TITLE:   GCN CIRCULAR
NUMBER:  18242
SUBJECT: ANTARES neutrino detection: ANU 2.3m and Kepler K2 Observations of the Swift x-ray source
DATE:    15/09/05 00:48:24 GMT
FROM:    Fang Yuan at ANU  <fang.yuan@anu.edu.au>

B. E. Tucker, K. Freeman, F. Yuan, C. Wolf, B. Schmidt, D. Bayliss, C. Onken (Australian National University)

We report on the spectroscopic observation of the star associated with the Swift x-ray detection by Doric et al. (ATel #7987) which is within the ANTARES neutrino error region using the Wide Field Spectrograph (WiFeS - Dopita et al., 2007, ApSS, 310, 255) on the ANU 2.3m telescope at Siding Spring Observatory, NSW Australia, using the B7000/I7000 gratings (3500-9800 A, 1 A resolution). The spectrum shows features of a late-type (K5 - K7) dwarf star - strong MgH along with moderately-weak Balmer emission (i.e. H-beta and H-gamma). Additionally, the star was observed using the Kepler extended mission (K2) in Field 2 for about 70 days. A quick reduction of the K2 light-curve shows periodicity on the scale of about 1.5 days, indicating possible binarity.