Special Notice #129: Request extended to observe High-Mass X-Ray Binaries (HMXBs) in support of radial velocity observations

HMXB campaign extended until further notice. It has been updated numerous times and covered in AAVSO Alert Notices 348, 354, and 377, and in AAVSO Special Notices #118, #129, #143, #213, and #220.

October 27, 2008

Dr. Gordon Sarty, University of Saskatchewan, Canada, has requested our continuing assistance (see AAVSO Alert Notices 348, 354, 377, Special Notice 118) 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 two HMXBs:

Desig.   Name         R.A.(2000)  Dec.(2000)   Mag  LPH no.  AUID
2157+49  V2175 Cyg    22:01:38.2  +50:10:04.6  8.8  127    000-BDC-509
2204+54  4U 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 October 29 to November 9. The objective is to obtain simultaneous color photometry and radial velocity measurements of these two 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 two stars throughout the night. Interested AAVSO observers should concentrate on one or the other star for a whole night while we are observing. Tim Crawford will be observing at DAO for the first part of the run and you may wish to coordinate your observations with him through the AAVSO chat line or by contacting him at tcarchcape@yahoo.com.

For more background information on the HMXB project, please see our JAAVSO preprint at http://www.aavso.org/publications/ejaavso/ej56.shtml

Charts may be downloaded at:

"As mentioned in the earlier Alert Notices, please follow the observing instructions given on the chart web page and on the charts and submit your results directly to the AAVSO International Database.

"Please direct any questions about this observing campaign to Dr. Gordon Sarty at gordon.sarty@usask.ca.

"Many thanks for your all of your past observations."


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