By: Tammy Plotner
Have you ever wondered if what you observe in your backyard telescope could make a difference to astronomical studies? Before you put your equipment away and resolve that what you see isn't important, think again.
Just recently, a University of Alberta physicist teamed with professional researchers and amateur astronomers just like you to verify the enigmatic behavior of a pair of stars located about 300 light years away.
Cataloged as SS Cygni, this pair of stars is known as a binary system, because they orbit each other. Physics researcher, Gregory Sivakoff, and his international team became interested in this particular system because they wanted to validate a theory about periodic bursts of light emitted by the duo: SS Cygni may produce these bursts as part of an interaction between them.
One of the stars is quite ordinary - a low-mass relatively similar to the Sun which expels part of its outer envelope to be collected by its companion. The companion is a white dwarf star — as massive as the Sun, but compressed down to the size of Earth.
"Gravity continuously draws material from the normal star's envelope, but it is only when the material rushes toward the white dwarf that we get an outburst of light," said Sivakoff. "We see these outbursts happen about every 35 to 65 days."
Artist's conception of a white dwarf and a companion star. The white dwarf, the bright white object within the disk, sucks matter from its more sedate companion star. The star eventually emits a huge flash of light. (Image: NASA)
Sivakoff explains that the periodic light-flash theory of SS Cygni was first postulated over three decades ago. At the time, it was based on calculations of the distance between us and the binary system.
However, in 1999, researchers employing the Hubble Space Telescope delivered a different set of numbers. Apparently the distance from Earth to SS Cygni was a bit further than previously thought, and this put the light-flash theory into question.
Which set of distances was correct? For Sivakoff, it was time to go back to the drawing board. To help resolve the issue, he engaged researchers from Australia, Britain, the Netherlands and the United States to re-measure the distance between us and this mysterious binary star. For over two years, the team also included a network of 180 amateur astronomers, armed with their personal optical telescopes. These "citizen scientists" kept watch on the night skies and reported each time SS Cygni went into outburst.
Thanks to their quick time reports, the professionals were then able to alert ground-based radio telescopes to compute the distance. The information poured in, and by the end of 2012 the researchers confirmed that the shorter value of 370 light years was correct.
"That was what we need to reconfirm the theory for periodic bursts of light from SS Cygni," said Sivakoff.
Was this a triumph for backyard astronomers and their telescopes? You bet. Many of the telescopes used were of the Newtonian design and the light bursts which originated from SS Cygni left the star at roughly the time that Sir Isaac Newton was born!
It's a big win for citizen science, and Sivakoff gives credit where credit is due.
"We would not have been able to vindicate the theory if dedicated amateur astronomers using their own equipment hadn't volunteered to help us," he said.
So remember the next time you observe: it might be nothing more than just a flash on the Moon, but what you see can make a difference!
Have you ever spotted SS Cygni? For tips on observing Binary Stars click HERE.
Tammy Plotner is a professional astronomy author, President Emeritus of Warren Rupp Observatory and retired Astronomical League Executive Secretary. She's received a vast number of astronomy achievement and observing awards, including the Great Lakes Astronomy Achievement Award, RG Wright Service Award and the first woman astronomer to achieve Comet Hunter's Gold Status.