TITLE: GCN CIRCULAR NUMBER: 22414 SUBJECT: GRB 180205A: SEDM Observations DATE: 18/02/13 15:30:27 GMT FROM: Virginia Cunningham at U of MD V. Cunningham (U of Maryland), J. D. Neill (Caltech), S. B. Cenko (NASA GSFC), and R. Walters (Caltech) report on behalf of the SEDM team: We observed the optical counterpart to GRB 180205A (Evans et al., GCN 22381) with the Spectral Energy Distribution Machine (SEDM) on the 60 inch telescope at Palomar Observatory. The SEDM is a low resolution (R ~ 100) integral field unit spectrometer with a multi-band (ugri) “rainbow” camera imager (see Blagorodnova et al., 2017, astro-ph/1710.02917). The SEDM began observing the optical counterpart at 04:44 UTC (18 minutes after the burst trigger time). We performed 2 x 1350 s exposures over the wavelength range 3800-10600 A. We see no strong evidence for emission or absorption features at the quoted redshift of z=1.409 (Tanvir et al., GCN 22384). The continuum emission is well-fit by a power law spectrum with index alpha = 0.77 (f_nu ~ nu^-alpha). [GCN OPS NOTE(07sep19): Per author's request, in the last sentence the "alpha = 0.67" was changed to "alpha = 0.77".]