|
Large Alt-Az Telescope Forum
Presentations, Panel Discussion, and Walkabout
Friday, August 13, 1:00-3:30 PM,
Oregon Star Party 2010
Amateur telescope makers have broken the 1-meter telescope
barrier, and are now rapidly heading toward 1.5 and even 2.0
meter portable telescopes. OSP2010 will feature large alt-az
telescope forum consisting of a number of short PowerPoint
presentations, a panel discussion, and a special Mel Bartels
guided large scope walkabout. The key to large aperture
portable telescopes is, of course, affordable lightweight
mirrors, and advances are being made in meniscus, foam glass,
spun epoxy and other mirror technologies. Advances in other key
areas include direct drive motors and controllers (no gears,
belts, or friction rollers) and large telescope portability.
While some portable large alt-az telescopes will be used for
stunning visual observations—deep observing—others will be
non-imaging “photon funnels” used either signally or in arrays
for light bucket photometric or spectroscopic observations.
Oregon Star Party
2010 Science Workshop
The Oregon Star Party
(OSP) 2010 Science Workshop will feature quantitative
measurements of visual double stars with both equatorial and
Dobsonian telescopes equipped with Celestron Micro Guide
astrometric eyepieces, followed by analysis of the observations
and preparation of a paper for publication in the Journal of
Double Star Observations (JDSO). The star party workshop is
based on a one-weekend research seminar held at Pine Mountain
Observatory during the last two summers (Genet et al
2010). Russ Genet and Jo Johnson will introduce small telescope
science and visual double star observations in a general
interest one hour session on Thursday (2:00 PM). This will be
followed by a one-hour “how to” working session for workshop
participants led by Jo. Observations will be made that night,
the data will be analyzed on Friday, and a paper prepared for
publication. A general interest, one hour wrap-up/summary
PowerPoint presentation will be given on Saturday at 1:00 PM
describing how this pioneering workshop went and the scientific
results. To our knowledge, this will be the first ever science
workshop at a major star party with observational results
published in a scientific journal.
Double stars make
particularly excellent targets for both students and amateur
astronomers. The concepts, mathematics, and observations
involved are straightforward. To measure the angular separation,
the observer needs to measure the scale constant for the linear
scale of the eyepiece in arc seconds per division via a drift
calibration, count the number of divisions between the primary
and secondary stars, and multiply the number of divisions by
this scale constant. Position angle is measured relative to the
north celestial pole by aligning the stars along the linear
scale and allowing the primary star to drift from the center of
the eyepiece to an outer protractor. A small correction is
needed to calculate the position angle when the Celestron
Micro-Guide eyepiece is used (Teague 2004).
Most double star
researchers try to answer two questions: 1) is the double star
an optical, coincidental line-of-sight double or a
gravitationally bound binary system? 2) if the double star is a
binary, what are masses of the two components? To answer the
first question, astronomers look at the stars' two dimensional
proper motion vectors and trigonometric parallax (Arnold 2010).
To answer the second, astronomers use Isaac Newton's version of
Johannes Kepler's Third Law. Although answering these questions
usually requires observations spread over many years, each
individual observation adds to the final solution. The
individual observations, published in the in the Journal of
Double Star Observations, are additionally published in the
Washington Double Star Catalog maintained by the US Naval
Observatory, adding to some two centuries of visual double star
observations.
The equipment
required to make scientifically useful visual double star
observations is affordable, as only a telescope, astrometric
eyepiece, and simple stop watch are needed. Quality observations
have been made on telescopes as small as three inches (Grisham
2008). There are two common laser-etched astrometric eyepieces,
the Meade and Celestron, each of which cost around $150. We
prefer the Celestron eyepiece as its double, slightly spaced
apart “ruler” allows dimmer stars to be seen with precision
between the two rulers.
Finally, the
Journal of Double Star Observations offers swift, quality
publication which allows students and amateur astronomers to
experience both technical science writing and peer review. Many
experts in the field are willing to offer advice and collaborate
which helps neophytes complete their analysis and paper. The
research and science writing experience is directly applicable
to master’s theses, dissertations, and executive summaries.
Agenda
Thursday 12 August
Introduction to Small Telescope Science and Visual Double Star
Observations (main tent)
Everyone is invited to get a feel for what this is all about.
2:00-3:00 Overview: Small Telescopes &
Astronomical Research, Russ Genet & Jo Johnson.
3:00-4:00 Tutorial: How to Measure Visual Double Stars, Jo
Johnson
Working Sessions for Visual Double Star
Teams (only)
Thursday 12 August
5:00-7:00 Get acquainted dinner together,
final formation of teams.
7:00-9:00 Group tutorial observations demonstrating the
process by team leaders
9:00-Late Team observations of assigned double stars
Friday 13 August
Working Sessions for Visual Double Star Teams (only)
Late morning (to be arranged) Data analysis
Afternoon Complete data analysis, draft
paper(s)
Evening Group dinner, polish papers, discuss exit briefing
Saturday 14 August
Morning (to be arranged) Finalize exit PowerPoint briefings
Saturday 14 August
OSP2010 Science Workshop Results (main tent)
Everyone is invited to hear the research results from the teams
1:00-2:00 Research team reports
(introduced & MCed by Jo Johnson)
References
Arnold, Dave. 2010. Considering proper motion in the
analysis of visual double star observations. In
Small Telescopes and Astronomical Research, eds. R. Genet, J
Johnson, V. Wallen. Santa Margarita, CA:
Collins Foundation Press.
Genet, Russell, Berry, Richard, Johnson,
Jolyon, and Frey, Thomas. 2010. Pine Mountain Observatory summer
research workshop. In Small Telescopes and Astronomical
Research, eds. R. Genet, J. Johnson, V. Wallen. Santa
Margarita, CA: Collins Foundation Press.
Grisham, Darrell, Johnson, Jolyon, Genet,
Russell, and Arnold, David. 2008. Double star measurements with
a three inch Tasco telescope. Journal of Double Star
Observations, 4 (1), 10-13.
Teague, Tom. 2004. Simple techniques of
measurement. Observing and Measuring Visual Double Stars,
ed. Bob Argyle. London: Springer. |
