Re: (IAAC) Obj: M4 - Inst: Orion 6" Dob

Interesting.  I, too, have noticed that even though M4 is a very bright
object in dark skies, it becomes surprisingly shy in even moderate light
pollution.  My impression is that M4 fades much more than other objects in
light pollution.  Maybe it's because M4 is low and light pollution tends to
make the skies disproportionately bright near the horizons.  A difference in
1 magnitude in limiting magnitude seems to make the difference between a
bright dazzling globular and a faint smudge in which the famous bisecting
line of stars is barely visible.
                                Clear skies,
                                Bill Bryson
-----Original Message-----
From: William L. Schart <wschart@usa.net>
To: Internet Amateur Astronomers Catalog <netastrocatalog@latrade.com>
Date: Thursday, August 27, 1998 12:15 PM
Subject: (IAAC) Obj: M4 - Inst: Orion 6" Dob
>Sky appears as a velvet grey tonight.
>Due to this, M4 only appears as a faint smudge.