Cottonwood report, TV76, 8/6/04

Note: This is the full report from Friday evening. My comments on the
supernova posted yesterday are repeated.


Date: Friday evening, 6-Aug-2004
Location: Cottonwood campground, Joshua Tree National Park, California
Equipment: Tele Vue 76 (3" f/6.3) refractor

Have a good two hour window of dark between the end of astronomical
twilight and moonrise tonight so drove up to Cottonwood with the TV76.
Only one other person in the upper loop. Lovely quiet evening.

My first target was the new supernova SN 2004dj in galaxy NGC 2403.
But at the end of astronomical twilight the galaxy was only 13=B0 above
horizon just west of due north. Not very well placed at all. But using
the TV76 the galaxy itself was fairly easy to see. A soft oval glow.
Using the AAVSO finder chart i carefully matched the brighter
foreground stars to my eyepiece view. Through the 3-6mm Nagler zoom
set at 6mm the two stars on either side of the galaxy core were
plainly visible. Then bingo... the supernova! At first it would pop
into view then i'd loose it. But with practice i could hold it
reliably at 80x. Wow! Now neat! Using the 10mm Radian for 48x i could
just catch fleeting glimpses of the supernova. I'm sure during another
time of year when NGC 2403 is higher in the sky that the supernova
would be quite an easy target.

Globular cluster M53 in Coma Berenices hoping to find faint nearby
globular NGC 5053. But no luck on 5053. Skyglow from cities to the
west didn't help. There is an interesting little string of mag 6 star
just north of M53 and a cute mag 9 or so double just south.

Not too far away in Bo=F6tes i did find globular NGC 5466. Fairly easy
in the TV76. No central core visible. Looks more like a round galaxy
than a globular. Between NGC 5466 and M3 i tried to find galaxy NGC
5375 but was unsuccessful.

Revisited planetaries NGC 6543 in Draco and NGC 6826 in Cygnus. The
nebulas themselves don't look that much different than they do in my
home skies. However from Cottonwood the background sky is much darker
and many more fainter field stars are visible. Just a much more
pleasing view. Tried to find NGC 6552 in Draco but the little mag 14.5
galaxy was just too faint for the TV76.

Spent some time looking for the Cocoon nebula, IC 5146, in Cygnus but
it was totally invisible. Tried both with and without UHC filter with
no luck. I could see open cluster NGC 7209. But what was really neat
in the area was dark nebula Barnard 168! A straight dark wall maybe 2=B0
long. Very plainly seen through the TV76 at 30x using the 16mm Nagler.
Really neat looking. Plainly visible with 10x42 binoculars as well.

A bit of random wandering... Veil nebula (both halves), the Dumbbell
M27, M73, and the Coathanger with open cluster NGC 6802 off the
eastern end.

Tried to resolve the NGC 281 trapezium in Cassiopeia. With the 3-6mm
zoom at various settings i can see a brighter pair and a third dimmer
member off to one side. But at 11pm is still only about 30=B0 above the
horizon. Perhaps later in the year i'll revisit and see if i can
resolve the members a bit better.


-Florian
Stargazing.com

On Sun, 8 Aug 2004 21:45:09 -0700, "Florian"
wrote:

Note: This is the full report from Friday evening. My comments on the
supernova posted yesterday are repeated.


Date: Friday evening, 6-Aug-2004
Location: Cottonwood campground, Joshua Tree National Park, California
Equipment: Tele Vue 76 (3" f/6.3) refractor


Hi Florian,

What would you estimate your Limiting Magnitude at cottonwood? I live
a couple hours away and wanted to see if it was worth the drive than
my usual place. Many thanks!

What would you estimate your Limiting Magnitude at cottonwood? I live
a couple hours away and wanted to see if it was worth the drive than
my usual place. Many thanks!


Probably around mag 6. But i don't usually check. Bortle class 4 matches =
pretty close...

Class 4: Rural/suburban transition. Fairly obvious
light-pollution domes are apparent over population centers in
several directions. The zodiacal light is clearly evident but
doesn't even extend halfway to the zenith at the beginning or end
of twilight. The Milky Way well above the horizon is still
impressive but lacks all but the most obvious structure. M33 is a
difficult averted-vision object and is detectable only when at an
altitude higher than 50 degrees. Clouds in the direction of
light-pollution sources are illuminated but only slightly so, and
are still dark overhead. You can make out your telescope rather
clearly at a distance. The maximum naked-eye limiting magnitude
is 6.1 to 6.5, and a 32-cm reflector used with moderate
magnification will reveal stars of magnitude 15.5.

The times i've tried to see M33 naked eye i've failed. Light from the =
Coachella
Valley to the west is quite bright. Also some light from Mexicali far =
south. But
overhead and north and east are dark.

-Florian