I was flying to New York last Saturday morning at 8 am, so headed to
Coe last Friday night for a night of observing before the trip. The
only time I had ever tried a Messier Marathon was the famous
underwater star party at Pacheco back in 1999. I lasted longer than
most that night, with help from a battery powered dew heater built
quickly from Radio Shack parts before the soaking wet night of myth
and legend (see "Swimming a Marathon,
http://observers.org/reports/99.03.20.2.html). However, the fog
rolled across Pacheco around midnight five years ago, and I ended the
night with only 53 objects from the marathon.
I have long since finished the Messier List. Although I check back
on some favorite Messiers nearly every observing session, it has been
years since I have looked at some of the objects. I decided that
last weekend would be a good time to try another Marathon, break in
a new scope, and welcome the spring observing season after a long wet
winter.
I brought both my 14.5 inch Starmaster and a one-month old 105 mm AP
Traveler to Henry Coe on Friday night. I've had the Traveler out in
the backyard a lot looking at doubles, the moon, and planets, and
once to Fremont Peak, but on a night I mostly hunted objects with
larger aperture. Last Friday was the first extended observing I have
done with the scope on a whole range of objects from a dark sky
location.
The Traveler worked great as a Marathon scope. I have it mounted on
an older Vixen Custom D alt-az mount with wooden legs that I bought
used on Astromart. This mount makes it possible to just grab the
scope and push it around without releasing any clutches, very much
like starhopping with a Dob. Once near an object,the slow motion
controls on the mount make it simple to keep the scope centered on an
object, and to make very fine position adjustments with almost no
vibration. The counterweight on the mount means that I don't have to
change balance positions of the scope as I point to different regions
of the sky, or as I switch between different kinds of eyepieces.
Both the scope and mount are also light enough to pick up and easily
move around an observing area. I took advantage of this several times
in the parking lot at Hentry Coe on Friday night. First to see
around the tree that blocked part of the southern sky. Then to
position myself in just the right position to pick off Omega Centauri
near the horizon. Then to observe in the lee of a large truck when
the wind picked up around 2 am. And finally to get the best view of
the last Messier objects just rising from the eastern horizon near
morning. I used an Orion 6x30 erect image finder for star hop
through the entire night, based on the observing order and finder
charts in the Don Machholz Messier Marathon book.
I expected I would miss M74 at dusk in the western sky, and did.
This is one of the toughest setting objects for a spring marathon,
and is located in the brightest portion of the sky from Henry Coe. I
was more surprised at how hard both M110 and M33 turned out to be in
the western sky after sunset. I was able to log both with averted
vision through the Traveler after lots of looking with different
eyepieces, but that's pretty sad for objects that are normally
binocular eye candy when they are better placed in the sky. Once I
was past the first half dozen or so objects, it was pretty easy to
pick off everything else cruising through the much better placed
winter and spring constellations. The pace picked up a bit again at
the end of the list, but mostly because I was worried about getting
everything packed up again, driving home, unloading the scopes,
packing for my trip, and still having time to get to the San
Francisco airport. I logged a total of 108 Messiers through the
Traveler between 7:30 and 3:45 am, missing only M74 at sundown, and
M30 at sunrise.
My favorite views of the night were usually pairs or trios of objects
all visible in the same field of view of the Traveler with a 9 mm
Nagler eyepiece. That combination gives an exit pupil of 1.5 mm, a
magnification of 66x and a field of view of about 1 and a quarter
degrees, a great combination for a whole range of objects in the
Marathon. One of the highlight "double features" of the night was
broad sparkling M35 next to the unresolved puff of the much more
distant open cluster NGC2158. Other nice multiple object views were
the paired open clusters M38 and NGC1907 in Auriga; the view of M105
in an arc of decreasing brightness with NGC3384 and NGC3389; the
M65/M66/Ngc3628 triplet in Leo; the spectacular paired galaxies M81
and M82 in Ursa major; and the classic triangle of galaxies
M84/M86/NGC4388 in Virgo, with a fourth much smaller galaxy
detectable in the middle (NGC4387).
I also enjoyed two pairings of very different kinds of objects in the
same field. The planetary nebula in M46 is a beautiful view against
the backdrop of the rich open cluster. This pairing makes M46 of my
favorite clusters on the list, and one I usually check in on several
times a year during the winter. However, it has been a long time
since I had looked at the Owl Nebula M97. It appeared as a large
round puff with darker interior blotches last Friday. With the
field of view of the Traveler, the large edge on galaxy M108 was
visible as a mottled gash in the same eyepiece field. Although the
dying star and island universe differ in physical diameter by nearly
50,000 times (couple of light years vs. 100,000 light years), their
distance from earth also differs by a roughly similar factor (couple
of thousand light years vs. 45 million light years). The enormously
greater size of the island universe is balanced by its enormously
greater distance, producing a "nebula" that has a similar apparent
size to the Owl Nebula in our own Milky Way.
I only used the 14.5 inch scope occasionally during the night. There
was plenty of time to look at things whiles waiting for summer
objects to rise, so I did a little bit of comparison viewing of M
objects at different aperture, looked up the Arp peculiar galaxy pair
NGC3395/3396 in Leo Minor, and chased down some of the supernova
reported in 2004. (SN2004A was still visible in NGC6207, but I
couldn't split SN2004ab from the bright core of NGC5054). Although I
always like to have a large aperture scope with me if I am going to
take the time to travel to a semi-dark site, on this particular
night, I would have done better to only bring the Traveler. The
extra time required to set up the large Dob meant that I had no time
to wander around the parking lot when I first arrived after sunset.
I would have enjoyed talking with the other observers already there,
but ended up rushed to set up both scopes and get started with the
Marathon as soon as skies got dark. Tearing down, transporting, and
unpacking both scopes back at home also increased the number of
things to be be done to catch my flight, and created an unwelcome
rush at the end of the night.
And for surveying eye candy objects like Messiers, the Traveler was
plenty of aperture for quick, beautiful views. In fact, the bright
objects seen through the Traveler were much more visually striking
than the faint objects chased down with the larger aperture scope. I
think most deep sky observers have a tendency to move up in aperture,
but then to primarily use the increased aperture to hunt ever fainter
objects.The net result is an expanded list of faint fuzzies that are
within the range of the telescope, but lots of eyepiece time gets
spent looking for objects on the edge of visibility, regardless of
aperture. I have done much the same as I moved from a 7 inch to
14.5 inch Dob. (Hunting lots of extraglactic globular clusters in
M31 is a good example of a project that requires aperture, patience,
and a willingness to push the edges of what can be seen with any
given scope). Howevever, an alternative use of aperture is to use
the extra resolving power to see more detail in bright objects. I
have found that the 14.5 inch scope has given me the best views I
have ever had of many bright objects, including globular clusters,
the planets, and the moon itself (see, for example, "High Moon"
http://observers.org/reports/2003.09.13.3.htm). Last fall at LSA, I
also started a project to observe all the objects in the Hubble Atlas
of Galaxies with the 14.5 inch scope. That project is based largely
on the brightest galaxies in the sky, but carefully examining those
galaxies for morphology and structure, and comparing how much can be
seen in the eyepiece compared to the beautiful photographic prints in
the oversize Hubble atlas. That project has already convinced me that
I should go back through all the Messier objects with the 14.5 scope
as well, again focusing on detail and structure visible within the
bright objects. To do that, however, I will pick times that are
optimal for observing each object, and spend lots of time playing
with magnifications, filters, and eyepieces as each object is as
close as possible to the zenith.
Some final conclusions after finally doing most of a Messier Marathon.
1) The Messier Marathon is obviously not the best way to actually
observe the Messier objects. There is not enough time to study each
one in detail, or to explore all the other interesting objects
nearby. By design, many of the objects are just setting or just
rising, and so are only detectable rather than beautiful. We all
know that objects are best observed when they are high in the sky.
But there is nothing like seeing some of the best objects in the
heavens reduced to dim nothings to remind you to design your
observing sessions around what is actually UP, not just above the
horizon.
2) The Marathon has the huge compensating virtues of providing a
one-night overview and summary of the sky. It is a great way to
revisit favorites you have seen before, and to compare the sizes,
shapes, brightness, concentration of lots of different galaxies,
open clusters, nebula, and globulars in a single session.
This overview aspect of the Marathon struck me again when I arrived
in New York City last Saturday, and spent Sunday afternoon going
through galleries of the American Museum of Natural History with my
old college roommate. There were tons of exhibit rooms at the museum
that were organized around geographical area of the world, or
animals of a particular type. However, one of the most striking
exhibits was the much newer Hall of Biodiversity. The highlight of
this exhibit was a spectacular wall nearly completely covered with
all kinds of animals from a whole range of different groups.
Related animals were grouped in columns, allowing you to compare the
diversity of form within mammals, or birds, or insects, or
crustaceans, or molluscs, etc; as well as the differences and
similarities between animals in different columns (see
http://www.the-scientist.com/yr1998/august/aug_art/am_mus.jpg for
some idea of the juxtaposition, though the wall itself is only
visible in the background). Looking at everything together in one
giant display was a very different experience than the more detailed
look at more focused exhibits on individual groups. But studying
everything together on that wall also gave a much better overview of
the overall diversity of life on earth, and relationships between
different groups.
The Messier Marathon provides a similar Hall of Astrodiversity for
astronomers. A great overview of both the major types of objects,
and the tremendous diversity of objects within each class. And the
whole night drives home again the large scale structure of our own
galaxy.The early part of the Marathon is dominated by open clusters
and emission nebula as we look outward into an arm of the MIlkyWay
seen in the winter constellations. Then the galaxy rich regions of
the sky emerge in the Spring constellations, as we look away from the
dusty plane of our own galaxy. The night ends with an overwhelming
number of clusters, nebula, and globular clusters as we stare towards
the center of the Milky Way. The concentration of globular clusters
on one side of the sky provided a key part of Shapley's original
argument in 1918 that the sun and earth was located far from the
center of the Milky Way. Going through the Messier Marathon forces
you to think again about our position in the Galaxy, in the same way
as the Hall of Biodiversity forces you to think again about our
position and relationship to the long history of life on earth. I'm
glad to have seen both overviews in a single weekend, despite the
rush of both observing and travel.
-David Kingsley
Received on Sat Mar 27 15:54:59 2004
