We present the catalog of InterPlanetary Network (IPN) localizations for 199 short-duration gamma-ray bursts (sGRBs) detected by the Konus-Wind (KW) experiment between 2011 January 1 and 2021 August 31, which extends the initial sample of IPN-localized KW sGRBs to 495 events. We present the most comprehensive IPN localization data on these events, including probability sky maps in Hierarchical Equal Area isoLatitude Pixelization format.

GEOLOGIC MAP. Erica R. Jawin1, T. J. McCoy1, K. J. Walsh2, H. C. Connolly Jr.3,4, R.-L. Ballouz4, A. J. Ryan4, M. Pajola5, O. S. Barnouin6, H. H. Kaplan7, V. E. Hamilton2, J. P. Emery8, D. N. DellaGiustina4, D. J. Scheeres9, M. G. Daly10, C. A. Bennett4, D. R. Golish4, M. Perry6, R. T. Daly6, E. B. Bierhaus11, M. C. Nolan4, H. L. Enos4, and D. S. Lauretta4, Smithsonian National Museum of Natural History, Washington, DC, USA (jawine@si.edu), 2Southwest Research Institute, Boulder, CO, USA, 3Department of Geology, Rowan University, Glassboro, NJ, USA, 4Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA, 5INAF-Astronomical Observatory of Padova, Padova, Italy, 6Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA, 7Goddard Space Flight Research Center, Greenbelt, MD, USA, 8Northern Arizona University, Flagstaff, AZ, USA, 9University of Colorado, Boulder, CO, USA, 10Centre for Research in Earth and Space Science, York University, Toronto, Canada, 11Lockheed Martin Space, Littleton, CO, USA.

Soft γ-ray repeaters exhibit bursting emission in hard X-rays and soft γ-rays. During the active phase, they emit random short (milliseconds to several seconds long), hard-X-ray bursts, with peak luminosities 1 of 10 36 to 10 43 erg per second. Occasionally, a giant flare with an energy of around 10 44 to 10 46 erg is emitted 2 . These phenomena are thought to arise from neutron stars with extremely high magnetic fields (10 14 to 10 15 gauss), called magnetars 1 , 3 , 4 . A portion of the second-long initial pulse of a giant flare in some respects mimics short γ-ray bursts 5 , 6 , which have recently been identified as resulting from the merger of two neutron stars accompanied by gravitational-wave emission 7 . Two γ-ray bursts, GRB 051103 and GRB 070201, have been associated with giant flares 2 , 8 – 11 . Here we report observations of the γ-ray burst GRB 200415A, which we localized to a 20-square-arcmin region of the starburst galaxy NGC 253, located about 3.5 million parsecs away. The burst had a sharp, millisecond-scale hard spectrum in the initial pulse, which was followed by steady fading and softening over 0.2 seconds. The energy released (roughly 1.3 × 10 46 erg) is similar to that of the superflare 5 , 12 , 13 from the Galactic soft γ-ray repeater SGR 1806−20 (roughly 2.3 × 10 46 erg). We argue that GRB 200415A is a giant flare from a magnetar in NGC 253.

The Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) mission is a NASA New Frontiers mission that launched in 2016 and rendezvoused with the near-Earth asteroid (101955) Bennu in late 2018. Upon arrival, the surface of Bennu was found to be much rockier than expected. The original Touch-and-Go (TAG) requirement for sample collection was to deliver the spacecraft to a site with a 25-meter radius; however, the largest hazard-free sites are no larger than 8 meters in radius. To accommodate the dearth of safe sample collection sites, the project re-evaluated all aspects of flight system performance pertaining to TAG in order to account for the demonstrated performance of the spacecraft and navigation prediction accuracies. Moreover, the project has baselined onboard natural feature tracking instead of lidar for providing the onboard navigation state update during the TAG sequence. This paper summarizes the improvements in error source estimation, enhancements in onboard trajectory correction, and results of recent Monte Carlo simulation to enable sample collection with the given constraints. TAG delivery and onboard navigation performance are presented for the final four candidate TAG sites.