Swift/UVOT upper limits on SN 2017eaw before explosion
ATel #10382; S. Campana (INAF-Brera), P. Kuin (MSSL/UCL)
on 16 May 2017; 20:48 UT
Credential Certification: Sergio Campana (campana@merate.mi.astro.it)
Subjects: Optical, Ultra-Violet, Supernovae
We report on historical Swift/UVOT observations of SN 2017eaw in NGC 6946 (Dong & Stanek ATel #10372).
Swift/UVOT observed several times NGC 6946 over the years.
Summing up all the images on a filter basis, we never detected the progenitor star. We were able to derive 3sigma upper limit as below:
Filter | m_vega | m_AB | Exposure (s)
v | 20.27 | 20.26 | 1529
b | 21.22 | 21.10 | 1679
u | 21.03 | 22.05 | 2334
w1 | 21.61 | 23.14 | 5530
m2 | 21.69 | 23.37 | 5030
w2 | 21.91 | 23.60 | 6067
Upper limits were derived using a 3 arcsec aperture centred on
SN 2017eaw
position. No correction has been made for the reddening of E(B-V)=0.29 (Schlafly & Finkbeiner 2011 ApJ 737, 103).
