The Cosmic Explorer
(600-2409) Projects Faxback Doc. # 33045
SUGGESTIONS FOR SCIENCE FAIR PROJECTS:
We don't know if you are a student or adult, but everyone can benefit from
the extraordinary pursuit of knowledge for its own sake. Here are a few
topics of investigation for the backyard Star Gazer or student in search
of a great Science Fair Project. The descriptions are skeletal, but you
can flesh out the details by contacting the Amateur Astronomers in your
area by writing to the Astronomical League (address on page 10.
1. Collecting and Identifying Micrometeoritic Ablation Spheroids:
Each day the Earth gets peppered by about 1,000,000,000 meteors. Most
are sand grain size and burn up in the atmosphere. You may see some
as "shooting stars". Tiny bits melt off due to friction as the
meteors rush through the air. These particles are called Ablation
Spheroids. They gradually settle to Earth and are found everywhere.
Many are magnetic. You can devise a collecting unit using a magnet or
a white catch basin to trap these particles. Examination should be
done at >50X magnifying power. You will be amazed by all of the
particulate contaminants found on your specimen slide-including auto
catalytic converter emission particles, tiny sand grains and dust;
pollen; factory emissions, and the Ablation Spheroids. Good sketching
technique, microphotography and statistical analysis will strengthen
your research.
2. Determination of Star Temperatures by Star Trail Photography: Stars
appear white to most people who casually glance at the sky. If you
spend as little as 1/2 hour looking at the stars on a dark night, you
will soon notice a great, but subtle, variety of colors. These range
from ruby reds to blue whites, with orange and yellow stars in
between. Color slide film with ISO speeds of 400-1200 are much more
sensitive than your eye to dim star colors. Use a 35mm single lens
reflex camera with time lapse capability, mounted on a tripod to do
this project. Focus the camera sharply on a bright star and open the
lens to the fastest f/number, be it 1.2, 1.4, 2.0, or whatever. A 50mm
lens works best-giving you a field of view of 20 degrees x 30 degrees.
Not only will the film capture color more easily. You will be astounded
at how many stars show up on the film. Start by using a 12 or 24
exposure roll of film to get your technique right.
A. With your equipment set up, point the camera toward the zenith on
a clear dark night and start your exposure by pressing the plunger
on the cable release.
B. Lock the shutter in the open position. Don't shake the camera.
C. After 25 seconds of exposure, carefully block the starlight from
entering the lens for 2 minutes. Don't stop the exposure!
D. After 2 minutes, the Earth's rotation will provide a 1/2 degree
space between the star images recorded in the first 25 second
exposure and the final exposure which comes next.
E. Carefully remove the obstruction you placed in front of the camera
lens without moving the camera in the least! Expose the film for
8 minutes then stop the exposure. You can repeat this for
different parts of the sky.
F. Use your Cosmic Explorer to identify the star fields and
constellations photographed before you make the exposure. Some
people get so excited, they neglect good record keeping, thinking
that memory will serve them later, but trust it doesn't work well.
Take good notes.
G. Your developed prints (glossy, not matte) can be examined by eye
or magnified. Identify the brightest stars using the Cosmic
Explorer. There are star charts and other information available
to check on the names and other data for dimmer stars. Use the
chart of 20 brightest stars for some of your first attempts.
H. Compare the color of the 2 degree star trail on the film to the
spectral type listed in the Star Data Tables. The K stars should
be yellow-orange, the M stars red; the G stars, yellow, etc. Your
intent is to estimate star temperatures by using color as the
indicator. Again, a clear project design will be very helpful.
This project makes an exciting display.
I. Your images will look like this:
a. 25 second exposure
b. 2 min space
c. color star trail 2 degree long
3. Spectral Photography of Stars:
This is a project which uses all the items needed in the above
exploration plus a medium dispersion transmission diffraction grating
available from many science education supply houses, like Edmund
Scientific in Barrington N.J. These plastic gratings are mounted in
2X2 slide holders and are quite inexpensive.
A. You will have to figure a way to mount the diffraction grating in
front of the camera so that the spectrum or color of dispersed
star light falls on the film along with the star. This is very
easy to do with a single lens reflex camera and it gives you an
opportunity to be technically creative.
B. Once you are satisfied that the diffraction grating is properly
positioned, take your unit outdoors on a dark clear night. Use
the stars listed in the 20 Brightest List as targets. Select a
range of spectral types.
C. Point the camera at the star and position it so that the star is
visible in edge of the field of view and the spectrum, which
should be visible in the middle of the field of view.
D. You want to set the optical system up so that as the Earth
rotates, the spectrum moves as a band across the film. It should
look like this:
a. Star Trail
b. Color spectrum band with dark vertical lines.
A little practice is needed but soon your spectral photos will be
works of scientific art.
E. Use reference information on stellar spectra to help identify the
nature of the dark absorption lines that should be visible in the
A-type and M-type stars.
F. This is a much more powerful technique than simple color
photography for identifying star spectra and temperature. You can
also experiment with planetary and lunar spectra-all of which are
reflected solar spectra of a G2V start another challenge is Nebular
and Cluster photography using your spectral set-up. This system
works well at the eyepiece end of a motor driven telescope. The
light gathering power of the telescope makes dimmer objects
manageable.
Your local amateur astronomy group; planetarium director;
university astronomy department; and public libraries are all
great sources of help, information and inspiration. With a little
perseverance, the rewards can be astronomical!
GOING FURTHER ON YOUR OWN:
We suggest that you contact the following for resources, information, and
inspiration in your pursuit of knowledge.
1. The Astronomical Workshop, Furman University, Greenville, SC, 29613,
USA: An excellent selection of annual sky calendar, plus books and
activities for adults and students.
2. Sky Publishing Corporation, PO Box 9111, Belmont, MA, 02178-9917.
Complete resource for publications, star atlas, charts, and observing
aids.
3. Observer's Handbook by The Royal Astronomical Society of Canada, a
comprehensive astronomy handbook published annually. Available from
Sky Publishing Corp.
4. The Astronomical League, Science Service Building, 1719 N. Street,
N.W. Washington, DC, 20030 Attn.: Executive Secretary. The League has
chapters of active amateur and professional members across the USA.
Send a self addressed stamped envelope to the League with a specific
request for selected free material and chapter locations.
(BR/EB 5/10/96)
Privacy Policy