While perusing some light curves I noticed a couple of vis measurements at mag 19 ( to one decimal place!). The comp star claimed was at mag 18.1. I reported these to HQ via zapper and will let the experts decide what to do with them. But I'm wondering how big a telescope is needed to reliably view (with a human eyeball) 19th mag stars? (The key word here is "reliably.")
At the same time I noticed many "less than" measurements in the same range for this star (but as CCD values). Many of these showed no chart nor comp star value. There were also many with comp stars and check stars 5 to 7 magnitudes brighter indicating extreme extrapolation. How valuable can these measurements be? I'm guessing that an experienced researcher would ignore them but is it worth the effort to try to clear them out of the AID?
Jim Roe [ROE]