SN 1987A in the Large Magellanic Cloud. IV - Photometry from the spectrophotometry

Mario Hamuy, Nicholas B. Suntzeff, Jorge Bravo, M. M. Phillips
1990 Publications of the Astronomical Society of the Pacific  
Systematic differences in the UBVRI photometry of SN 1987A exist between the published photometry from CTIO and SAAO. The largest differences occur in the I band where the SAAO photometry is up to 0.4 magnitude brighter than the CTIO photometry. We have measured the filter/phototube response of the CTIO system and have synthesized VRI photometry from the CCD spectrophotometry of SN 1987A obtained at CTIO. The differences between the synthesized and photoelectric photometry for both the CTIO and
more » ... r both the CTIO and SAAO natural systems are less than 0.05 magnitude. This confirms our previous suggestion that the nonstellar nature of the supernova spectrum can give rise to large systematic errors in photometry obtained at different sites. The comparison of the light curves of any two supernovae can be in error by a similar amount due to the different natural photometric systems.
doi:10.1086/132713 fatcat:anp6zsxf4raibmregsvem4c3gm