We present simultaneous high time resolution (1-10 Hz) X-ray and optical observations of the persistent LMXBs Sco X-1 and V801 Ara( = 4U 1636-536). In the case...

The accreting millisecond X-ray pulsar SAX J1808.4-3658 recently exhibited another outburst in September and October 2008 (ATel #1728). During this outburst, on...

Following the refined position of the faint X-ray transient XTE J1728-295 (ATel #2824) also named IGR J17285-2922 and currently in outburst (ATel #2823, #2825)...

We report the discovery of a previously unseen X-ray source detected in a 5ks Chandra/ACIS observation starting on 2008-11-27.72 UT as part of our ongoing...

We report the discovery of a previously unseen X-ray source detected in a 5ks Chandra/ACIS observation starting on 2009-03-11.59 UT as part of our ongoing...

Based on a 5ks Chandra ACIS-I observation of M31 on Nov 11 2009, we report a dramatic brightening of CXOM31 J004321.1+411751, [aka r3-7 (Kong et al. 2002 ApJ...

We report the discovery of 2 previously unseen X-ray sources detected in a 5ks Chandra/ACIS observation starting on 2008-09-01.32 UT as part of our ongoing...

We report on 3 Chandra ACIS-I observations containing the two M31 transient X-ray sources announced by Haberl et al. (2006, ATel #881) and followed up by...

As part of our ongoing Chandra/HST M31 transient program we report on a Chandra ACIS observation of M31 containing the new transient source reported by Pietsch...