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AAVSO Special Notice #197: Request for time-series photometry of U Sco AAVSO HOME > publications > special notice

AAVSO Special Notice #197

Request for time-series photometry of U Sco
March 2, 2010

Dr. Bradley Schaefer (LSU) requests intensive time-series observations
of U Scorpii beginning immediately and continuing through 2010 March 4
08:00 UT (JD 2455259.83).  These observations are requested in support
of coincident X-ray photometry by the XMM-Newton satellite.  The
XMM-Newton observations, requested by Dr. Jan-Uwe Ness (ESA), will
investigate the X-ray behavior of U Sco during its transition from
outburst back to quiescence.  These X-ray observations will likely
detect flickering, and coincident optical photometry will be important
to determine the physical causes of this variability and hence to better
understand U Sco and its outbursts.

The XMM observations will commence on 2010 March 3 14:16 UT (JD
2455259.09) and continue through 2010 March 4 08:01 UT (2455259.83). 
Observers are asked to obtain the best time-series observations possible
given the constraints of their observing system.  U Sco is currently
around V=15.5, and so getting good signal-to-noise is increasingly
challenging.  Please obtain the best signal to noise possible while
keeping integration times low, preferably under five (5) minutes, and
much less than 5 minutes if at all possible.  Unfiltered observations
are acceptable but please use a V filter if you have a larger telescope. 
The moon will be within 30 degrees so please be careful to avoid
contamination and saturation due to moonlight.

U Scorpii is located at the following (J2000) coordinates:

        RA: 16:22:30.78 , Dec: -17:52:42.8

Charts for U Sco may be plotted using AAVSO VSP:

Please report all observations to the AAVSO using the name "U SCO".

For more information on the U Sco outburst and its progress so far,
please visit the AAVSO's information page:

This AAVSO Special Notice was prepared by Matthew Templeton.


Information on submitting observations to the AAVSO may be found at:


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