The Carnegie Supernova Project. I. Third Photometry Data Release of Low-redshift Type Ia Supernovae and Other White Dwarf Explosions (vol 154, 211, 2017)

In Table 1 the declination of SN Q2005ku should read .00:00:49.3. The arithmetical sign was wrong. In Table 4 the i-band color term should be identically zero. Revised versions of Tables 1 and 4 are given here in their entirety. In Table 4 note the two different values of the J-band color term for the duPont telescope. Only one was given in the original published version of this paper (Krisciunas et al. 2017a). This omission has already been noted in a published erratum (Krisciunas et al. 2017b). 2. Field Star Photometry of Our Supernovae David Rubin, presently at the University of Hawaii, kindly pointed out a problem with Table 5 of our paper. Rubin compared PanSTARRS photometry of field stars with our photometry. He found no problems with the g′r′i′ data. Then he used nonlinear color transformations to compute (i.e., predict) V-band values and used nonlinear transformations and incorporated u′ − g′ as an extra color to compute B-band values. There were no problems revealed in the preliminary BV photometry of field stars presented in CSP-I Data Release 2 (Stritzinger et al. 2011), but Rubin found systematic errors in our B- and V-band photometry presented in the third (and final) data release paper of CSP-I (Krisciunas et al. 2017a). We have identified the cause of the problem. Recall that the procedure for our natural system photometry is: (1) Observe fields of standard stars at a range of air masses, and derive color terms and extinction coefficients. (2) Invert the color equations and transform the standard Sloan u′g′r′i′ photometry (Smith et al. 2002) and BV magnitudes (Landolt 1992) into CSP natural magnitudes. (3) Calibrate our local sequence stars relative to these natural magnitudes. Note that there are no color terms to deal with here, only extinction coefficients and nightly zero-points. (4) Calibrate supernova photometry relative to local sequences. Supernova photometry is therefore in the natural system of the telescope and camera. (5) Reapply the color terms to convert local sequence star photometry into the standard system for publication. (Table Presented). The mistake happened in step number 5. Thus, if one wishes to use our BV photometry of field stars in the standard system, one should use the revised values in the accompanying table. It is important to note that our SN photometry (which is in the natural system) is not affected by the error described here. An abbreviated version of Table 5 is given here. The full machine readable table will be available online. © 2020 Institute of Physics Publishing. All rights reserved.