Special Notice #253: Request for Observations of MAXI J1836-194

September 10, 2011: Dr. Gregory Sivakoff (U. of Alberta) requests observations of the X-ray binary star MAXI J1836-194 as part of the JACPOT collaboration studying stellar radio jets from compact binaries.  There is no predetermined duration for this campaign, but observations are requested now to coincide with ongoing X-ray and radio observations.

According to ATel #3628 (Miller-Jones et al.), radio observations of the star indicate that it is probably a stellar black hole binary system.  Both radio and X-ray observations will continue, and the JACPOT team will also try to obtain further optical observations.  The AAVSO has been asked to provide optical photometry.  Both BVRcIc photometry and time-series observations are requested, but note that the object is faint: it is 16th magnitude at brightest and fainter than 20th magnitude at minimum.  A photometric comparison star sequence is available, but this object is not suited for visual observations.

MAXI J1836-194 is located at the following (J2000) coordinates:

        RA: 18 35 43.43 , Dec: -19 19 12.1

Charts for this object may be plotted using AAVSO VSP:


Please report all observations using the name "MAXI J1836-194".

This AAVSO Special Notice was prepared by M. Templeton.



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