Presented
at the 88th Annual Meeting of the AAVSO, October 29, 1999
Abstract
The eye can distinguish
brightness differences as small as ±0.1 magnitude near the limit of vision.
Bright variable stars can therefore be studied effectively without optical aid,
provided such a restriction is satisfied. That conclusion has been confirmed by
backyard observations of the bright Cepheids d Cephei, z
Geminorum, and h Aquilae made during 1998-99
using newly-generated reference charts tied to photoelectric V-magnitudes
rather than the usual “visual” magnitudes included on AAVSO charts. The derived
light curves for the three bright Cepheids exhibit surprisingly little scatter,
and are of potential scientific value for the study of period changes in the
variables.