Amateurs Help Astronomers Unravel A Propeller Star
AAVSO Press Release
25 August 2005
Amateur astronomers are being asked to help a constellation of
observatories unravel the mysteries of a puzzling binary star
system.
On August 30-August 31, 2005 two space-based and four professional
ground-based observatories are scheduled to observe the cataclysmic
variable star AE Aqr. Each of the observatories covers a different
wavelength of light and amateur astronomers have been asked to help
cover the visible-light portion.
"This observing campaign will take place over nearly a full day,
and since no single ground-based observatory can observe AE Aqr for
that long due to Earth's rotation, amateur astronomers can make a
unique and invaluable contribution to this campaign," said Dr.
Christopher Mauche of Lawrence Livermore National Laboratory, the
principal investigator of the project.
Because they are spaced all across the globe, amateur astronomers
can observe this star and other celestial objects unhindered by
nightfall or weather.
The Chandra and GALEX space telescopes will be working with the
HESS, MAGIC, VLT, and VLA ground-based telescopes. Combined, they
will provide coverage of AE Aqr from high-energy gamma-rays to
low-energy radio waves. Such simultaneous multiwavelength coverage
is required to provide the clearest picture of the locations, mass
motions, energetics, and inter-relationships of the various emission
regions in the star.
AE Aqr is an intermediate polar, a type of cataclysmic variable
star. It actually consists of two stars - a red dwarf and rapidly
spinning magnetic white dwarf. Material drawn off the red dwarf
falls toward the white dwarf, but instead of landing on the white
dwarf surface, it is flung out of the system by the white dwarf's
rapidly spinning magnetic field. This mechanism, which is uncommon
but not unique to AE Aqr, is referred to as a magnetic propeller.
"Amateurs astronomers have been observing AE Aqr since 1944.
Since then, they have recorded over 28,815 measurements of the star,
most of them made with just a telescope and their eyes. This type of
historical data is immensely valuable in studying variable stars and
only amateurs can provide it," Dr. Arne Henden, Director of the
American Association of Variable Star Observers (AAVSO), said.
Amateur astronomers are being asked to observe AE Aqr every night
possible until September 3. Those with CCD cameras on their
telescopes are requested to make scientific brightness measurements,
known as photometry, of the system as well. For information on how
to measure the brightness of AE Aqr and submit results to
professionals, visit the AAVSO web site at
http://www.aavso.org/alertnotice .
The AAVSO is the world's preeminent professional-amateur
astronomical association. Specializing in the study of variable
stars, the AAVSO's International Database has over 11 million
observations of variable stars dating back over 100 years. Founded
in 1911 as part of the Harvard College Observatory, the AAVSO became
independent in 1954 and currently has over 3,000 members and
observers in over 40 countries.
Contact:
Dr. Christopher Mauche
Lawrence Livermore National Laboratory
(925) 422-7017
mauche@cygnus.llnl.gov
Dr. Arne Henden
Director, American Association of Variable Star Observers
(888) 802-STAR (7827) or (617) 642-3883
arne@aavso.org
AAVSO
Clinton B. Ford Astronomical Data & Research Center
25 Birch Street Cambridge, MA 02138
http://www.aavso.org