A Little Astronomy on the Side

I recently returned from a car trip driving from Massachusetts
to eastern Utah and western Colorado. Astronomy was not one of
the motivations behind the trip, but it seemed advisable to
bring a telescope along nonetheless.

I have spent a good deal of time Out West in my life, but
I have made only three trips there after my astronomical
re-awakening six years ago -- and after acquiring a family.
On the first trip, to Arizona, I brought only binoculars,
and bitterly regretted having no telescope, because Arizona
in April had given me access for the first time to two
world-class objects which beg for large aperture and high
magnification: the globular cluster Omega Centauri and the
galaxy Centaurus A (NGC 5128). On this most recent trip,
I wasn't sure that I would miss having a telescope, but
I figured better safe than sorry.

My most recent acquisition seemed like just the scope for
the job: the 100mm F/6 achromat that Orion sells in various
packages under various names. I would think twice (or more)
before bringing it on an airplane trip, but when travelling
by car, I could just tuck it into a corner of the luggage
compartment and forget about it. Anything bigger would
have been prohibitive; our Ford Escort station wagon was
already full-up with complete camping gear for three people,
a half-week supply of food, clothes to cover anything
between 20F and 110F, and a full complement of books and
story tapes to sustain us through the weary hours of driving.

As a mount, I brought my Bogen 3021S tripod, which is short
but sturdy, and the Unistar Light head. The combination
only gets the scope high enough for observing while sitting
on the ground, but I am perfectly comfortable doing that for
an hour or two. Moreover, the low stance makes the scope
admirably stable, whereas it gets pretty wobbly on the
Unistar Light head when used with a Bogen tripod at
standing height. I replaced the stock 6x30 finderscope
with the Orion red-dot finder, which had two benefits.
First of all, the red-dot finder is lighter. Second,
it allows much greater leeway about the placement of
one's head, which is a major issue for such a low scope.
When the scope is low enough to sit on the ground while
using a 90-degree diagonal, you more or less need to lie
down on the ground to sight through the finder. I was
a little sorry to lose the ability to star-hop through
the finderscope, but the benefits far outweighed that.

To complete the rig, my wife had made me a padded carrying
case for the scope as a birthday present. Orion sells no
case that is right to hold the OTA alone, and I had searched
in vain in the local camera stores. My wife assured me
that it would be easy to whip one up on her sewing machine.
I was sceptical, but she was right; the case took only
half a day to build. It has a zippered pocket running
the length of the case and subdivided into compartments
to hold all the necessary accessories: the finder, my
red flashlight, eye patch, UHC filter, 30mm Ultima,
LV 8-24mm zoom, and Ultima barlow. Everything one
could possibly need, short of going to 2" eyepieces,
and all in a container that tucks easily under one
arm, with the tripod in one hand, and charts and warm
clothes in a small day pack.

The warm clothes were very necessary, by the way. Almost
all of our camp sites were above 9,000 feet, several far
above that, and it was a rare morning when there wasn't
frost and/or ice somewhere near the tent. By the time
I had observed for a couple of hours, I was good and
ready to crawl into my warm sleeping bag.

I am always happy to stare at the sky more or less
indefinitely whenever I am outside, day or night but
preferably at night. But in the event, I only brought
the scope out twice, once in the La Sal mountains
east of Moab, Utah and once at Molas Lake north of
Durango. I had a good enough time, but I wasn't
highly motivated for organized astronomy, for several
reasons. First, late June is the pits for astronomy
in the best of circumstances. I am by nature an
early-to-bed type, and staying up past the end of
astronomical twilight in June is a strain for me even
at home, much less when I am travelling and doing
something new and strenuous every day. To make
matters worse, the best stuff in the summer Milky
Way doesn't transit until well after midnight at that
time of year. Basically, anything that can be seen
in June can be seen in much greater comfort, at a
more reasonable hour, in August.

On top of that, the whole point of the trip was to
see and do new things. Actually, that's not
entirely true; half of the activities were things
that my wife and/or I had particularly liked on
earlier trips, and were eager to share with our
daughter. But a lot of stuff, notably the San Juan
mountains in SW Colorado, was new to me. During
the day, I had dozens of new plants, and occasional
new animals, to identify every day, but at night
it was exactly the same sky that I have at home.
The slight advantage due to the more southerly
latitude was very nearly offset by the inferior
horizons from being in the mountains. Comforting
to see the same stars, but not an inspiration
to stay up long past my proper bedtime.

As for the famously good transparency of the Rockies,
it is certainly a fine thing, but it isn't *all* that
much better than the transparency back East after a
cold front comes through. And although the sky at
best is very nearly free of artificial light
pollution, it is for practical purposes no darker
than much of northern New York and New England.
Where the West really has a big advantage over
the East is consistency; instead of having two or
three good nights a month, nights with clouds or
poor transparency are the exception in the summer,
assuming that there are no big fires nearby.
But consistency breeds complacence. Back home,
I am desperate to grab each clear moonless night.
Out West, it is easy to wait until next night.

Finally, I have been doing most of my recent observing
with scopes much bigger than the 100mm scope that I
brought on this trip. I was amused to see Bill Ferris's
article in the Sky and Telescope that was awaiting me
when I got home. Mostly, I agree with the claim
implicit throughout the article -- that given a
choice between aperture and dark skies, it is better
to have dark skies. But in practice, it is all a
matter of degree -- how light the sky and how big
the scope. When observing galaxies under urban skies
or the full Moon, no amount of aperture can compensate.
But under good suburban skies, doubling the aperture
more than compensates for the sky brightness when
viewing most star clusters, and comes close to
compensating on most galaxies. And as for my country
home, probably about average for a rural location in
southern New York or New England, although the light
dome of Albany 20 miles distant fills a whole quadrant
of the sky, the rest of the sky isn't so terrible.
Certainly not nearly bad enough to handicap the 12.5"
Dob that I keep there down to the level of a 100mm
scope under ideal conditions -- not even close!
Using my 100mm scope in Colorado last month, M51
and NGC 5195 showed as two bright disks with very
bright cores. No doubt Stephen O'Meara could see
more, but I am not Stephen O'Meara. Using my 12.5"
Dob under modest rural skies, by contrast, even rank
beginners get a good sense of the spiral arms.

Having said all that, it is still always a pleasure
to browse around in a properly dark sky, even with
a dinky little 100mm refractor; something new always
shows up. Thus, while viewing M6, I noticed the
minor clusters NGC 6416 and 6425 for the first time.
No doubt I could have seen them easily from the suburbs
in my 7" Dob if I had tried, but under dark skies,
they grabbed my eyes when I wasn't trying. No great
revelation, but still something new.

I also had an interesting new perception or mis-perception
while viewing M10. I had always thought of this as a near
twin to M12, perhaps 8' - 10' across by the most generous
reckoning. But when observing it the other night, I noted
that the surrounding sky seems over-rich in faint stars
out to a radius of 15' or even 20'. Is this a subtle
extension of M10's halo, an accident, or an illusion?
Probably some combination of the three. But it was
interesting to see. That is what is so surprising about
astronomy; to see something new in a familiar object
after viewing it more than a dozen times, often with
far superior instruments.

I also spent a while looking at dark nebulae, which I
find are hurt more by modest light pollution than any
other class of object. Telescopically, the finest that
I viewed were the small but intense B92 and B93 on the
edge of M24 -- itself an object which shows surpassingly
well in a small instrument under a dark sky. But for my
money, the finest dark nebula of all in the early summer
sky is the Pipe, which shows nicely (albeit piecemeal)
in a telescope, but far better in binoculars. And under
a good dark sky like the one at Molas Lake, it is also
a fine naked-eye object. In fact, although dark skies
certainly enhance telescopic observing, I always find
that their benefit increases as aperture and magnification
decrease. And the finest sight of all is lying on my
back viewing the summer Milky Way with no instrument at all.

- Tony Flanders

I am always happy to stare at the sky more or less
indefinitely whenever I am outside, day or night but
preferably at night.
- Tony Flanders

Needs no reply! Nice commentary Tony.

Perhaps someday we'll get a chance to share a New England night.

edz

Cumberland,RI