NICER / ISS Science Nugget for June 6, 2019

NICER teams up with OSIRIS-Rex for calibration study

On June 2, NICER conducted observations of the bright X-ray source Sco X-1 simultaneously with the REXIS instrument on OSIRIS-Rex. The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) is asteroid study and sample return mission currently in the vicinity of the asteroid Bennu. The Regolith X-ray Imaging Spectrometer (REXIS) on OSIRIS-Rex will provide an X-ray Spectroscopy map of Bennu to constrain the abundances of chemical elements on its surface, which fluoresce under Solar illumination. The absolute calibration of REXIS depends on a Silicon Drift Detector (SDD) that monitors the Sun's brightness in X-rays. This SDD is derived from the NICER detector system.

The objective of the June 2 coordinated NICER/OSIRIS-REx observations of Sco X-1 is to transfer NICER's X-ray flux calibration to the REXIS SDD and, in turn, to the REXIS instrument. The NICER data (see figure) were provided to the OSIRIS-REx/REXIS team, with support from the NICER science team.

In other planetary science news, NICER also conducted simultaneous observations of Jupiter this past week with the JUNO spacecraft near Jupiter. These observations were performed in conjunction with Hubble, Chandra, and DISCOVR.