TITLE:   GCN CIRCULAR
NUMBER:  20757
SUBJECT: LIGO/Virgo G275404: Keck spectrum of MASTER OT J105958.00-115756.5
DATE:    17/02/26 19:08:17 GMT
FROM:    Igor Andreoni at Swinburne U of Tech  <igor.andreoni@gmail.com>

J. Cooke, I. Andreoni, U. Mestric (Swinburne Univ.), T. Moriya (NAOJ)

 

A spectrum of the MASTER transient OT J105958.00-115756.5 (GCN Circ. 20748) was taken with the Keck telescope on 2017-02-26.54 UT during the follow up of the LIGO event G275404 (LIGO/VIRGO Collaboration GCN Circ. 20738).

 

The observations were performed with the Low Resolution Imaging Spectrometer for a total exposure time of 2300s under several magnitudes of variable cloud extinction.



The preliminary analysis reveals a blue and mostly featureless spectrum at redshift z=0.0017. The spectrum shows evidence of Balmer series lines in absorption, with a potential weak emission in the H-gamma trough.  

 

This result is not inconsistent with Lipunov et al. (GCN Circ. 20748), who suggest the event to be a CV.