TITLE: GCN CIRCULAR NUMBER: 30859 SUBJECT: GRB 210919a: Lowell Discovery Telescope upper limits DATE: 21/09/21 15:25:55 GMT FROM: Amy Gottlieb at UMD <Agottlieb7@gmail.com> <html xmlns:o=3D"urn:schemas-microsoft-com:office:office" xmlns:w=3D"urn:sc= hemas-microsoft-com:office:word" xmlns:m=3D"http://schemas.microsoft.com/of= fice/2004/12/omml" xmlns=3D"http://www.w3.org/TR/REC-html40"><head><meta ht= tp-equiv=3DContent-Type content=3D"text/html; charset=3Dutf-8"><meta name= =3DGenerator content=3D"Microsoft Word 15 (filtered medium)"><style><!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {margin:0in; font-size:11.0pt; font-family:"Calibri",sans-serif;} .MsoChpDefault {mso-style-type:export-only;} @page WordSection1 {size:8.5in 11.0in; margin:1.0in 1.0in 1.0in 1.0in;} div.WordSection1 {page:WordSection1;} --></style></head><body lang=3DEN-US style=3D'word-wrap:break-word'><div cl= ass=3DWordSection1><p class=3DMsoNormal>A.Gottlieb (UMD, NASA-GSFC), S.Dich= iara (UMD, NASA-GSFC), S.B. Cenko<o:p></o:p></p><p class=3DMsoNormal>= (NASA-GSFC), E. Troja (UMD, NASA-GSFC), J.M. Durbak (UMD), A. Kutyrev <o:p>= </o:p></p><p class=3DMsoNormal>(UMD, NASA-GSFC), S. Veilleux (UMD), report = on behalf of a larger <o:p></o:p></p><p class=3DMsoNormal>collaboration:<o:= p></o:p></p><p class=3DMsoNormal> <o:p></o:p></p><p class=3DMsoNormal>= We observed the field of the short GRB 210919A (Tohuvavohu et al., <o:p></o= :p></p><p class=3DMsoNormal>GCN Circ. 30846) using the Large Monolithic Ima= ger (LMI) on the 4.3m <o:p></o:p></p><p class=3DMsoNormal>Lowell Discovery = Telescope (LDT) at Happy Jack, AZ. Observations <o:p></o:p></p><p class=3DM= soNormal>started on September 21, 11:27:43 UT (2.46 days after the Swift <o= :p></o:p></p><p class=3DMsoNormal>trigger) taking 5 exposures of 200 s each= with SDSS r filter. <o:p></o:p></p><p class=3DMsoNormal>Observations were = taken at an airmass of about 1.27 and seeing of <o:p></o:p></p><p class=3DM= soNormal>about 1.5". We do not find any source inside the enhanced <o:= p></o:p></p><p class=3DMsoNormal>XRT position (Goad et al., GCN Circ. 30850= ) down to a 3-sigma <o:p></o:p></p><p class=3DMsoNormal>limiting magnitude = of r>23.6 AB mag.<o:p></o:p></p><p class=3DMsoNormal>Magnitudes are cali= brated against the SDSS catalog and not <o:p></o:p></p><p class=3DMsoNormal=
corrected for Galactic extinction.<o:p></o:p></p><p class=3DMsoNormal>&nbs= p;<o:p></o:p></p><p class=3DMsoNormal>We thank the staff of the Lowell Disc= overy Telescope for assistance <o:p></o:p></p><p class=3DMsoNormal>with the= se observations.<o:p></o:p></p><p class=3DMsoNormal> <o:p></o:p></p><p= class=3DMsoNormal><o:p> </o:p></p></div></body></html>