I am getting data from BSM_Berry5 and the data includes ZS filter data. Is this filter the same as Sloan Z. Why is it listed as ZS instead of SZ like the other sloan data SR, SG, SI. Just looking for clarifcation.
The sequence for V4371 Oph includes photometry for the Z filter, so is the ZS filter the same as Z.
Hi Mike,
Sorry for the late reply.
The original Sloan survey included a z’ filter (AAVSO calls this “SZ”), which was a IR longpass filter that started around 850nm and went past the silicon sensor limit around 1000nm. This looks like the following:
(from CFHT)
It turns out that there is a major atmospheric absorption feature around 950nm that is included in the original Sloan filter. Panstarrs divided the Sloan bandpass into two: a “z-short” which covers the region prior to the absorption, and a “Y” which covers the region beyond the absorption out past the silicon limit. Ben Granett created a plot that shows this:
AAVSOnet uses the Panstarrs z-short filter, and calls it “ZS”. APASS uses the z-short filter, but calibrates it vs. the Sloan z’ filter; yet another story. So use Sloan magnitudes for the comp stars, even though the z-short filter is narrower.
Arne
