Photoelectric Photometry Newsletter

Report of the AAVSO Photoelectric Photometry Committee

This is the report of PEP observations made by 17 PEP observers in the fiscal year 1997-1998. We had a good year with 2,610 observations, though 106 less than last year.

We have one new photoelectric observer, Dr. Eugene Lopata. He works in the computer chip manufacturing industry and is located near San Francisco, CA. He uses an SSP-3 on his club's 10" SCT telescope.

We did an observing project for a visual observer who felt very strongly that one of the field stars for a variable he was observing was varying by about 0.3 magnitude. He requested through our Director, Dr. Mattei, that we measure the star with PEP. We obtained 33 observations from 3 photoelectric observers that gave a variation of just 0.05 magnitude which we estimated at just over our normal scatter. You may draw your own conclusions on the matter. But we are planning to continue monitoring the star on a low priority basis for perhaps a year.

Sergio Dalaporta of Italy has recorded important data on CH Cygni. He obtained data showing that light through the PEP V filter does "flicker" on a time scale of about 5 minutes with variation of about 0.2 magnitude. A paper to the IBVS is in preparation giving full detail of the observing technique used. One other PEP observer, caught CH Cyg "flickering" too, using our standard observing technique, that showed a very high standard error. That should be expected, but we were surprised by what we saw.

Dr. John R. Percy, University of Toronto, published two issues of the AAVSO Photoelectric Photometry Newsletter. The PEPNL should be read by any PEP observer as it is inspirational and encourages us to continue our efforts on cold dark nights. Thank you very much, John.

Respectfully submitted,

Howard Landis        16 Oct. 98