GCN Circular 14590

David M. Smith (UC Santa Cruz), Andre Csillaghy (Fachhochschule Nordwestschweiz),
Kevin Hurley (UC Berkeley), Hugh Hudson (UC Berkeley, U. Glasgow), Steven Boggs
(UC Berkeley), and Andrew Inglis (NASA Goddard/CUA) report:

The Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI)
satellite observed the prompt emission of GRB 130427A (Maselli et
al. , GCN 14448
Not found
 
 
), with usable data over the approximate range 50 keV to
15 MeV, and a time resolution of 1us on each photon recorded.
Absolute timing accuracy is ~1ms.  Since the GRB was 122 degrees from
the Sun, the photons entered through the rear of the spectrometer.

The lightcurve of the main outburst in three energy bands is shown binned to 25ms 
resolution at:
http://scipp.ucsc.edu/~dsmith/rhessi/grb/130427a_longplot.gif
The black, red, and orange lightcurves represent the energy ranges 50 keV to 1 MeV,
1-5 MeV, and 5-15 MeV, respectively.  

The lightcurve of the slower, fainter peak of the GRB, about two minutes after
the primary outburst, is shown here:
http://scipp.ucsc.edu/~dsmith/rhessi/grb/130427a_lateplot.gif
The black, red, and orange lightcurves in this case represent the energy ranges 
50-200 keV, 200-500 keV, and 500 keV to 1 MeV, respectively.

RHESSI data are publicly available.  We invite anyone intending to use the RHESSI
data to consult with us about instrumental issues associated with the observation.