Special Notice #159: Request for observations of high-mass X-ray binaries

AAVSO Special Notice #159

Request for observations of high-mass X-ray binaries
May 18, 2009

Dr. Gordon Sarty, University of Saskatchewan, Canada, has requested ourcontinuing assistance (see AAVSO Alert Notices 348, 354, 377, AAVSO Special Notices #118, #129, #143) in his ongoing radial velocity observations of High Mass X-ray Binaries (HMXBs). The following text was provided by Dr. Sarty:

"Please obtain BVRI photometry (or any subset thereof, VI preferred) of the following four HMXBs:

Desig.   Name            R.A.(2000) Dec.(2000)  Mag  LPH no.  AUID
1930+53 1936+541        19:32:52.3  +53:52:45.5  9.8  115    000-BDC-070 [1H 1936+541]
2027+47 J2030.5+47      20:30:30.9  +47:51:50.7  9.3  123    000-BDC-306 [RX J2030.5+4751]
2157+49 2202+501        22:01:38.2  +50:10:04.6  8.8  127    000-BFS-469 [V2175 Cyg]
2204+54 2206+543        22:07:57.1  +54:31:05.8  9.9  128    000-BDC-531 [V1008 Cep]

for the time period of our radial velocity observations from May 29 to June 11. The objective is to obtain simultaneous color photometry and radial velocity measurements of these four objects.

Our radial velocity measurements will be done with the Dominion Astrophysical Observatory (DAO) 1.85-m Plaskett telescope, in Victoria, B.C., Canada. We will alternate observations of the four stars throughout the night. The observer will be Neil Johnson, who can be reached on the AAVSO chat-line during the observations. Interested AAVSO observers should concentrate on one star per night, all night, for as many nights as you can devote, while we are observing.

For more background information on the HMXB project, please see our JAAVSO preprint at http://www.aavso.org/publications/ejaavso/v35n2/327.shtml

Charts may be downloaded at:

http://homepage.usask.ca/~ges125/Astronomy/LPH115_aavso.pdf
http://homepage.usask.ca/~ges125/Astronomy/LPH123_aavso.pdf
http://homepage.usask.ca/~ges125/Astronomy/LPH127_aavso.pdf
http://homepage.usask.ca/~ges125/Astronomy/LPH128_aavso.pdf

Please submit your observations directly to the AAVSO International Database.

Thanks for your ongoing coverage of the HMXBs.

Please direct any questions about this observing campaign to

Dr. Gordon Sarty at gordon.sarty@usask.ca ."

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