Swift and OSN UV and optical observations of SN 2016P
ATel #8581; Z. Cano (Univ. of Iceland), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), D. Malesani (DARK/NBI), C. C. Thoene (IAA-CSIC) & S. Schulze (PUC, MAS)
on 23 Jan 2016; 12:12 UT
Credential Certification: Antonio de Ugarte Postigo (email@example.com)
Subjects: Optical, Ultra-Violet, Supernovae
We observed the field of the type Ic-BL SN 2016P (Zhang & Wang 2016, Atel #8563) with a Swift target-of-opportunity (1 ks; PI: Cano) around Jan 20.9 UT in UVOT filters U, UVW1, UVM2 and UVW2, and with the 0.9-m OSN (Granada, Spain) telescope around Jan 22.4 UT in filters BVRI. The SN is detected in all optical and UV filters, at a position in the UVOT images of RA(J2000) = 13:57.31.13, Dec(J2000) = +06:05:51.6.
The Swift magnitudes (Vega) are: U=16.74+-0.07, W1=17.00+-0.08, M2=17.14+-0.09, W2=17.18+-0.10. The OSN magnitudes (Vega) are: B=17.16+-0.05, V=16.57+-0.03, R=16.23+-0.06, I=15.97+-0.03. Aperture photometry was performed using a 3'' radius. The OSN magnitudes are calibrated using SDSS standards in the field, whose magnitudes were converted into BVRI using the transformation equations in Lupton (2005). Note that the magnitudes are not corrected for foreground extinction, and are likely affected by some contribution, especially in the UV, from the underlying host (NGC 5374; D=63 Mpc).
Swift simultaneously observed the field with XRT, however no new source was detected at the SN position. We derive a count-rate upper limit of <8 × 10-3 c s-1 (0.3-10 keV). Assuming an absorbed power-law spectrum with Galactic NH = 2.12 × 1020 cm-2 and photon index Γ = 2, this corresponds to a 0.3-10 keV flux limit of <3 × 10-13 erg cm-2 s-1. At a distance of 63 Mpc, this implies an upper limit to the 0.3-10 keV X-ray luminosity of <1.4 × 1041 erg s-1.
We thank the Swift team, in particular the Swift PI Neil Gehrels and the duty scientist Boris Sbarufatti. We also thank the OSN director Susana Martin for accepting our DDT to observe this event, and Victor Casanova for performing the observations. Future observations are planned.