NICER observation list: Target ID 261101

Abstract

We propose observing CAL 83 and MR Vel, two supersoft X-ray binaries, one in the Large Magellanic Cloud and one in the Galaxy. We will measure possible spectral changes over a period of many years since the last X-ray observations, and periodic modulations with time scales of tens of seconds or tens of minutes. The high luminosity and the not-exceedingly-supersoft spectrum of these two targets makes them ideal candidates for NICER, both from the point of view of feasibility and scientific interest and return. We will monitor the evolution and the amplitude changes of a 67 s period of CAL 83, search for short periodicities in the light curve of MR Vel, and measure again other, longer periods, of 38 minutes and 1 hour respectively, observed several years ago in each the two sources.
Obsid RA DEC l b Start End Exposure Number of
Modules
Number of
Processing
Status of
Processing
Date of
Processing
Public
date
2611010101 85.894 -68.373 278.565 -31.305 58592.3467 58592.4222 1104.0 52 2 VALIDATED 58596.8 58786
2611010102 85.891 -68.372 278.563 -31.306 58619.7699 58619.7840 878.0 52 1 VALIDATED 58624.2 58813
2611010103 85.892 -68.370 278.561 -31.306 58620.8816 58620.9579 996.0 52 2 VALIDATED 58624.6 58814
2611010104 85.892 -68.370 278.561 -31.306 58621.0103 58621.8447 11057.0 52 3 VALIDATED 58625.6 58815
2611010105 85.892 -68.373 278.564 -31.306 58622.1046 58622.2470 2763.0 52 3 VALIDATED 58626.7 58816
2611010106 85.890 -68.370 278.561 -31.307 58624.9861 58625.7833 7632.0 52 2 VALIDATED 58631.8 58819