Statistics from S. Pesci and P. Mazza logbook.

How many observations to make two discoveries ?

I began my visual hunting program in 1991, after some ten years of variable star observing and deep sky. My patrol galaxies were some one hundred circumpolar galaxies, which were suveryed with a 45cm home made Dobsonian.

Slowly my program expanded to the currently 600 brightest and closest galaxies. These are checked on average 10-15 times a year, during 35 to 45 nights (numbers depend much on weather), mostly on weekends and holidays.

Since 1995 Piero Mazza has joined my search with his 40cm home made telescope. We now share the same program and search on same nights dividing our targets. I'm currently using a 51cm telescope.

Our search efforts have produced so far two official discoveries (1995al in NGC 3021 and 1996bk in NGC 5308) and we were late on three supernovae in 1993 and 1994.

In 1997 our combined efforts have logged almost 7,400 observations on a program of 974 galaxies on 49 nights; 576 galaxies were checked more than 5 times during the year. Plans for 1998 include CCD search on moonlit nights when visual hunting is impaired.

The following graph shows the number of observations made since 1991 and the number of galaxies patrolled (left hand scale) and the number of observing nights dedicated to supernova hunting (right hand scale).

Stefano Pesci