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GCN Circular 20519

Subject
LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
Date
2017-01-24T20:49:27Z (7 years ago)
From
Chris Copperwheat at LJMU ArI <c.m.copperwheat@ljmu.ac.uk>
From C.M. Copperwheat , A.S. Piascik and I.A. Steele (Liverpool JMU)
on behalf of a larger collaboration.

We report the following Liverpool Telescope follow-up observations of
EM candidates reported to the collaboration by other groups.
Observations were made with the SPRAT spectrograph, and supernova
classifications were obtained using SNID (Blondin & Tonry, 2007, ApJ,
666, 1024).

The following transients were originally reported in GCN 20493.

MASTER OT J063256.50-212333.4 was observed on 2017-01-22 at 21:47 UT.
We find this object has faded considerably, measuring an unfiltered
magnitude of > 20 in the acquisition image, suggesting it has faded
back to or close to its quiescent brightness, reported in GCN 20493 as
20.7. This would be consistent with their tentative classification of
this object as a UVCet flare.

MASTER OT J072347.17+041144.0 was observed on 2017-01-22 at 22:39 UT.
We find a faint object at these coordinates, with an estimated
unfiltered magnitude of ~20.5 based on the acquisition image. No
spectrum was obtained.

MASTER OT J073310.71-012307.3 was observed on 2017-01-22 at 23:04 UT.
We find a featureless spectrum consistent with the tentative
classification of this object in GCN 20493 as a dwarf nova outburst.

MASTER OT J075227.62+113311.6 was observed on 2017-01-22 at 23:29 UT.
The spectrum we obtained is fairly poor but there is some evidence of
emission features, consistent with the tentative classification of
this object in GCN 20493 as a QSO flare.

MASTER OT J073330.60+203432.7 was observed on 2017-01-23 at 00:01 UT.
We find a faint object at these coordinates, with an estimated
unfiltered magnitude of ~21 based on the acquisition image. No
spectrum was obtained.

MASTER OT J081506.13+381123.3 was observed on 2017-01-23 at 00:26 UT.
The spectrum is consistent with a SN Type Ia at +8 days, with z=0.057.

MASTER OT J081016.59+335347.5 was observed on 2017-01-23 at 01:44 UT.
We do not detect a transient distinct from the host galaxy emission.

MASTER OT J074554.47+283123.8 was observed on 2017-01-23 at 23:47 UT.
We detect no transient in the acquisition image at the object
coordinates. We estimate the limiting magnitude of this exposure to be
~20.7.

MASTER OT 103001.37+680122.3 was observed on 2017-01-24 at 00:19 UT.
We find a featureless spectrum consistent with the  tentative
classification of this object in GCN 20493 as a dwarf nova outburst.


In addition, candidate PTSS-17dfn was reported in GCN 20497. We
observed this transient on 2017-01-24 at 01:49 UT. The spectrum is
consistent with a SN Type Ia at maximum, with z=0.085.


-- 
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C.M.Copperwheat
Astrophysics Research Institute,
Liverpool John Moores University
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http://telescope.livjm.ac.uk
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Email: c.m.copperwheat@ljmu.ac.uk
Tel: +44 (0)151 231 2914
Fax: +44 (0)151 231 2921
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