(Press-News.org) (Edmonton) A University of Alberta physicist brought together back-yard astronomers and professionals to confirm the mysterious behaviour of two stars more than 300 light years from Earth.
U of A astrophysics researcher Gregory Sivakoff was part of an international team that re-examined an established theory about periodic bursts of light coming from a binary star.
The two stars are called a binary star because they rotate around each other. The accepted theory on why the binary star, named SS Cygni, emits periodic bursts of light involves an interaction between the pair.
Sivakoff explains that one of the stars, a normal star that is a lower-mass cousin to our Sun, loses bits of its outer envelope to its neighbour, a white dwarf, which is as massive as our Sun, but squeezed down to the size of Earth.
"Gravity continuously draws material from the normal star's envelope, but it is only when the material rushes towards the white dwarf that we get an outburst of light," said Sivakoff. 'We see these outbursts happen about every 35 to 65 days."
The periodic light flash theory of SS Cygni was developed in the early 80s. Sivakoff says a key factor in the theory's calculations is the distance between Earth and SS Cygni.
In 1999 researchers with NASA's Hubble Telescope came up with a larger distance from Earth to the binary star. Sivakoff says that put the established theory into question.
To settle the distance issue Sivakoff and researchers from Australia, Britain, the Netherlands and the U.S. set out to re-measure the distance between Earth and the binary star.
Over the course of two-years Sivakoff worked with a world-wide network of 180 amateur astronomers who used their optical telescopes to watch the night skies and report whenever SS Cygni began one of its outbursts.
The researchers then called on ground based networks of radio telescopes to make the distance calculation. By the end of 2012, the researchers confirmed a smaller distance of about 370 light years from Earth to the binary star was correct.
"That was what we need to reconfirm the theory for periodic bursts of light from SS Cygni," said Sivakoff.
Sivakoff describes the research as a big win for Citizen Scientists.
"We would not have been able to vindicate the theory if dedicated amateur astronomers using their own equipment hadn't volunteered to help us," said Sivakoff.
Sivakoff is the second author of the research which was published May 24 in the journal Science.
### END
U Alberta teams with citizen researchers 370 light years from Earth
2013-05-24
ELSE PRESS RELEASES FROM THIS DATE:
A quantum simulator for magnetic materials
2013-05-24
Physicists understand perfectly well why a fridge magnet sticks to certain metallic surfaces. But there are more exotic forms of magnetism whose properties remain unclear, despite decades of intense research. An important step towards filling these gaps comes now from Tilman Esslinger and his group at the Department of Physics. The team has developed a new kind of device that uses laser beams and atoms to emulate magnetic materials. Their approach promises fundamental insights beyond what can be obtained with current theoretical and computational methods. Moreover, the ...
MRI-based measurement helps predict vascular disease in the brain
2013-05-24
OAK BROOK, Ill. (May 23, 2013) – Aortic arch pulse wave velocity, a measure of arterial stiffness, is a strong independent predictor of disease of the vessels that supply blood to the brain, according to a new study published in the June issue the journal Radiology.
"Pulse wave velocity from the aortic arch provides functional information about vessel compliance that may help determine a patient's risk for cerebrovascular disease down the road," said Kevin S. King, M.D., assistant professor of radiology at UT Southwestern Medical Center in Dallas.
Recent studies have ...
UCI study reveals new mechanism for estrogen suppression of liver lipid synthesis
2013-05-24
By discovering the new mechanism by which estrogen suppresses lipid synthesis in the liver, UC Irvine endocrinologists have revealed a potential new approach toward treating certain liver diseases.
With this finding, Dr. Ellis Levin and colleagues believe they are changing long-held views in the field. Study results appear in the May 21 issue of the journal Science Signaling.
"The dogma in the steroid receptor field for 50 years has been that only receptors located in the nucleus respond to steroid hormones by regulating genes that produce the developmental, functional ...
Understanding job committment may lead to better correctional employees
2013-05-24
DETROIT — Commitment to the job by correctional staff members cannot be bought but must be earned by an organization, a Wayne State University researcher believes.
A study by Eric Lambert, Ph.D., professor and chair of criminal justice in the College of Liberal Arts and Sciences, describes three types of commitment and the effects of three organizational concepts on them, based on a survey of 450 staff members at a maximum-security correctional institution in Michigan.
"Loyalty, Love, and Investments: The Impact of Job Outcomes on the Organizational Commitment of Correctional ...
Scientists offer first definitive proof of bacteria-feeding behavior in green algae
2013-05-24
A team of researchers has captured images of green alga consuming bacteria, offering a glimpse at how early organisms dating back more than 1 billion years may have acquired free-living photosynthetic cells. This acquisition is thought to have been a critical first step in the evolution of photosynthetic algae and land plants, which, in turn, contributed to the increase in oxygen levels in Earth's atmosphere and ocean and provided one of the conditions necessary for animal evolution.
In a paper that appears in the June 17 issue of Current Biology and is available online ...
Death rates decline for advanced heart failure patients, but outcomes are still not ideal
2013-05-24
UCLA researchers examining outcomes for advanced heart-failure patients over the past two decades have found that, coinciding with the increased availability and use of new therapies, overall mortality has decreased and sudden cardiac death, caused by the rapid onset of severe abnormal heart rhythms, has declined.
However, the team found that even today, with these significant improvements, one-third of patients don't survive more than three years after being diagnosed with advanced disease. Heart failure is increasingly common, affecting close to 6 million individuals ...
Syracuse University professor argues Earth's mantle affects long-term sea-level rise estimates
2013-05-24
From Virginia to Florida, there is a prehistoric shoreline that, in some parts, rests more than 280 feet above modern sea level. The shoreline was carved by waves more than 3 million years ago—possible evidence of a once higher sea level, triggered by ice-sheet melting. But new findings by a team of researchers, including Robert Moucha, assistant professor of Earth Sciences in Syracuse University's College of Arts and Sciences, reveal that the shoreline has been uplifted by more than 210 feet, meaning less ice melted than expected.
Equally compelling is the fact that ...
H7N9 animal model looks at transmission of H7N9 influenza virus
2013-05-24
Toronto – May 23, 2013 – Embargoed until 2:00 PM – An international team of scientists has proved that the H7N9 influenza virus is efficiently transmitted when animals are in close contact -- defined in the study as touching, coughing and the exchange of bodily fluids.
"This study was designed to give us clues about the transmission of H7N9 which has affected some humans in China," said David Kelvin, PhD, a senior scientist at the Toronto General Research Institute and Professor at the University of Toronto. "The animals used in the study had very mild clinical symptoms ...
University of Illinois biophysicists measure mechanism that determines fate of living cells
2013-05-24
Cells in the human body do not function in isolation. Living cells rely on communication with their environment—neighboring cells and the surrounding matrix—to activate a wide range of cellular functions, including reproduction of new cells, differentiation of stem cells into distinct cell types, cell adhesion, and migration of white blood cells to fight bodily infections. This cellular communication occurs on the molecular level and it is reciprocal: a cell receives cues from and also transmits function-activating cues to its neighbors.
The mechanics of this type of ...
UC Santa Barbara scientists discover cinnamon compounds' potential ability to prevent Alzheimer's
2013-05-24
Cinnamon: Can the red-brown spice with the unmistakable fragrance and variety of uses offer an important benefit? The common baking spice might hold the key to delaying the onset of –– or warding off –– the effects of Alzheimer's disease.
That is, according to Roshni George and Donald Graves, scientists at UC Santa Barbara. The results of their study, "Interaction of Cinnamaldehyde and Epicatechin with Tau: Implications of Beneficial Effects in Modulating Alzheimer's Disease Pathogenesis," appears in the online early edition of the Journal of Alzheimer's Disease, and ...