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News From LI Science Center
Summer Apprenticeships
Teens are invited to apply to join the
staff of the Long Island Science Center as volunteer interns
during July and August 2008.
"Work behind the scenes, design
and build exhibits and assist staff with
programs."
For more info and an application, call
208-8000.
Sunday Science and Summer Science
Through the end of June, the Long Island
Science Center offers a Sunday Science program where families
can enjoy hands-on science activities with special themes
that change weekly.
Families can make math and science a
part of their summer at the Long Island Science Center
every Wednesday through Sunday from 11:00am to 4:00pm
with special themes changing weekly.
The
Long Island Science Center is located at 11 West Main
Street, Riverhead.
Brookhaven Lab Open to Public on Summer
Sundays
The U.S. Department of Energy's Brookhaven
National Laboratory will again open its doors to the public
this summer, every Sunday from July 20 through August
17.
The Laboratory will feature a different
tour on each of five Sundays. Both adults and children
can enjoy a variety of entertaining activities, including
the Whiz Bang Science Show and the Brain Teasers exhibit
each week.
Summer Sundays are offered free of charge,
and no reservations are needed. Visitors may arrive any
time between 10 a.m. and 3 p.m. The Whiz Bang Science
Show will be staged at 10:30 a.m., noon, 1:30 p.m. and
3 p.m. each Sunday. All visitors age 16 and over must
bring a photo ID.
The full Summer Sundays schedule follows:
July 20 National Synchrotron
Light Source
See the brightest light on Long Island and one of
the most intense sources of light in the world. Find out
how synchrotron light is used to look into all kinds of
materials, from moon rocks to computer chips.
July 27 Science Learning Center
Play with science, no matter what your age. Have fun
testing your hands-on science skills. Enjoy a science
magician's tricks.
August 3 National Weather Service
Come to the weather forecasting center for the entire
New York metropolitan area. Track storms, big or small.
Learn about hurricane preparedness. Witness a 3:30 p.m.
weather-balloon launch.
August 10 Center for Functional
Nanomaterials
Visit a new center where studies of the ultra-small may
lead to ultra-big discoveries in many areas, from energy
to electronics. See the high-tech tools used to explore
the nanoscale. This tour is appropriate for adults and
children over 10 years old.
August 17 Relativistic Heavy
Ion Collider
Enter the underground tunnel that holds twin accelerators.
Learn how gold ions are smashed together to recreate the
temperature and energy density of the early universe.
This tour is appropriate for adults and children over
10 years old.
The Laboratory is located 1.5 miles north
of Long Island Expressway Exit 68. For more information,
call 631 344-2651, or visit the Brookhaven Lab website:
www.bnl.gov.
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Double Deception
by David van Popering
July 2008
The giant twin suns of Tatooine slowly disappear behind
a distant dune range. Luke stands watching them for a
few moments, then reluctantly enters the doomed entrance
to the homestead...

This scene from Star Wars showed
those of us here on Earth the strange yet somewhat familiar
world of Luke Skywalker. A world filled with household
robots and talking androids, fantastic ships, and in this
scene, a world with two suns. Much of the technology remains
in the realm of science fiction. The binary suns, as strange
as they seem, are really out there.
A binary star is actually a pair of stars
that orbits around a common center of gravity. They are,
in a sense, connected.
There are so many multiple stars systems
that it has allowed astronomers to determine the masses
of stars and provided a wealth of information on the density,
atmosphere, and evolution of stars. They are also extremely
useful as distance indicators, allowing astronomers to
measure the distance to the clusters and galaxies. The
study of binary stars has helped change our understanding
of the scale of the Universe.
Many stars, like our Sun, were formed
in open clusters which eventually drifted apart, leaving
each star alone. Many more are born in twos, threes, and
fours and remain that way for a very long time.
As many as there are, no one imagined
such a thing existed, even when they looked right at them.
Early astronomers, after years of scanning and studying
the night sky with the earliest telescopes, thought binary
or multiple stars were a chance alignment of stars and
nothing more. The discovery that they are actually close,
orbiting stars was made in the late 1700s by William Herschel
and his wife Caroline also served as his full-time assistant.
They catalogued so many that they knew there couldn't
be that many "chance alignments." After observing
them for decades and noting their motions, they determined
these aligned stars were multiple star systems.
How many binary stars are there? It's
difficult to be precise, but of the stars nearest to the
Sun, about half are known to be in multiple systems.
Real
or Illusion?
Binary stars can be of two fundamental
types: Visual Binaries and Optical Doubles.
Visual Binaries are those you can see.
Sometimes you don't even need a telescope. Usually they
do appear as a single point of light, but using a telescope,
you can "split" them so you can see the separate
stars.
Optical Doubles are stars that appear
to lie close together, but in fact are not at all. They
only appear to us from our earthly observation to be close
together. One of the stars in the pair is actually behind
the first star and very far away. The stars of an optical
double are not gravitationally bound.
Hint: Can't remember a visual
from an optical? I think of the phrase "optical illusion."
Optical Binaries are illusions and not real binary pairs.
There is another type which is important,
called the spectroscopic binary. The spectroscopic binaries
are those which are very close together and cannot be
"split" with an optical telescope. The individual
stars are each identified by their own light. All the
chemical elements are revealed, like a unique fingerprint,
through a spectroscope (a machine which analyzes light).
Each star is made up of a combination of elements in differing
amounts; one might have more carbon or helium than another.
Through analyzing the light, astrophysicists can determine
the light coming from individual stars, which to our eyes
seem to shine as one.
Since it is the Visual Binaries which
you can enjoy from your own dark back yard, or better
yet, from Custer, here are a couple to start you off with,
and we're more than happy to help you find them from the
Custer Institute some dark Saturday evening.
What
We Thought We Knew
To start with, many of the stars you
already know are really binaries and in some cases, multiple
star systems. The first one might come as a bit of a surprise:
Polaris, the North Star, is a triple star system. That's
right, the North Star is really three stars! One of its
stellar companions is clearly visible with a telescope,
but the other hugs Polaris so tightly that it has never
been directly observed until 2006 with the Hubble Space
Telescope. If you come to Custer, I can show you Polaris
and one of it's companions.

Alberio is one of the summertime showpieces. This beautiful
double is one of my favorite objects to share with our
Custer visitors. (Alberio and its companion are found
in the head of Cygnus the swan who flies along the milky
white backdrop of our galaxy. "The Northern Cross"
is the more easily found asterism within Cygnus, and if
thats what you can find, then look to the foot of the
cross to find Alberio.)
Alberio is one of the most beautiful
double stars in the sky and probably the finest for small
telescopes. The primary member, Alberio A, is a golden
yellow. Alberio B, the smaller of the two is a hot blue-white
star and they complete an orbit about once every 600 years.
These two stars are just over 400 billion miles apart.
At least 55 solar systems could be lined-up edge-to-edge,
across the space that separates these stars! But wait,
there's more! Spectroscopic analysis has revealed that
the yellow star is also a very close double itself--a
triple star system!
Here is how Alberio will appear to you
when see from Custer:

There is more going on down at Custer
than looking for double stars. Check the Custer
web site for the latest updates and additions! Remember,
Custer is open to the public every Saturday evening from
dusk to midnight and you can call 765-2626 for more information.
Clear Skies,
David van Popering
Coming Up
Saturday, July 5, 2008.
Concert: Homegrown String Band
Suggested donation $15. An exceptional evening of
bluegrass music and dance.
Saturday, July 12, 2008.
Open Mic Night
Free.
Afternoon StarLab shows are being
planned as well as other summer programs, so be sure to
check the website for the latest info.
Download the current sky map!
http://skymaps.com/downloads.html
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Links
Custer
Observatory
Long
Island Science Center
Brookhaven
National Laboratory
Article
Archives
"Winter
Nights,"
January 2008
"Our
Universe in Motion,"
February 2008
"R
U A Star Hopper?"
March 2008
"Springtime
Globular Clusters"
April 2008
"Galaxies!"
May 2008
"M"
Is For Messier, Marvelous & Must-See!
June 2008
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