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SS433 Microquasar in Aquila

A very unusual binary system. Spectra taken show short period changes.


Image: S.Broadbent, HAG 24" RC, Canon 5D, 18 x 2min, ISO 3200

 SS433 (aka: V1342 Aql, K16 ... and others) is the faint orange object in the centre of the image which is about 9 arcmin square.

In 1977 Case Western Reserve University astronomers Bruce Stephenson and Nick Sanduleak listed it as the 433rd object in their catalog of objects with emission lines in their spectra.

It is a microquasar eclipsing binary system consisting of a large, hot, massive star and a stellar sized black hole. It lies in supernova remnant Westerhout 50 (W50, the Manatee nebula).

It varies in magnitude fron 12.5 to 15.2 (data from AAVSO)


Image: ESO - https://www.eso.org/public/images/eso9107b

The peaks in its spectrum vary with time in both intensity and position due to Doppler and relativistic effects caused by several processes:
  • The eclipsing binary period of 13.1 days
  • The black hole emits jets which precess with a period of 162.4 days
  • At irregular intervals, bright knots of material are ejected at relativistic speeds along the jets
Detailed spectra of the system taken with the HAG 24" RC telescope using a Lhires spectroscope can be seen here

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