TITLE:   GCN CIRCULAR
NUMBER:  21547
SUBJECT: LIGO/VIRGO G298048: Magellan Optical Spectrum of the Potential Optical Counterpart Associated with NGC 4993 
DATE:    17/08/18 05:46:33 GMT
FROM:    Ryan Foley at UCSC  <foley@ucsc.edu>

M. R. Drout, J. D. Simon, B. J. Shappee (Carnegie), K. Boutsia, J. Bravo, G. Prieto (Las Campanas Observatory), D. A. Coulter, R. J. Foley, C. D. Kilpatrick, M. R. Siebert (UCSC), and A. L. Piro (Carnegie) report

On 2017 Aug 18.02 UT, we obtained an optical spectrum of the transient source SSS17a (RA = 13:09:48.09 DECL. = -23:22:53.35, Coulter et al. 2017; GCN 21529) possibly associated with LIGO/Virgo G298048, with the LDSS-3 spectrograph on the 6.5m Magellan-Clay telescope at Las Campanas Observatory.  The resulting spectrum shows a blue and featureless continuum between 4000 and 10,000 Angstroms, consistent with a power-law.

Additional observations are encouraged.

[GCN OPS NOTE(18aug17):  Per author's request, the trigger ID
in the Subject-line was corected from 298045 to 298048.]