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Yes, it seems some observers on some occaisons may be seeing stars in the eighth magnitude or less. There is some room for variation in individual perceptions, even though studies have shown the variation in retinal sensitivity is small. Pupil size, exceptional acuity and technique may play more of a role for such gifted individuals. But, as far as taking scientifically useful data for variable stars goes, what is the point of these extraordinary cases? The vast majority of observers who will submit their observations to VSNET or AAVSO will have a NELM around 7.6 at 50% detection. I dont think it is a good idea to suggest observers should strive to make estimates at 5% detection just to go deeper. I have done quite a bit of faint estimations. While sometimes I do detect stars at 5-10%, they seem to "pop" into view infrequently, I do not believe an accurate estimate can be made. In fact, at this low detection rate, I commonly see a fainter comp star appear brighter than a brighter comp star! You just cannot make a reliable comparison based on these "pops" or flashes of view you get. The error on the estimate is probably going to be worse than 0.5 mag at these low detection rates. Why corrupt the database with such poor values? I feel strongly that estimates submitted for archiving should be made at no less than 50% detection. Trying to go deeper is fine for testing your scope, sky or techniques, or friendly competition at a star party, but it has no place in serious data gathering. Mike Linnolt > HD 110275 7.98 0.24 8.1 seen; one or two failures > HD 110408 8.08 0.53 8.2 seen > HD 110104 8.21 1.12 8.3 seen with difficulty > BD+60 1415 8.98 1.35 8.5 glimpsed at intervals; very doubtful Yes, but what would have been their estimate on these!
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