (comets and asteroids) are seen in the Centaurs.  For example the size of Chiron is quite exceptional for a comet; and thus they are considered to be transition, or hybrid objects between comets and asteroids. 

There has been some speculation recently that observations (Ruprecht, MIT, 2011), again using occultation, suggest that the Chiron has a ring structure – a bit like a much sparser version of the rings of the planet Saturn.  Our own view is that this explanation of the observations is very unlikely.  The size, and thus mass, of Chiron is insufficient to sustain a ring structure.

Our interpretation of the MIT observations is that the object exhibited a gaseous/dust outgassing (i.e. like the coma – the sublimation – of a comet). 
Picture
The Education of Achilles by Bénigne Gagneraux (1785) 
(Achilles riding on the back of Chiron)
0 Comments

    News Archives

    August 2020
    July 2020
    June 2020
    December 2019
    November 2019
    October 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    April 2018

    RSS Feed

Powered by Create your own unique website with customizable templates.