INTEGRAL/JEM-X detection of fading emission from GT Mus

On November 15th 2015 the MAXI/GSC detected a big flare from the RS CVn star GT Mus with a flux of ~100 mCrab in the 2-20 keV energy band. (ATel #8285). During recent INTEGRAL observations of the Musca region performed between 17 Nov 16:08 and 18 Nov 00:05 (UTC) the source GT Mus was within the field of view of JEM-X instruments for a net exposure time of 16.2 ks.

It was detected at a flux level of 9.0 +/- 0.9 mCrab (3-10 keV) in the combined JEM-X1 and JEM-X2 mosaic. The 5-sigma upper limit in the 10-25 keV energy range is 1 mCrab. The source was not detected with IBIS/ISGRI and we estimate a 3 sigma upper limit of about 25 mCrab in the 18-40 keV energy range.

In addition, INTEGRAL observed the Musca region on Nov 12 2015 between 11:14 and 17:11 (UTC) and the source was not significantly detected by JEM-X. We derive a 5-sigma upper limit of 4 mCrab (3-10 keV) for a net exposure time of 13.5 ks, in the combined JEM-X1 and JEM-X2 mosaic.