Download March 2014 - Sudbury Astronomy Club

Club Website
Friday Mar 7, 2014
www.sudburyastronomyclub.com
Time 7:30 pm
Agenda:
1) Greetings
2) Wilf Meyer—The Planets
3) Dr. Bob Ulrichsen “Amateur Radio and the Jupiter/IO Connection”
4) Break
5) Robert Pothier—Occultation of Regulus
6) Darken the Dome
Luc Boulard receives the President’s Award for
2014 from Robert Pothier at the Feb. 7th AGM
Just shy of his 95th birthday, Jean Texereau ” France’s doyen of optical fabrication “ passed away on February 6, 2014. In recent years he’d been
living in the village of Seillans, in the department of Var.
For more than half a century Texereau made, refigured, or tested optics for large observatory telescopes. He also promoted amateur telescope making. But his enduring gift to “glass pushers” around the world was his book La Construction du Télescope d’Amateur, which first appeared in 1951.
An English edition, titled How To Make a Telescope, followed six years later.
In the book’s opening chapter, Texereau explained his concept of the standard telescope for beginners. This should be an 8-inch reflector, f/6 to f/8,
on an altazimuth mount that could be built without a machine shop. He set these limitations because he didn’t want to overwhelm enthusiasts in
their first attempt at a telescope. (However, as if to tantalize readers, he admitted that the book’s instructions would suffice for making mirrors up to
at least 20 inches in diameter!)
The author's well-worn copy of the first English paperback edition from the 1960s. The book had appeared in hardcover from Interscience Publishers in 1957.
Roger Sinnott
Compared to the American mirror-making books of the 1950s, Texereau’s was more sure-footed in its discussion of the diffraction effects in telescopes. The technique he described for evaluating a mirror’s figure was a significant advance, mathematically, over those used elsewhere.
An expanded second edition of the book reached the French market in 1961. It contained new chapters on making a Cassegrain reflector, an equatorial mounting, and a large optical window to cut down air turbulence within a reflector’s tube. The new material made the book greatly sought after,
and it soon went out of print. For a time in the 1980s, copies were selling for $1,000 on the second-hand book market.
Then in 1984, much to the excitement of a new generation of mirror makers, Willmann-Bell brought out the second English edition. It has remained
in print ever since. Texereau’s writing has an authoritative ring, and he was never one to hide his opinions. He would go out of his way to answer
letters from befuddled telescope makers, remembers Willmann-Bell’s Perry Remaklus. He may be the only professional optician ever to meld his
experiences with large optics into a book of practical advice for the amateur.
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Texereau’s first telescopes were homemade 10- and 20-inch reflectors. Then one day, in about 1946, the astronomer Gerard de Vaucouleurs introduced him to Andres Couder of Paris Observatory. Couder, who headed the optics laboratory there, promptly hired Texereau to be his right-hand
man.
At Paris Observatory, Texereau’s first project was to make the optics of a 24-inch Cassegrain reflector for Meudon Observatory. Many other duties
followed in the years to come, including work on the primary mirrors of the 76-inch reflector at Haute-Provence Observatory and the 42-inch reflector at Pic du Midi.
In 1964 Texereau was invited to McDonald Observatory in Texas to see what could be done about the soft star images of the 82-inch reflector. That
summer he performed 17 daily figuring steps on the 28-inch secondary mirror, and after each step he put the uncoated mirror back on the telescope
for star tests at night. Before Texereau’s arrival, the telescope’s overall wave front error had exceeded 1 wavelength of light. By the time he left,
this error had been reduced to just 1/8 wave.
Volunteer observers invited to time the March 20, 2014 Occultation of Regulus
Your help is requested to observe and time a rare and beautiful astronomical event! On March 20, 2014
shortly after 2:05AM EDT anyone standing outside under clear skies and looking to the west in a large
swath of New York State (ranging from Long Island and New York City all the way up to Oswego and Watertown) as well as portions of New Jersey, Connecticut, and Ontario (and on the island of Bermuda as
well) may see the bright star Regulus completely disappear from view for as long as 14 seconds as the
asteroid (163) Erigone passes in front of it. An event like this is called an occultation, and the web page
you are now reading will try to provide answers to some basic questions along with information on how
you can observe and contribute to the scientific study of this exciting event. The scientific community wants your help, and by reporting your observation (even an “I did not see the star disappear from my
location” report) you will be adding to the scientific knowledge about this asteroid.
Also, please follow and like the Facebook page for this event, www.facebook.com/Regulus2014 where
last-minute weather updates will be posted.
For access to the full page, click on http://occultations.org/Regulus2014/
For the past 3 years I have hosted family groups from Trinity United Church in Lively
for sky gazing sessions during the March break. The group really appreciated having
members of the Sudbury Astronomy Club answer their questions and share the fun.
We have chosen the Saturday March 8 or Sunday March 9, Saturday March 15 or
Sunday 16. The first one with good conditions is it! (One out of four has to be clear,
right?)
We will meet at Fielding Park. There is a trail near the end of the parking lot that proceeds nearer the river towards the back field. The area is fairly wide open and allows
for a group to be on level ground.
The first weekend is preferred, but Mother Nature will decide. The second weekend
holds a full moon.
Hopefully SAC members will consider helping with this outreach work. Mark your calendars, and give me a call if you want a reminder or verification should the weather be
questionable.
Linda Pulliah
705-671-8127
CURIOSITY PHOTOGRAPHS
EARTH: Last year when the Cassini
spacecraft photographed Earth through
the rings of Saturn, the whole world was
alerted to smile and wave. Last week,
Curiosity did the same thing with less
fanfare. Except for a few scientists, no
one knew the Mars rover would be taking this picture of the Earth-Moon system on Jan. 31st:
Northern Star Party Schedule for 2014
Thanks to Linda Pulliah for the details
Frozen Banana
May 1-4 Mew Lake, Algonquin (book NOW!)
New Moon in June
June 26-29 Mew Lake, Algonquin (book Jan 26)
Gateway
July 24-27 Martin River (reservations not req’d)
August Star Party
Aug 21-24 North Bay Astronomy Club
Location TDB, no reservations req’d
Half The Night
Aug 21-24 Halfway Lake (book Mar 21)
The Adventure
Sept 18-21 Mew Lake, Algonquin (book Apr 18)
Here is a list of websites that you may find interesting.
The list was provided by Kevin M. Chiasson from Timmins—thanks Kevin!
NASA
Google and Space
Space.com
We Choose the Moon
Exploremarsnow.org
Neave Planetarium
Sky-Map
Gigagalaxy Zoom
Galaxy Zoo (see article in this newsletter)
Google Sky
Spacedaily
Hubble Site
WHO IS STARGAZER STEVE!!
and What does he do?
Steve Dodson is a fellow amateur astronomer, who as a 2nd grader saved his allowance for a Telescope, and made his first 6-inch scope in grade 8.
As Stargazer Steve, he makes Telescopes that are designed to give more observing satisfaction to
beginners and experts alike, by focusing on design for performance.
In 1981, already an amateur astronomer with decades of observing experience, Steve built the largest mobile Telescope in Canada, and brought it to the Star Party that launched the Sudbury Astronomy Club.
In the 1990's Steve pioneered high-performance low-cost Reflecting Telescope Kits.
Steve has participated in the building of
over 4000 Telescopes, including solo
projects and activities with children, Astronomy Clubs and people of all ages.
The International Astronomical Union has
named Asteroid #13822
“Stevedodson”.
Over 2000 Stargazer Steve Telescopes
have been shipped throughout Canada,
the US, and around the World.
More Info at http://stargazer.isys.ca
http://neo.jpl.nasa.gov/orbits/ (Put
13822 in the blue box)