FreeLists / az-observing / [AZ-Observing] Rambling Report: Saturday Night in Southern Arizona

[Tom Polakis <tpolakis@xxxxxxx>]

Jennifer and I were happy to accept Dave Healy's invitation to a
first-light party for his 32-inch Ritchey-Creitien, which was at last
installed 30 months past the target date by Optical Guidance Systems.
Prior to the installation of this scope, his giant dome in southeast of
Sierra Vista was occupied by a "loaner" 20-inch.  The additional magnitude
that the 32-inch provides must have been worth the wait for Dave.

Dave's party began with over 50 people in attendance, mostly from the local
area.  For the first couple hours after dusk, the dome was predictably a
zoo, with much crowd control.  Jenn and I waited in line long enough to see
M17, but decided to come back when crowds had settled.  That they did, and
that's when the fun began.  We were left with five observers: Jeff Medkeff,
who made the seven hour flight from his new home in Alaska, "Mr. Galaxy"
himself Wayne Johnson, who is a pleasure to observe with, Dave, and the two
of us.  A sixth, John Cassella, was present for the earlier observations.

The big telescope slews to objects with the ultimate in GO-TO: speech
recognition  software named Digital Sky Voice listens to your request (most
of the time, anyway), asks you to confirm, and off it goes without the
observer leaving the dome.  The inside of the dome is inky black compared
to the usual star party setting, and that means a lot for dark adaptation.
We were treated to very good seeing conditions and transparency for a night
to file away.

Most of the time we stuck with favorite objects, viewing at magnifications
of 180x, 300x, and 480x.  The surface of the Ring Nebula showed a
blue-green hue, even when viewed at 480x (still 1.8mm exit pupil!).
Observers saw the central star with varying degrees of difficulty.  I found
it to be visible all of the time against a background "hole" that was
brighter than the surrounding sky.

The Saturn Nebula was great at 480x.  Extending from a bright oval core
were two very bright extensions with bulbs at each end.  I have seen most
of this detail through my 20-inch, but always with more difficulty.  I have
never seen the color more evident.  Sticking with planetaries with high
surface brightness, the Little Dumbbell Nebula, M76, was a treat.  The
brightest central region was rectangular, 3:1, showing full loops extending
from both ends of both sides.  Wayne used an Oxygen III filter on the Crab
Nebula.  I had it in my head that this wouldn't improve the view; instead,
the filter brought out filaments and a central "bar" in the nebulosity.

We looked at a couple extragalactic close-ups.  NGC 604 is a giant HII
region in M33.  At 600x, the supergiants of the star cluster that was born
out of the nebula were sprinkled across the region.  Dave put the scope on
NGC 206, a stellar association in the Andromeda Galaxy.  It resolved into a
couple dozen stars at 480x.

We viewed a number of galaxies.  The real eye-opener was M77, whose spiral
arms were obvious, and incredibly detailed.  This galaxy will take any
magnification you want to throw at it.  NGC 7814 is an edge-on with a
razor-thin dust lane that demonstrates the value of averted vision.

Staying up late enough on this October night brought M42 into view as a
closer.  What struck me were the colors: lime green around the cavity that
encloses the Trapezium, rusty red in the shorter "wing" of the nebula, and
neon pink in M43.

Aperture rules.

Tom

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