Thursday morning started with the Astronomical
League Business Meeting. Following this informative
event, Ray Berg of the American Association of Variable
Star Observers' Mentoring Program reported on his technique
for "Computer Aided Variable Star Observing". Mr. Berg
started by describing the time-honored "manual" observing
technique. This involves using standard AAVSO star charts,
star-hopping to the variable, making the measurement,
and recording the data. The next day the recorded observations
had Julian Day added and were copied onto the official
report form for mailing to AAVSO Headquarters.
Mr. Berg realized that this processes
could be shortened with a computer. He also upgraded
his telescope to a computer-controlled Meade LX-200.
Connecting the computer to the telescope, he can instruct
the computer to begin an observing sequence. The computer
will point the telescope at the first star on his list.
The computer will display information about the star,
its position in the sky, the Moon's position, and more.
He then makes his estimate and keys it into the computer
including what comparison stars were used. The computer
then moves the telescope to the next target and the
process repeats.
The data is stored onto the hard drive
immediately. Every month, the computer sorts the data,
adds the Julian Day, and e-mails it to AAVSO headquarters.
Hard-copy reports can also be generated. Mr. Berg feels
this has increased his eyepiece time from 10% to 90%
of his observing session.
 The
next talk was also about observing with Alan Goldstein
of the National Deep Sky Observing Society (NDSOS) who
talked about a deep sky "Walkabout". Mr. Goldstein defined
deep-sky as Alpha Centauri and beyond. He first talked
about the most obvious objects in the sky, the stars.
In his walkabout, he advised observing stars that had
some particular value. They might have a particular
spectral type or a particular brightness. You can also
look for extreme stars. These may be very young stars,
very old stars, exploding, varying, or others. It makes
it more interesting to know some physical property of
the stars you are looking at.
The next stop on the walkabout was
the open star clusters, many of which are visible in
binoculars. There are also the larger and more diffuse
associations that can be observed. Globular clusters
were next. These are usually more telescopic than binocular.
Globular clusters are more yellowish than open clusters
since they are younger. Some globulars can be resolved,
but many only appear as a blob.
Continuing on, we come to the emission
nebula, large clouds of gas glowing from re-radiated
ultraviolet light from a nearby star. These nebula sometimes
have dark globules in front of them. Viewing these filters
is often enhanced with a nebula filter. Reflection nebula,
the next class of objects, are not helped by nebula
filters. These objects normally appear blue or white
in photographs. They are formed by dust and gas reflecting
the light from nearby stars rather than absorbing it
and re-emitting it. The Pleiades' nebula is a prime
example, but it can only be seen in the best conditions.
Dark nebula are next. These dust clouds
are similar to those already mentioned, but they do
not have any stars nearby to illuminate them. They usually
only appear as dark areas in front of any of the objects
we have already visited.
Planetary nebula were visited next.
These are gas clouds blown off a central star near the
end of its life. These are typically now white dwarf
stars, but were red giants when they started shedding
their outer atmosphere. That outer atmosphere is now
moving out into space forming the planetary nebula.
Two examples of these are the Ring Nebula (M57) and
the Dumbbell (M27). Another star-death nebula group
is the supernova remnants. These are composed of most
of the atmosphere of a giant star that has been blown
off during the supernova explosion. Typical of these
are the Crab Nebula (M1) and the Veil Nebula.
Our last stop are the galaxies. These
are very interesting since we can see the many different
shapes in which they come. They may be spiral, elliptical,
cigar shaped, or just irregular. They come in many sizes,
from naked eye to tiny telescopic objects. They also
clump into groups, and you can view clusters of galaxies,
like the Virgo Cluster.
 Lunchtime
brought a catered meal followed by the keynote speaker,
Dr. J. Richard Gott III who guided us through "Time
Travel and the Beginning of the Universe".
Dr. Gott discussed the possibilities
of time travel. The primary technique was to travel
through wormholes that connect current space-time with
past space-time. This would allow you to visit the past
over and over again. He also discussed how space-time
in the early formation of the universe may also have
had time-travel wormholes.
Having been whisked through time,
we were brought back to the present by Bob Gent and
Tim Hunter who gave "An Update from IDA - The Battle
to Preserve Our Night Skies". For information on the
International Dark Sky Association's efforts, please
visit the IDA website at www.darksky.org.
Next Dr. Suketu Bhavsar discussed
"Einstein's Universe, Escher's Art". Dr. Bhavsar first
showed us the movie "Power's of Ten" to put infinity
and infinitesimal into perspective. He then reviewed
the expansion of the universe and showed one of Escher
drawings that showed a waterfall being fed from an aqueduct
that was fed by the waterfall. Each part of this drawing
was locally correct, but the global view was impossible.
 This led to a discussion of General Relativity's curved space
that would allow a seemingly impossible thing to happen.
The curve of space in general would tell you if you
lived in an open or closed universe. If we could accurately
measure the angles in a triangle, we could determine
if the universe was open, flat, or closed. Dr. Bhavsar
then showed another Escher illustrating the point.
The final talk was Alan Goldstein
(NDSOS) on "Advanced Observing Skills". Alan Goldstein
founded the National Deep Sky Observers Society (NDSOS)
in 1976 and still leads it today. He started this organization
after observing the usual deep sky objects many times.
Mr. Goldstein realized that he needed to become an advanced
observer and banding together with others in the same
predicament would help him do that. The NDSOS promotes
advanced observing through specific observing programs.
These observing programs force the
observer to keep a detailed log and even make sketches
of the objects being observed. This allows them to compare
older observations with more recent ones and learn from
them. Just as an astrophotographer must make accurate
and detailed notes on their photos to help them take
future images, visual observer must carefully record
what they have seen so they will learn to see the sky
better in the future.
There are a number of projects the
NDSOS promotes. Here are some of them:
- Observation of the position angles and separation
of double stars.
- Making magnitude estimates of variable stars.
- A cluster magnitude chart to determine your magnitude
limit for that night. For example, chart M-6 with
a 6- to 8-inch telescope.
- Pushing the visual limit of your telescope.
- An in-depth study of a particular constellation
or section of the sky.
- Observing detail in planetary nebula.
- Working through Barnard's Catalog of Dark Nebulae.
This is best done with rich-field telescopes or binoculars.
- Observing and recording the spiral structure of
galaxies.
- Looking for globular clusters around external galaxies.
- Searching for supernovae in external galaxies.
- Sketching peculiar galaxies.
- Locating obscure objects - ones observed by few
other observers.
To really improve your observing skills,
you need to immerse yourself in the project as if you
are going to write an article on it. But no matter how
much you get involved in the project, you still need
to have fun doing it or you will lose interest.
Sunset brought the Star-B-Que. The
resort set up tables on the front lawn and fed everyone
a delicious dinner. Afterward, the Star Gazer, Jack
Horkheimer entertained us with a few funny stories and
then showed us his "Antique Computer Films". These films
were produced in 1972 to accompany the science textbook
"Explorations in Time and Space" by M.L. Meeks and demonstrate
basic astronomical principles. These short films (typically
seven minutes long) were produced on an IBM 360/75 with
a Calcomp Microfilm Recorder.
The first film demonstrates planetary
motion and the three Keplerian Laws. The first law states
that all the planets travel in ellipses with the Sun
at one focus. The second law (Law of Equal Areas) states
that a line from the Sun to a planet will sweep out
equal areas in equal time intervals. The final law states
that the square of the time a planet takes to orbit
the Sun is proportional to the cube of the average distance
to the Sun. The film Mr. Horkheimer showed demonstrated
planetary motion and Kepler's three laws. The amazing
thing was these films were created when computer graphics
were just beginning to come into existence.
In addition, Mr. Horkheimer showed
a tape showing the motions of stars. This film first
showed proper motion, the motion of stars relative to
the Sun caused by the stars moving around in and with
the Milky Way galaxy. The next segment showed the parallax
motion of stars. This is the "wiggling" motion of stars
in high resolution position studies. Every year as the
Sun circles the Earth, it makes a the star to appear
to move in a small circle on the sky, moving in the
opposite direction from the Earth.
Another film focused on star clusters.
One aspect was the motion of the individual member stars
of an open cluster and how they slowly move away from
each other over time. The film then allowed us to "fly
around" a model of globular cluster and see its structure
in three dimensions.
Double stars were the subject of the
final film. The first part showed a close-up of the
orbit of the binary star Xi Ursa Majoris. By carefully
observing the positions of Xi and its secondary over
a period of time, we can discover the parameters of
the orbits of the binary stars. How the orbit appears
to us depends on both the physical parameters of the
orbit and the way it is oriented relative to our line-of-sight.
The eccentricity of the orbit and the inclination of
the orbit to our line-of-sight interact to change the
apparent shape of the orbit. The orbits that are only
slightly inclined to our line of sight, and those that
have high eccentricities (i.e., are very egg-shaped)
both appear to be the same. The difference is that if
the orbit is really very eccentric, the center-of-mass
(barycenter) of the binary system will appear at one
focus of the ellipse. In orbits that are inclined to
our line-of-sight, the center-of-mass is not at one
of the foci of the observed ellipse.
The final part of this film showed
the giant star Sirius and its white dwarf companion.
The camera zooms in, showing giant Sirius as a disc,
but the white dwarf, as massive as our Sun, remains
a tiny dot. This portrays the tremendous density of
Sirius B, a white dwarf that is the size of Earth with
the mass of the Sun.
These films were an early attempt
to use computer-generated animation to bring the concepts
of astronomy to the student. Many computer simulation
programs in use today owe their existence indirectly
to these films.
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