GCN Circular 20518
Subject
LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
Date
2017-01-24T18:15:12Z (8 years ago)
From
S. J. Smartt at Queens U Belfast <s.smartt@qub.ac.uk>
M. E. Huber (IfA), K. C. Chambers (IfA), K. W. Smith (QUB),
D. R. Young, S. J. Smartt, (QUB),, M. Coughlin (Harvard), T.-W. Chen
(MPE), L. Denneau, H. Flewelling, A. Heinze, E. A. Magnier (IfA),
A. Rest (STScI), B. Stalder (IfA), A. S. B. Schultz, C. W. Stubbs
(Harvard) J. Tonry, C. Waters, R. J. Wainscoat, H. Weiland (IfA),
D. E. Wright (QUB)
With Pan-STARRS1, we surveyed the primary northern area of the
LALInference map (LIB_skymap.fits ; Veitch et al., PRD 91, 042003, GCN
20486) following the release of the G270580 alert. Observations began
57774.4 UT and lasted over two further nights. The map of pointings is
uploaded on GraceDB.
Images were taken in the Pan-STARRS i-band in a series of overlapping
45s exposures, with typically 4-8 images at each position. These were
combined into stacks and subtracted from the Pan-STARRS1 3Pi reference
image (Chambers et al. arXiv:1612.05560, and available at
http://panstarrs.stsci.edu). We reach approximately i~21-21.5
depending on the number of images combined.
Using techniques discussed in Smartt et al. (2016, MNRAS, 462, 4094),
we have located and vetted transients with quality filters and a
machine learning algorithm on the images.
In the following table, we give our 124 targets, sorted by magnitude.
The lightcurve trend is given (LC trend), indicating the change in
magnitude between earliest and latest MJD of detection. To select
these targets we required a minimum of 2 detections over 2 separate
nights.
Variable sources which are likely AGN/QSOs or variable stars have, as
far as possible, been removed from this transient list. We remove
likely AGN/QSOs either from catalogues, SDSS DR12 spectra, or nuclear
transients which in galaxies with previous core variability seen in
Pan-STARRS general survey mode. Similarly variable stars or stellar
outbursts are removed through catalogue matching. The following list
is composed of SN-like transients, to the best of our knowledge to
date.
We have removed previously known supernovae (in the preceding weeks
before G270580) from this list. We recover PTSS-17dfn and PTSS-17dgm
from Zhao et al. (GCN 20497,20506 ; the other is outside our field).
The list is sorted by magnitude and we recommend prioritising objects
for follow-up which are rising/falling in their lightcurve.
sn = likely SN, offset from plausible host
nt = nuclear transient. Not obvious AGN, but transient coincident with galaxy core
orphan = no obvious host
Name RA (J2000) Dec (J2000) type current trend Disc. MJD Disc Mag
PS17ua 09 44 11.39 +32 50 36.7 sn fading 00.01 (i-i) 57774.46 17.79
PS17of 10 02 34.60 +44 47 11.2 sn rising 00.07 (i-i) 57774.47 18.53
PS17tn 09 43 13.64 +41 19 02.2 sn rising 00.43 (i-i) 57774.47 18.81
PS17yh 09 59 44.73 +27 38 54.6 sn rising 00.01 (i-i) 57774.53 19.03 PTSS-17dfn
PS17so 09 39 11.89 +45 22 25.9 nt fading 00.01 (i-i) 57774.47 19.24
PS17tp 09 43 15.22 +27 33 07.5 sn fading 00.22 (i-i) 57774.54 19.25
PS17qr 09 30 36.59 +21 24 42.5 sn fading 00.02 (i-i) 57774.51 19.33 PTSS-17dgm
PS17xv 09 58 15.93 +33 28 16.7 sn fading 00.18 (i-i) 57774.47 19.55
PS17yt 10 03 57.96 +49 02 28.3 sn rising 00.54 (i-i) 57774.47 19.71
PS17wt 09 53 23.49 +60 09 31.5 sn rising 00.19 (i-i) 57774.46 19.86
PS17nj 09 50 24.19 +63 35 07.7 nt fading 00.01 (i-i) 57774.46 19.87
PS17ta 09 40 49.20 +27 50 41.2 nt rising 00.01 (i-i) 57774.54 19.88
PS17ve 09 48 07.40 +33 05 12.3 sn fading 00.09 (i-i) 57774.46 19.98
PS17st 09 39 36.56 +46 17 25.1 sn fading 00.10 (i-i) 57774.46 20.00
PS17mc 09 36 03.65 +51 23 16.0 sn rising 00.12 (i-i) 57774.47 20.02
PS17pp 09 21 01.11 +49 27 47.0 sn rising 00.21 (i-i) 57774.48 20.07
PS17mr 09 42 43.78 +42 28 58.9 nt fading 00.06 (i-i) 57774.46 20.08
PS17pt 09 23 31.33 +52 49 13.3 sn rising 00.02 (i-i) 57774.45 20.09
PS17pm 09 18 21.83 +64 43 50.0 nt rising 00.12 (i-i) 57774.46 20.11
PS17va 09 47 39.20 +37 22 27.6 sn rising 00.26 (i-i) 57774.46 20.12
PS17na 09 46 12.72 +60 21 47.8 sn rising 00.05 (i-i) 57774.46 20.20
PS17ra 09 32 04.34 +12 33 51.6 nt fading 00.30 (i-i) 57774.53 20.25
PS17lf 09 27 04.26 +54 23 46.9 sn fading 00.20 (i-i) 57774.46 20.29
PS17xn 09 56 26.51 +37 15 13.8 sn fading 00.31 (i-i) 57774.48 20.38
PS17pg 08 59 59.66 +57 50 26.4 sn fading 00.19 (i-i) 57774.40 20.39
PS17ol 10 06 47.59 +28 01 20.8 sn fading 00.02 (i-i) 57773.62 20.42
PS17ze 10 06 05.38 +53 04 45.1 sn fading 00.11 (i-i) 57774.47 20.42
PS17zj 10 11 15.00 +38 35 57.3 sn rising 00.09 (i-i) 57774.45 20.44
PS17xs 09 57 05.59 +21 58 29.3 sn rising 00.10 (i-i) 57774.54 20.46
PS17sz 09 40 39.32 +23 47 12.2 sn fading 00.06 (i-i) 57774.54 20.47
PS17ov 08 29 57.36 +66 14 08.8 nt rising 00.00 (i-i) 57774.46 20.48
PS17ql 09 29 15.03 +56 00 24.1 sn rising 00.20 (i-i) 57774.46 20.49
PS17vw 09 50 34.59 +25 47 26.9 sn rising 00.12 (i-i) 57774.53 20.49
PS17zf 10 07 01.98 +45 53 40.5 sn rising 00.04 (i-i) 57774.47 20.52
PS17rb 09 32 14.26 +65 26 46.1 sn fading 00.11 (i-i) 57774.45 20.53
PS17us 09 46 33.39 +46 22 07.7 sn rising 00.08 (i-i) 57774.47 20.54
PS17pr 09 21 46.06 +58 12 49.9 sn rising 00.00 (i-i) 57774.45 20.57
PS17sd 09 38 12.65 +16 03 29.6 sn rising 00.14 (i-i) 57774.54 20.58
PS17ss 09 39 30.92 +33 21 15.3 sn fading 00.01 (i-i) 57774.43 20.58
PS17sf 09 38 28.84 +39 46 01.3 sn fading 00.03 (i-i) 57774.46 20.58
PS17qo 09 29 51.26 +44 31 14.6 sn fading 00.08 (i-i) 57774.44 20.60
PS17se 09 38 27.88 +30 03 56.8 sn rising 00.01 (i-i) 57774.47 20.63
PS17xg 09 55 06.39 +27 07 19.6 sn rising 00.13 (i-i) 57774.54 20.63
PS17me 09 37 35.07 +25 35 58.6 sn fading 00.36 (i-i) 57774.54 20.63
PS17on 10 10 22.80 +48 01 28.1 sn rising 00.05 (i-i) 57774.42 20.65
PS17my 09 45 44.55 +20 47 29.5 nt fading 00.13 (i-i) 57774.54 20.67
PS17ui 09 45 33.30 +27 52 23.9 sn rising 00.08 (i-i) 57774.54 20.68
PS17nv 09 57 41.01 +17 49 33.4 orphan fading 00.12 (i-i) 57774.49 20.68
PS17rw 09 36 33.10 +26 22 07.1 sn fading 00.26 (i-i) 57774.54 20.71
PS17rj 09 34 39.14 +51 22 40.6 sn fading 00.07 (i-i) 57774.48 20.71
PS17xo 09 56 30.75 +31 25 47.2 sn fading 00.02 (i-i) 57774.50 20.72
PS17pn 09 18 26.20 +60 41 41.5 sn fading 00.05 (i-i) 57774.46 20.72
PS17vv 09 50 28.24 +29 41 50.3 nt rising 00.05 (i-i) 57774.54 20.72
PS17yi 09 59 48.09 +38 58 58.9 nt fading 00.07 (i-i) 57774.47 20.73
PS17qt 09 30 41.85 +46 20 36.4 sn rising 00.20 (i-i) 57774.45 20.73
PS17xm 09 56 09.82 +26 15 01.1 nt fading 00.12 (i-i) 57774.54 20.74
PS17wy 09 53 53.21 +50 31 08.8 sn fading 00.07 (i-i) 57774.46 20.75
PS17pv 09 25 07.35 +50 12 28.9 orphan fading 00.07 (i-i) 57774.47 20.75
PS17lh 09 29 15.24 +26 47 51.0 sn rising 00.00 (i-i) 57774.52 20.77
PS17xy 09 58 37.81 +29 07 33.6 sn rising 00.23 (i-i) 57774.55 20.77
PS17yq 10 02 49.53 +42 24 00.8 sn rising 00.09 (i-i) 57774.48 20.80
PS17wc 09 51 05.54 +29 22 46.3 sn fading 00.12 (i-i) 57774.54 20.80
PS17ti 09 42 19.84 +21 37 11.1 sn rising 00.02 (i-i) 57774.54 20.80
PS17yg 09 59 44.47 +24 12 03.4 sn fading 00.07 (i-i) 57774.53 20.80
PS17pa 08 38 05.32 +61 24 50.3 sn rising 00.07 (i-i) 57774.42 20.81
PS17pd 08 43 47.07 +64 31 31.4 sn rising 00.15 (i-i) 57774.46 20.81
PS17yj 10 00 16.53 +50 52 03.1 nt rising 00.02 (i-i) 57774.47 20.82
PS17vp 09 49 33.45 +48 49 32.0 sn fading 00.08 (i-i) 57774.47 20.82
PS17ry 09 36 46.35 +26 02 05.2 sn rising 00.02 (i-i) 57774.54 20.82
PS17qk 09 29 12.15 +25 49 06.4 orphan fading 00.20 (i-i) 57774.54 20.83
PS17ud 09 45 03.09 +22 50 09.9 sn rising 00.11 (i-i) 57774.54 20.86
PS17xx 09 58 27.56 +42 53 08.0 sn fading 00.10 (i-i) 57774.48 20.87
PS17qx 09 31 47.56 +12 59 46.8 nt fading 00.12 (i-i) 57774.53 20.87
PS17zb 10 05 56.86 +40 54 27.6 nt rising 00.11 (i-i) 57774.47 20.88
PS17vd 09 48 00.80 +30 06 42.5 sn fading 00.22 (i-i) 57774.51 20.89
PS17wr 09 53 16.55 +51 53 02.8 nt fading 00.09 (i-i) 57774.48 20.89
PS17vu 09 50 16.84 +34 56 19.0 sn rising 00.03 (i-i) 57774.46 20.90
PS17re 09 32 55.07 +52 12 49.5 sn rising 00.31 (i-i) 57774.46 20.92
PS17kv 09 24 01.40 +49 26 03.8 sn fading 00.04 (i-i) 57774.48 20.92
PS17ts 09 43 24.74 +18 08 49.9 sn fading 00.02 (i-i) 57774.54 20.93
PS17xh 09 55 13.67 +46 15 18.9 sn rising 00.10 (i-i) 57774.47 20.96
PS17kr 09 19 46.15 +59 28 37.2 sn fading 00.09 (i-i) 57774.43 20.97
PS17rd 09 32 27.06 +55 40 43.1 sn fading 00.02 (i-i) 57774.46 20.99
PS17vy 09 50 36.23 +22 04 33.8 sn rising 00.03 (i-i) 57774.54 21.01
PS17uo 09 46 11.91 +48 18 56.0 sn rising 00.22 (i-i) 57774.46 21.01
PS17wv 09 53 25.01 +32 39 23.8 sn rising 00.04 (i-i) 57774.47 21.01
PS17tm 09 43 10.54 +34 44 02.2 sn fading 00.08 (i-i) 57774.46 21.02
PS17ue 09 45 06.95 +17 42 19.0 sn rising 00.27 (i-i) 57774.54 21.03
PS17su 09 40 08.78 +23 00 53.1 sn rising 00.07 (i-i) 57774.54 21.04
PS17ku 09 23 44.48 +48 55 06.4 sn rising 00.10 (i-i) 57774.48 21.06
PS17vf 09 48 11.27 +18 20 40.8 nt rising 00.13 (i-i) 57774.54 21.08
PS17vg 09 48 15.51 +29 45 48.7 sn fading 00.03 (i-i) 57774.54 21.08
PS17vt 09 49 57.95 +19 38 47.0 sn rising 00.00 (i-i) 57774.54 21.09
PS17qp 09 30 30.25 +49 52 30.0 sn rising 00.03 (i-i) 57774.47 21.09
PS17rr 09 35 30.85 +16 59 18.1 sn rising 00.04 (i-i) 57774.55 21.10
PS17rz 09 36 57.19 +29 40 06.0 sn rising 00.22 (i-i) 57774.47 21.12
PS17pi 09 05 00.75 +61 01 10.6 sn rising 00.08 (i-i) 57774.45 21.14
PS17xp 09 56 36.86 +49 56 14.1 sn rising 00.12 (i-i) 57774.46 21.15
PS17ph 09 01 00.16 +57 53 49.4 sn rising 00.16 (i-i) 57774.40 21.16
PS17xf 09 55 02.96 +21 14 12.5 sn fading 00.08 (i-i) 57774.54 21.16
PS17vc 09 47 46.66 +41 17 18.0 nt rising 00.13 (i-i) 57774.46 21.18
PS17mp 09 41 52.10 +36 00 40.2 sn fading 00.14 (i-i) 57774.45 21.18
PS17ws 09 53 19.79 +42 26 50.8 sn fading 00.01 (i-i) 57774.46 21.19
PS17uu 09 47 01.91 +17 52 27.1 sn rising 00.03 (i-i) 57774.53 21.19
PS17uw 09 47 10.01 +16 13 51.5 nt rising 00.24 (i-i) 57774.56 21.20
PS17mf 09 37 43.60 +15 23 11.6 nt fading 00.19 (i-i) 57774.52 21.21
PS17lk 09 29 58.27 +15 11 58.5 orphan fading 00.02 (i-i) 57774.53 21.24
PS17xq 09 56 59.17 +27 31 23.2 sn rising 00.07 (i-i) 57774.54 21.24
PS17qq 09 30 35.36 +50 14 34.0 sn rising 00.12 (i-i) 57774.46 21.25
PS17rc 09 32 19.16 +47 03 38.3 orphan rising 00.06 (i-i) 57774.46 21.27
PS17yl 10 00 40.10 +40 39 21.9 sn rising 00.00 (i-i) 57774.47 21.27
PS17ro 09 35 07.03 +23 23 35.9 sn fading 00.00 (i-i) 57774.53 21.33
PS17tv 09 43 41.58 +27 07 59.2 sn fading 00.05 (i-i) 57774.54 21.35
PS17lp 09 31 42.79 +55 37 32.1 sn rising 00.25 (i-i) 57774.45 21.36
PS17mg 09 37 44.15 +17 46 23.5 sn rising 00.01 (i-i) 57774.54 21.37
PS17xk 09 56 08.33 +24 15 22.3 sn rising 00.01 (i-i) 57774.54 21.43
PS17sn 09 39 11.32 +15 24 28.7 nt rising 00.16 (i-i) 57774.52 21.44
PS17qs 09 30 38.38 +16 20 35.0 sn rising 00.12 (i-i) 57774.53 21.45
PS17um 09 46 02.11 +20 57 16.3 sn fading 00.01 (i-i) 57774.54 21.49
PS17qf 09 28 06.94 +16 23 30.8 sn rising 00.46 (i-i) 57774.53 21.50
PS17pk 09 13 47.60 +64 02 59.7 sn rising 00.48 (i-i) 57774.45 21.50
PS17vn 09 49 11.97 +19 17 06.7 sn rising 00.30 (i-i) 57774.54 21.59
PS17tq 09 43 15.46 +16 57 16.2 nt rising 00.12 (i-i) 57774.54 21.69
PS17sr 09 39 26.00 +23 46 04.8 sn rising 00.16 (i-i) 57774.54 21.84