TITLE:   GCN CIRCULAR
NUMBER:  21816
SUBJECT: LIGO/VIRGO G298048: Precise position of SSS17a based on HST and Gaia
DATE:    17/09/05 00:30:09 GMT
FROM:    Mansi M. Kasliwal at Caltech  <mansi@astro.caltech.edu>

S. M. Adams, M. M. Kasliwal, N. Blagorodnova (Caltech)

report on behalf of a larger GROWTH (Global Relay of Observatories Watching
Transients Happen) collaboration

We registered our HST F336W image (PI Kasliwal) with the Gaia astrometric
catalog to derive a more precise position of SSS17a (Coulter et al. LVC GCN
21529). We find a position of 13:09:48.071 -23:22:53.37 with astrometric
residuals of 0.05". This new position is consistent with the position of
the radio source reported in companion GCNs by Corsi et al. LVC GCN 21815
and Mooley et al. LVC GCN 21814.