HaloSat Time Log

This table records the start and stop times of the uninterrupted observation intervals obtained by the three detectors on board of HaloSat and provides access to the HaloSat observations containing these intervals. HaloSat is the first astrophysics-focused CubeSat funded by NASA's Astrophysics Division (PI P. Kaaret, University of Iowa). HaloSat is designed to map soft X-ray oxygen line emissions across the sky in order to constrain the mass and spatial distribution of hot gas in the Milky Way. HaloSat was launched from the NASA Wallops Flight Facility and delivered to the International Space Station on May 21, 2018. HaloSat was deployed into orbit on July 13, 2018 and collected science data from October 15, 2018, until September 29, 2020. HaloSat reentered Earth's atmosphere on January 4, 2021. To trace the Galactic halo, HaloSat is equipped with a non-focusing instrument, comprised of three independent silicon drift detectors (SDD14, SDD38, SDD54) operating in the energy range of 0.4 - 7.0 keV with a field of view of 10 deg in diameter and an energy resolution of 84.8 +/- 2.7 eV at 677 eV and 137.4 +/- 0.9 eV at 5895 eV. The HaloSat data are divided by specific positions in the sky and labeled with a number, the sequence number. Each sequence number contains all data for a specific sky position collected during the HaloSat operations therefore each observation contains time intervals that may be apart day, week or months. This database table instead has in each record the start and stop times of one uninterrupted time interval of good data for a specific detector. This table therefore enables searches of the HaloSat data for a specific time event detected by different obsevatories. The contents of this database table are generated at the HEASARC using information from the data files. The table was created in April 2023. This is a service provided by NASA HEASARC.