Auburn Astronomical Society
In this Issue
This monthís meeting will be on Friday,
1, at 8:00PM in room
215 of the Aerospace Engineering Building. Riders from the Montgomery
area are welcome to meet at the home
of Russell Whigham, 518
Seminole Dr., and carpool over to Auburn. Plan to be ready to
leave for Auburn at 7:00PM.
Our star party this month will be the better
of the two nights of Friday/Saturday, April 8/9, at Cliff
A. Gayle Planetarium, Saturday, April 16, 2005
The following people have volunteered to help
with our Astronomy Day activities:
Jim McLaughlin, Meade 8-inch LX200
Rhon and Joyce Jenkins 18-inch StarMaster Dobsonian
Allen Screws, 8-inch Dobsonian
Alan & Susie Cook, 10-inch LX-50 SCT
Chuck Lewis, 10-inch LX-200 GPS SCT
Mike Holley ETX-70 refractor
William Baugh, 12-inch home made Dobsonian; 120mm
Robert Rock, Meade ETX 90 Maksutov
Eddie Kirkland, 16-inch f/4.5 Dobsonian
Russell Whigham, 11-inch f/10 SCT
Ray Kunert, 10-inch LX-200 GPS SCT
Tom and Julie McGowan 8-inch Homemade Reflector
John Tatarchuk 18-inch Obsession Dobsonian
Several of our regular volunteers for this
annual event are conspicuous by their absence on this list. We still
need your help. Let
us know if you can try to be there. We need help at the
AAS information table, someone to coordinate satellite passage announcements
to the visitors, and someone to facilitate use of the AAS PST solar telescope.
If you can help with the telescope clinic, we need your help too.
Note that weíre beginning earlier that usual this year so that visitors
can view the Sun with our new solar scopes. If you have a traditional
white light solar filter, be sure to bring it as well. Drop-inís
are welcome if at the last minute you see that you can come, but you may
not have a name tag or sandwich if you donít let us know in advance.
Remember to wear your AAS shirt.
If this will be your first Astronomy Day with
us at the planetarium, you can get an idea of what to expect from the Web
pages linked at http://www.auburnastro.org/gayle.htm
Primary targets of the telescopes will be the
first quarter Moon, Saturn, and eventually, low in the east, Jupiter.
Do you have too many telescopes cluttering up
your garage? Rick has also encouraged us to bring our surplus hardware
to sell. This is a great time to make it available to a would be
We will continue to give the free yearís AAS membership
as a door prize. This has never resulted in an actual new membership,
but weíll continue the tradition. A few years ago Gail Smitherman
suggested that we also donate books and other astronomical gifts.
I recently found a book at Barnes & Nobles on the clearance table to
bring. If you are so inclined, just bring your donation to the event
that day, and weíll be sure the society gets a plug from Rick.
Below is the agenda shamelessly lifted from Rickís
Astronomy Day: April
8th Annual Astronomy Day Event
3:00 PM - Solar viewing
Public Viewing of the Sun through Solar Scopes
provided by the Planetarium and Auburn Astronomical Society.
5:00 PM - Telescope Clinic
Members from the Auburn Astronomical Society
will host a telescope clinic to answer questions about different types
of telescopes. If you have a telescope that you need assistance with,
you are encouraged to bring it to this event.
6:00 PM - Guest Speaker
Dr. David T. King Jr.
Dr. King's presentation will be on the Wetumpka
6:45 PM -- Remarks from Auburn Astronomical Society
President (Dr. Rhon Jenkins)
7:00 PM - "Tour of the Night Sky"
The Spitz STP projector in the auditorium
will be set to display the stars as seen from Montgomery Alabama on April
16th, 2005. A brief tour of the night sky will be conducted to point
out the constellations visible .
7:30 PM - Challenger/Columbia Tribute
7:45 PM - Door Prize selection
8:00 PM - Telescopic celestial viewing
Astronomical Society (AAS)
has agreed to support this event by once again bringing out telescopes
for the public to view the wonders of the night sky.
From: "Rick Evans" <rlevans(AT)troyst.edu>
Subject: Re: AAS A-Day Volunteers
I really appreciate all the folks who stepped up to the plate (it's spring,
I thought I could use a baseball metaphor) each year.
updated the Web page, before I had read this email, so right now I have
on their the AAS membership, but I can always change it. Our new address
since the name change for the University is:
have been in contact with Dr. King and he is going to do a briefing on
the crater again this year. He said that it was modified, so it will
be a little different. Mr. Dorsey will also have time to say a few
words on the status of the Wetumpka Meteor Crater Commission.
also allotted some time for Rhon to say a few words if he would like.
I intend to mix the Astronomy 101 with the tour of the night sky we typically
do each year.
plan is to once again work with Subway and see if we can have food and
drinks for your folks and mine.
me know if there is anything else we need to do, or that you can think
of between now and then.
again for all your support and help with this endeavor (threw in a shuttle
name just for kicks).
A. Gayle Planetarium
April 1, AAS Meeting (No Foolin')
April 3, Begin Daylight Saving Time
April 6-9, 2005, Mid-South
April 8 Partial
Solar Eclipse Begin,4:35; Max 5:10; End 6:00PM CDT
April 8/9, AAS Star Party, Cliff
April 16, Astronomy Day, W.A.
May 6-May 8, 2005, Georgia
Sky View, Indian Springs GA
May 6, AAS Meeting
May 14th, Combined AAS Star Party / Forest Preserve
Light From A Distant Planet
From: "Michael Strauss" <email@example.com>
of the most dramatic breakthroughs in astronomy in the past decade has
been the discovery of planets around other stars. In every case,
the presence of the planet is inferred by the motion they impart on their
parent star; there is a periodic Doppler shift in the spectrum of the star
as it moves in reflex to its planet. But now, astronomers have used
the Spitzer Space Telescope to detect photons from the planet directly.
are over 160 planets that have been discovered to date. A small fraction
of them have orbits oriented such that they pass periodically in front
of their parent star, as seen by us. When this happens, they block
a small fraction (typically 1%) of the light of the star while they pass
in front. The question some clever astronomers considered is: can
we see the effect when the planet is hidden by the star?
they had taken Astro 203, so they could reason as follows: from the
Doppler shift data, I know the period of the orbit. Knowing the mass
of the parent star (given its spectrum, the temperature can be inferred,
and knowing it is a main sequence star, the mass follows), I can therefore
determine the radius of the orbit from Keplerís Third Law. Given
the radius of the orbit, and the temperature of the star, I can infer the
temperature of the planet. From the fraction by which the light diminishes
during the planetary transit, I know the planetís radius. So if I
know the planetís radius and its temperature, I can get its luminosity.
they went through these considerations for a particular transiting planet
known as TrES-1 (that stands for ĎTrans-Atlantic Exoplanet Surveyí, in
case it wasnít obvious), they concluded that the planet in this case it
roughly the size of Jupiter, in a 3-day orbit at 0.04 Astronomical Units
(i.e., very close to its parent star!); it is therefore quite hot, with
a predicted surface temperature of 1000 K. Such a planet has a black-body
spectrum that peaks at about 3 microns, i.e., in the infrared part of the
spectrum. The parent star, with a surface temperature of perhaps
4000 K, is far from its peak in the infrared, so the contrast between planet
and star should be maximum at that wavelength. So they observed the
planet-star system with the Spitzer Space Telescope, with its sensitivity
to infrared radiation. The telescope certainly doesnít have the resolving
power to distinguish the planet from the star, but it when the planet disappears
behind the star, the total light should decrease by just a smidgen.
is exactly the effect seen. David Charbonneau and colleagues took
a picture of the star with the Spitzer Space Telescope every 13 seconds
for six hours, centered on the predicted period of 2.5 hours when the planet
should be behind the star. They saw a diminution of light exactly
when expected. The effect is tiny. Even though the planet is
at its peak of the blackbody spectrum, and the star is far from its peak,
taking the light of the planet away decreases the total brightness at 4
microns by only 0.06%! But this was just the amount expected, given
the numbers above.
cool! But what does it really tell us? Well, this is the first
time that photons from a planet have been unambiguously been seen directly
(as opposed simply to measuring the effect of the planet on its parent
star). Astronomers are eager to learn about the physical properties
of these planets, starting with such basics as their mass, size, temperature,
and albedo (i.e., reflectivity). These measurements confirm estimates
of their size and temperature, and show that the albedo is actually quite
similar to that of Jupiter. The evidence that these objects look
something like Jupiter gets stronger every day.
a completely different subject, check out one of the most astonishing astronomical
images Iíve seen in a long time: http://photojournal.jpl.nasa.gov/jpeg/PIA06606.jpg
was taken by the Cassini spacecraft orbiting Saturn; it was taken from
an orientation with the rings exactly edge-on. Notice the moons Dione
and Enceladus in the ring plane. Most striking is the shadow cast
by the rings on the Northern hemisphere of the planet. Breathtaking!
you want to see more pictures from Cassini, look at:
above article was sent to me from a cousin who lives near Princeton and
took Dr. Straussí continuing education astronomy course. So, there
are advantages to living in light-pollution. ;-) Thanks, Ed.]
Hope to see everyone at the meeting and star