The Palomar Transient Factory Sky2Night programme. (arXiv:1902.03768v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Roestel_J/0/1/0/all/0/1">J. van Roestel</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Groot_P/0/1/0/all/0/1">P.J. Groot</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Kupfer_T/0/1/0/all/0/1">T. Kupfer</a> (2,3,4), <a href="http://arxiv.org/find/astro-ph/1/au:+Verbeek_K/0/1/0/all/0/1">K. Verbeek</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Velzen_S/0/1/0/all/0/1">S. van Velzen</a> (5), <a href="http://arxiv.org/find/astro-ph/1/au:+Bours_M/0/1/0/all/0/1">M. Bours</a> (6), <a href="http://arxiv.org/find/astro-ph/1/au:+Nugent_P/0/1/0/all/0/1">P. Nugent</a> (7), <a href="http://arxiv.org/find/astro-ph/1/au:+Prince_T/0/1/0/all/0/1">T. Prince</a> (4), <a href="http://arxiv.org/find/astro-ph/1/au:+Levitan_D/0/1/0/all/0/1">D. Levitan</a> (4), <a href="http://arxiv.org/find/astro-ph/1/au:+Nissanke_S/0/1/0/all/0/1">S. Nissanke</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Kulkarni_S/0/1/0/all/0/1">S.R. Kulkarni</a> (4), <a href="http://arxiv.org/find/astro-ph/1/au:+Laher_R/0/1/0/all/0/1">R.R. Laher</a> (8) ((1) Department of Astrophysics/IMAPP, Radboud University Nijmegen, (2) Kavli Institute for Theoretical Physics, UC Santa Barbara, (3) Department of Physics, UC Santa Barbara, (4) Cahill Center for Astronomy and Astrophysics, Caltech, (5) Center of Cosmology and Particle Physics, NYU, (6) Instituto de F&#xed;sica y Astronom&#xed;a, Universidad de Valpara&#xed;so, Chile, (7) Lawrence Berkeley National Laboratory, UC Berkley Department of Astronomy, (8) Spitzer Science Center, Caltech)

We present results of the Sky2Night project: a systematic, unbiased search
for fast optical transients with the Palomar Transient Factory. We have
observed 407 deg$^2$ in $R$-band for 8 nights at a cadence of 2 hours. During
the entire duration of the project, the 4.2m William Herschel Telescope on La
Palma was dedicated to obtaining identification spectra for the detected
transients. During the search, we found 12 supernovae, 10 outbursting
cataclysmic variables, 9 flaring M-stars, 3 flaring active Galactic nuclei and
no extragalactic fast optical transients. Using this systematic survey for
transients, we have calculated robust observed rates for the detected types of
transients, and upper limits of the rate of extragalactic fast optical
transients of $mathcal{R}<37times 10^{-4}$deg$^{-2}$d$^{-1}$ and $mathcal{R}<9.3times 10^{-4}$deg$^{-2}$d$^{-1}$ for timescales of 4h and 1d and a limiting magnitude of $Rapprox19.7$. We use the results of this project to determine what kind of and how many astrophysical false positives we can expect when following up gravitational wave detections in search for kilonovae.

We present results of the Sky2Night project: a systematic, unbiased search
for fast optical transients with the Palomar Transient Factory. We have
observed 407 deg$^2$ in $R$-band for 8 nights at a cadence of 2 hours. During
the entire duration of the project, the 4.2m William Herschel Telescope on La
Palma was dedicated to obtaining identification spectra for the detected
transients. During the search, we found 12 supernovae, 10 outbursting
cataclysmic variables, 9 flaring M-stars, 3 flaring active Galactic nuclei and
no extragalactic fast optical transients. Using this systematic survey for
transients, we have calculated robust observed rates for the detected types of
transients, and upper limits of the rate of extragalactic fast optical
transients of $mathcal{R}<37times 10^{-4}$deg$^{-2}$d$^{-1}$ and
$mathcal{R}<9.3times 10^{-4}$deg$^{-2}$d$^{-1}$ for timescales of 4h and 1d
and a limiting magnitude of $Rapprox19.7$. We use the results of this project
to determine what kind of and how many astrophysical false positives we can
expect when following up gravitational wave detections in search for kilonovae.

http://arxiv.org/icons/sfx.gif