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Date: 21 Jul 2006 03:16:29
From: Willie R. Meghar
Subject: Lost in Space (Obs.Report)
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Observing sessions come in many forms. Some involve the recording of
meticulous notes. Others are less formal and more relaxed.
The session just ending was of the latter type. All paper, pencils
and atlases were left inside -- intentionally. I simply wanted to
enjoy the night sky without any distractions.
Using alt-az mounted 25x100 binoculars I swept through a small section
of sky including parts of Perseus and Andromeda (OK, so I wanted to
hit the double cluster and M31-32-110) followed by a large section of
sky in the southern direction. Horizontal sweeps began low in the sky
at tree level. Each succeeding sweep climbed a little higher in
altitude.
An advantage to this approach is that the eye sees only star light.
Not even a dim red light, typically used for reading charts or taking
notes, is turned on.
A disadvantage is that objects seen don't get identified and recorded.
Several familiar objects were swept up along with a multitude of
objects that were left unidentified. In addition to the traditional
observing targets, several interesting asterisms (such as linear
strings of stars) as well as some truly awesome Milky Way fields were
swept up.
Sometimes I would hit a Milky Way field that was so bright and evenly
illuminated that it would (big exaggeration here) remind me of day
light. Other fields consisted of a multitude of bright and dim stars
seen against scattered bright Milky Way glows interrupted with a
generous serving of dark nebulae. Some of these fields were quite
spectacular.
Naked eye limiting magnitude at the zenith was a little better than
6.0; but I didn't bring out any magnitude charts that would have
allowed me to arrive at a more precise value. Trees on the horizon
appeared as silhouettes that were *much* darker than the background
sky -- reminding me of some of the photos from Burnham's Celestial
Handbook. Actually, some of the astronomical 'show pieces' looked
very much as spectacular as their (old) black and white photographs.
Tomorrow night, weather permitting, I'll most likely return to
telescopic viewing (including the recording of notes) of objects on my
observing list. There's so much to do and life is so short . . .
Willie R. Meghar
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Date: 21 Jul 2006 18:22:35
From: Martin R. Howell
Subject: Re: Lost in Space (Obs.Report)
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Willie R. Meghar wrote:
> Trees on the horizon appeared as silhouettes that were *much* darker than the background sky
Nicely said and wonderful mental imagery. I have read that a gauge of a
truly dark sky is that clouds, if present, can't be seen as such. .
.they only give themselves away by blocking out splotches of the night
sky's stars. I have never seen skies this dark and can only imagine
their majesty.
--
Martin R. Howell
"The Astro Post"
www.theastropost.com
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Date: 21 Jul 2006 22:58:58
From: Willie R. Meghar
Subject: Re: Lost in Space (Obs.Report)
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"Martin R. Howell" <martinhowell@ilikestarsisp.com > wrote:
>I have read that a gauge of a
>truly dark sky is that clouds, if present, can't be seen as such. .
>.they only give themselves away by blocking out splotches of the night
>sky's stars. I have never seen skies this dark and can only imagine
>their majesty.
Based on my imperfect memory (I tend to not do much stargazing when
the sky is cloudy).
Thin wispy clouds can be difficult to see as such under a dark sky.
Their effect is more of a diffused dimming of the night sky, much like
the effects of atmospheric dust or smoke. The night sky under such
conditions just doesn't quite look as good as it should.
Well defined opaque clouds can be seen not only by the absence of the
stars that are blotted out; but also by the noticeable selective
darkening of the brighter background sky. In other words, even when
positioned in front of a region with just a few faint naked eye stars
such a cloud can be seen as a dark region -- much like a dark nebula
becomes visible due to its brighter background.
A few of us live under relatively dark skies (mine is getting worse,
but so far clouds remain darker than sky for me). I sincerely hope
you get a chance to spend some quality time under a relatively dark
sky. Scanning such a sky with large binoculars, especially regions
that include the Milky Way, will provide views that simply cannot be
duplicated under a brighter sky regardless of how large an aperture is
utilized.
In all seriousness, there is no substitute for a dark sky!
Willie R. Meghar
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