OR: Fun Night At Bonny Doon

Last night my wife and I went to Bonny Doon Airport, to join the Santa
Cruz Astronomy Club observing on a near first quarter moon. I took my
10 inch Dob, Winter and Spring Night Sky Observers Guide, Sky Atlas
2000, and eyepieces. It was great to "travel light" (no 18", computer,
etc.) - and after only a 15 minute ride up Alba Road then down Empire
Grade, we were there - in time to set up, and take a walk along the
runway as the sun set. The sky was almost perfectly blue - other than a
couple long, very red, contrails over the western horizon.

There were many other telescopes there, including the SCAC's 13.1"
Coulter Odyssey - the big red tube "water heater", and, showing up as I
was talking the walk, Bob K's new 22" Obsession UC. Bob has been trying
to get me to look through his scope, and bring my 18", since last fall,
when his scope arrived new. As night settled in, temperatures stayed
warm - I had only a few layers and a jacket. Hard to believe this was a
January evening.

We began by looking at Jupiter, and showing it to others. Seeing was
very good, maybe an 8 of 10 - just a big of scintillation that would
settle out now and then giving crisp higher power views. I was swapping
between my 7mm and 4mm eyepieces. There were a number of newbies out -
one German guy next to me trying to learn CCD imaging (with an
unshielded laptop - boooo...), another, from Prunedale, who had his
120mm Orion refractor out for only the 3rd time - even Bob is still a
noob - even though he jumped in the deep end with that big new scope. I
was showing off M42, M41, The Mexican Jumping Star (Tau Canis Majoris) -
when we decided to visit Bob.

What ensued will be one of the most memorable views I've ever had. Bob
was looking at M42 with a 21 Ethos in his 22" f/4.2. He asked about
color - asking if I'd ever seen any in the big nebula. I have, but, I
told him, it has always been "tones" of red and blue/green, subtleties,
tonal grays... and I walked up to the eyepiece. After a short time
enjoying the great view - there is no substitute for aperture - this was
a different experience than looking at it in my 10" - I began to realize
I was seeing, in an absolute no question about it sense - colors. There
was no filter on the eyepiece. The first things I noticed were a
greenish glow in the bright nebula surrounding the small black patch
containing the Trapezium stars. The bright nebula was absolutely
green. I was shocked. Then what caught my eye was reds, almost crimson,
in the sections of the wings closest to the Trapezium. The reds faded
quickly along the wings as you'd get further from the bright sections.
Then I realized I was seeing distinct color over the entire expanse of
M43 - it was brownish - something between raw and burnt umber. There
was a brighter bar across M43 I had never noticed, too - running (as
memory serves) SW-NE across the object.

Several of us looked at it, and everyone was seeing the same thing. One
of the newbies remarked that Bob's scope was like having color TV...
LOL... the dude's dating himself with that comment! But its true.
Never, have I seen such obvious and dramatic color. Here is a fairly
nice drawing of the entire region - http://www.asod.info/?p=3766

With the type of light grasp Bob had in the 22, and obviously excellent
transparency we had, I thought about looking for The Horsehead, but - no
H-Beta filters in the vicinity, and no dice when I tried for it.

I brought over several 2" filters for Bob to try - since he didn't have
any. I think the most interesting view was with the 13mm Ethos and OIII
filter - looking at the Trapezium. The blacks behind it were stark,
dead black, with tiny pinpoint stars here and there... but the bright
nebula around The Trapezium glowed in OIII and showed tremendous
mottling - almost like what you'd see in a good view of The Crab Nebula
- but more distinct. Great view!

The Obsession UC handled like a dream. The only complaint Bob had about
it was, it was so light to the touch that if some wind came up, the
scope would not stay on the target. I thought about how sticky/hard the
motion is on my 18". We also were joking that, as long as Bob was going
to be coming out, we'd just leave our scopes home and mooch from him.

Later on, back at my 10", I had a nice view of The Eskimo Nebula -
putting in the 4mm and seeing nice ring structure around the central
star. The seeing was holding up, but still not perfect. Temperatures
were still very comfortable - but some bands of clouds were appearing
over the northwestern horizon.

Realizing the clouds were impending, I gave up my night vision and
looked at Jupiter. More touristas came by - a couple who live in a
house neighboring the airport. When the seeing steadied, the bands and
other detail on the planet became very sharp. All four Galilean moons
were in the same field of view - and one of them was throwing its shadow
on the planet - near one of the higher latitude bands. A nice pinpoint
black dot, that we watched move over time. The woman asked if those are
the moons that Galileo discovered... which led to a bit of discussion
about science and church, in that era.

By this time, the moon was low - it was nearly 10 pm - early by most
standards, but in winter, you can get in a full night observing by that
time. So, with the moon enveloped in a glowing circle of cloud - with
its crescent shape looking like the smile the disappearing face of the
Cheshire Cat, we packed up, and drove out.

It was a fun night at Bonny Doon. And a memorable one. Color TV.... ha!

-- 
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