Difference: GCNCIRCULAR21633 ( vs. 1)

K. C. Chambers (IfA), M. E. Huber (IfA),K. W. Smith (QUB),
S. J. Smartt, (QUB), D. R. Young, M. Coughlin (Harvard), T.-W. Chen
(MPE), J. Bulger, L. Denneau, H. Flewelling, A. Heinze, E. Kankare
(QUB), T. Lowe, 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, M. Willman (IfA), D. E. Wright (QUB)

We report continued Pan-STARRS imaging of the transient SSS17a/DLT17ck in NGC4339 in filters i, z and y (see Chambers et al. GCN 21553 for more details of filters, photometry, methods etc).

Our reference stack and calibrations provide rapid reliable photometry with the host removed and we will continue to post updates while it is visible from Hawaii. A series of short exposures to avoid sky saturation in twilight in each of i, z, and y provide average nightly magnitudes (AB) as follows.

Pan-STARRS is observing at lower altitude than it has ever done, Poor conditions and airmass>3 hampered the fourth night of observing (57986 = 2017-08-21 UT). The difference images showed faint flux in z band, but no detection in i and y. The forced photometry in the z-band at the position of the transient is reported. The quick estimates for i and y need to be verified.

MJD i err
57983.23 17.24 0.06
57984.24 17.91 0.05
57985.24 18.47 0.08
57986.24 <18.5 limit only

MJD z err
57983.23 17.26 0.06
57984.24 17.80 0.05
57985.24 18.31 0.06
57986.24 18.27 0.33

MJD y err
57983.23 17.38 0.10
57984.24 17.59 0.07
57985.24 18.08 0.07
57986.23 <18.0 limit only

-- ShaonGhosh - 21 Aug 2017