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GCN Circular 27215

GRB 200224B: DDOTI/OAN optical observations report
2020-02-26T00:30:12Z (4 years ago)
Emma Margarita Pereyra Talamantes at IA-UNAM Ensenada <>
Margarita Pereyra (UNAM), Nat Butler (ASU), Alan M. Watson (UNAM),
Eleonora Troja (GSFC/UMD), Simone Dichiara (GSFC/UMD), Rosa L. Becerra
(UNAM), William H. Lee (UNAM), Diego Gonzalez (UNAM), Alexander Kutyrev
(GSFC/UMD), and Tanner Wolfram (ASU), report:

We observed the field of GRB 200224B detected by the Fermi Gamma-ray Burst
Monitor (GCN 27174, Fermi trigger 604213554), with the DDOTI/OAN wide-field
imager at the Observatorio Astron��mico Nacional on Sierra San Pedro M��rtir ( from 2020-02-24 06:47 to 2020-02-24 12:16
UTC (1.68 to 7.16 hours after the event).

We observed a region of 13.6 degrees in RA by 20.4 degrees in declination,
with a 2 x 2 grid, centered on the Fermi GBM Final Position +11:51:36
-28:52:11 J2000. This region contains about 277 square degrees. We obtained
2040 to 2520 seconds exposure across the region. We calibrated our images
against the APASS catalog. Our 10-sigma limiting magnitude is around w =

Comparing to the USNO-B1, DSS DR2 and Pan-STARRS DR1 catalogs, we do not
detect any uncataloged source with significant fading within the 90%
probability radius of 6.3 degrees.

We thank the staff of the Observatorio Astron��mico Nacional in San Pedro

*Dr. Margarita Pereyra *

*FFTF, Schlumberger Foundation Alumnae*

*Catedr��tico Conacyt*

*Instituto de Astronom��a de la UNAM,*

*Km. 107 Carretera Tijua**na-Ensenada, *

*Ensenada Baja California, M��xico. C.P. 22860*

Oficina: 405

Skype: margarita-pereyra
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