TITLE: GCN CIRCULAR NUMBER: 43784 SUBJECT: SVOM alert sb26021801: LAST optical upper limit DATE: 26/02/19 13:17:44 GMT FROM: Ruslan Konno at Weizmann Institute of Science <ruslankonno@gmail.com> R. Konno (WIS), S. Garrappa (WIS), E. A. Zimmerman (WIS), A. Horowicz (WIS), E. O. Ofek (WIS), S. Ben-Ami (WIS), D. Polishook (WIS), O. Yaron (WIS), S. Fainer (WIS), A. Krassilchtchikov (WIS), Y. M. Shani (WIS), E. Segre (WIS), A. Gal-Yam (WIS), and S. Spitzer (WIS) report on behalf of the LAST Collaboration. We report observations of the X-ray transient alert sb26021801, reported by SVOM (Tan et al., GCN 43778). Observations were conducted with the Large Array Survey Telescope (LAST; Ofek et al. 2023, PASP 135, 5001; Ben-Ami et al. 2023, PASP 135, 5002). Observations of sb26021801 were taken over 11 sequential epochs in clear band (similar to the Gaia Bp band). The first epoch began at 2026-02-18 23:06:13 UTC (T-T0 = 0.76d). Each epoch consists of 20x20s exposures. We coadd a total of 160x20s exposure images and perform image subtraction using a reference image of the field. We do not detect any new optical source up to a limiting magnitude of 21.5 (AB) within the error region reported in Tan et al., GCN 43778. See also Fortin et al. GCN 43783 for further optical limits. LAST is a survey telescope array of the Weizmann Astrophysical Observatory (https://www.weizmann.ac.il/wao/). View this GCN Circular online at https://gcn.nasa.gov/circulars/43784. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...