[AZ-Observing] Re: M57
- From: billferris@xxxxxxx
- To: az-observing@xxxxxxxxxxxxx
- Date: Thu, 07 Jun 2007 10:21:22 -0400
Atmospheric seeing is another contributor. The central star is seen against the
subtle nebulosity filling the planetary's annulus. Typically, magnifications of
350X or greater and good seeing are required to make the detection. High
magnification lowers the surface brightness of the background nebulosity
enough to allow the ~15.2 magnitude central star to emerge. If the seeing is
soft, the star bloats and blends into the background nebulostiy. But when the
seeing steadies, the central star pops into view. On nights when the central
star is visible, nearby IC 1296 makes a fine challenge for moderate to large
aperture.
Bill in Flag
-----Original Message-----
From: Stan Gorodenski <stan_gorodenski@xxxxxxxxxxxxx>
To: AZ-Observing <az-observing@xxxxxxxxxxxxx>
Sent: Thu, 7 Jun 2007 12:15 am
Subject: [AZ-Observing] M57
Well, I am certain I have finally seen the central star in M57 with the
6", although I am sure seeing the central star is no big feat for all
ou experienced observers. I never saw it with the 12.5" Dall-Kirkham.
t pretty regularly pops in and out using averted vision. Sometimes it
eems very defined. I am wondering if this may be when it hits a more
ensitive rod in my eye, or because it is on the borderline of
isibility stochastically a times a rod gets hit with a few more photons.
tan
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