{
  "bibcode": "2019GCN.25455....1S",
  "body": "S. Smartt, K. W. Smith, S. Srivastav (QUB), T.-W. Chen\n(MPE), M. Huber (IfA), , K. Chambers (IfA), D. R. Young, O. McBrien,\nJ.  Gillanders, D. O'Neil, P. Clark, S. Sim (QUB), T. de Boer,\nJ. Bulger, J. Fairlamb, C.-C. Lin, T. Lowe, E. Magnier A. Schultz,\nR. J.  Wainscoat, M. Willman, (IfA, University of Hawaii) A. Rest\n(STScI), C.  Stubbs (Harvard),\n\nWe made further observations of the LALInference skymap of the NSBH\nevent S190814bv (The LIGO Scientific Collaboration and the Virgo\nCollaboration, GCN 25324, 25333) with the Pan-STARRS1 telescope\n(Chambers et al. 2016, Huber et al. GCN25356) on MJD 58716.5. \n\nAs described in Srivastav et al. (GCN 25417), we focused on the inner\n50% probability with deep stacks reaching a typical 5-sigma limiting\nmagnitude of z < 22.2. We found one more. previously unreported\ntransient at z = 21.41 +/- 0.15, with details available on the TNS\n(AT2019ofb). \n\nHere we report the photometric evolution of the transient AT2019npv\n(DG19wxnjc), discovered by DECam-GROWTH (Goldstein et al. GCN25393).\nJonker et al. (GCN 25454) measured the redshift of the nearby blue\ngalaxy (PSO J013.3850-23.8322 or GALEXASC J005332.30-234955.3) to be\nz = 0.056, placing it within the distance range of S190814bv. \n\nThe following table contains the z-band photometry reported to date\nand new PS1 measurements. \n\n58710.58   ~20.8    PS1,marginal 2-3 sigma detection in z (mag uncertain)\n58711.3       20.7    DECam (TNS Trans. Report 1507)\n58713.34     20.6    DECam (GCN 25393)\n58713.54     21.3    PS1\n58716.54     21.5    PS1\n\nThe DECam photometry needs checked on 58713.34. The last two PS1\npoints have uncertainties of +/- 0.2 mag. The first has an error of\n0.3 to 0.4 mag. Within the uncertainties, there could be a slow fade\nof around 0.1 mag per day, but fast fading can be ruled out with a\nclear detection on 58716.54. \n\nSpectra of this faint object is still difficult due to the moon\nposition. However it should still be pursued, as this appears to be one\nof the only remaining viable counterpart candidates.\n\nWe note the existence of another possible host galaxy. The transient\nwould be about 40kpc from 2MASS J00533400-2350224, if both were at\nabout ~250 Mpc.\n\n2MASS J00533400-2350224      13.391293   -23.839395   V = 18.6",
  "circularId": 25455,
  "createdOn": 1566565404000,
  "email": "s.smartt@qub.ac.uk",
  "subject": "LIGO/Virgo S190814bv: Further Pan-STARRS z-band observations and AT2019npv photometry",
  "submitter": "Stephen Smartt at Queen's U/Belfast  <s.smartt@qub.ac.uk>",
  "eventId": "LIGO/Virgo S190814bv"
}