sufficient twlight definition/approximation?

Eric Thayer (
Mon, 6 Jul 1998 17:31:47 -0400

Here's something I've been wondering about for a while.  Rather than using a
categorical definition of darkness (e.g. sun more than 5 degrees below
horizon) to determine if conditions are acceptable for viewing, it would be
nice to have a definition that took into account the expected satellite
magnitude (if available).  Something like for a mag Y satellite, the sun
must be at least X degrees below the horizon where Y is estimated the usual
ways and X is computed from Y in some way.

Anyone know of such a thing?