How faint can your scope go?

"Martin R. Howell" wrote in message
.. .

In Rat's post of 9/7/04, he remarked on his observation of the Ring
Nebula:

snip
M57 (of course) - Ring Nebula - PN - LYR - Wow, This is too fun! I
noticed
a couple of faint stars, coming in and out of view, lying just outside
the
ring (in addition to the Mag 13 one that I usually see), I am going to
check later and see what Mag they were.
unsnip

On nights of exceptional seeing conditions, why not fully dark adapt
your
eyes and see just how faint your scope can go? I have posted an image
which labels the stars in the immediate area of Messier 57 with their
magnitudes on my website. My 12.5 inch dob has revealed the 14.7
magnitude
star and using averted vision I can sometimes convince myself that the
neighboring 15.3 magnitude star is hinting at its presence.

To see the image, go to http://home.earthlink.net/~martinhowell and
click
on "Other stuff"


Martin

....and the central star???

--
Jan Owen

To reach me directly, remove the Z, if one appears in my e-mail address...
Latitude: 33.662
Longitude: -112.3272

Jan Owen posted:

On nights of exceptional seeing conditions, why not fully dark adapt

your

eyes and see just how faint your scope can go? I have posted an image
which labels the stars in the immediate area of Messier 57 with their
magnitudes on my website. My 12.5 inch dob has revealed the 14.7

magnitude

star and using averted vision I can sometimes convince myself that the
neighboring 15.3 magnitude star is hinting at its presence.

To see the image, go to http://home.earthlink.net/~martinhowell and

click

on "Other stuff"


Martin


...and the central star???

-- Jan Owen

The Central star is about magnitude 15.0, but it takes high power and *very*
stable seeing to pick it up. Seeing variations can make its tiny Airy disk
blend into the glow in the interior of the ring. It tends to vanish unless
the seeing is rock-solid, and often is observed to 'flash' on and off with
seeing variations. I have seen it in a NexStar 9.25GPS, but it was *very*
marginal. It should be not terribly difficult in a 12 inch, but again, if the
seeing isn't very good, it won't be visible in any aperture. Clear skies to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

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"David Knisely" wrote in message
news
Jan Owen posted:

On nights of exceptional seeing conditions, why not fully dark adapt

your

eyes and see just how faint your scope can go? I have posted an
image
which labels the stars in the immediate area of Messier 57 with
their
magnitudes on my website. My 12.5 inch dob has revealed the 14.7

magnitude

star and using averted vision I can sometimes convince myself that
the
neighboring 15.3 magnitude star is hinting at its presence.

To see the image, go to http://home.earthlink.net/~martinhowell and

click

on "Other stuff"


Martin


...and the central star???

-- Jan Owen

The Central star is about magnitude 15.0, but it takes high power and
*very*
stable seeing to pick it up. Seeing variations can make its tiny Airy
disk
blend into the glow in the interior of the ring. It tends to vanish
unless
the seeing is rock-solid, and often is observed to 'flash' on and off
with
seeing variations. I have seen it in a NexStar 9.25GPS, but it was
*very*
marginal. It should be not terribly difficult in a 12 inch, but again,
if the
seeing isn't very good, it won't be visible in any aperture. Clear
skies to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/


Yes, the central star tends to both seeing and aperture dependent.

I have seen it in a number of different scopes, but never in anything
below 10", and most often above 12.5", so you are doing something right
with that SCT. And we do have some decent seeing here in Arizona...

But because 12.5" is right at the edge of being able to see it more often,
that's why I was curious as to Martin's experiences. He has bracketed it
in his other observations, if, again, somewhat marginally,
magnitude-wise, so I thought I would ask whether he's seen the central
star with the same scope...

--
Jan Owen

To reach me directly, remove the Z, if one appears in my e-mail address...
Latitude: 33.662
Longitude: -112.3272

On Tue, 7 Sep 2004 21:22:35 -0700, Jan Owen wrote:


But because 12.5" is right at the edge of being able to see it more often,
that's why I was curious as to Martin's experiences. He has bracketed it
in his other observations, if, again, somewhat marginally,
magnitude-wise, so I thought I would ask whether he's seen the central
star with the same scope...


Hi Jan,

The central star continues to elude me. There have been a few occasions
when I could, if I were less demanding of my observations, claim to have
seen the star. . .but truth be told, apparently my timing is off. Clear
and moonless skies with really quality seeing conditions are tough to come
by up here in Lake Stevens. Reducing the odds even more is the fact that
for more than 8 years, I have worked a 10:00 p.m. to 6:00 a.m. shift with
an obligatory 2 nights off per week. However, my friend Tom Wales has
located a really dark location about 45 miles away and we may go there next
week and, if so, I'll give it another shot.


Martin

Martin R. Howell wrote:

On Tue, 7 Sep 2004 21:22:35 -0700, Jan Owen wrote:

But because 12.5" is right at the edge of being able to see it more often,
that's why I was curious as to Martin's experiences. He has bracketed it
in his other observations, if, again, somewhat marginally,
magnitude-wise, so I thought I would ask whether he's seen the central
star with the same scope...

Hi Jan,

The central star continues to elude me. There have been a few occasions
when I could, if I were less demanding of my observations, claim to have
seen the star. . .but truth be told, apparently my timing is off. Clear
and moonless skies with really quality seeing conditions are tough to come
by up here in Lake Stevens. Reducing the odds even more is the fact that
for more than 8 years, I have worked a 10:00 p.m. to 6:00 a.m. shift with
an obligatory 2 nights off per week. However, my friend Tom Wales has
located a really dark location about 45 miles away and we may go there next
week and, if so, I'll give it another shot.

Martin

I've seen it clearly, with direct vision. But, it was through the FPOA's
30" scope... :-) I guess I don't stand a chance with my own 8". :-(

- Alex