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Tag Archives: Alex Filippenko

From a UC Berkeley press release, June 2, 2016:

Astronomers have obtained the most precise measurement yet of how fast the universe is expanding at the present time, and it doesn’t agree with predictions based on other data and our current understanding of the physics of the cosmos. The discrepancy – the universe is now expanding 9 percent faster than expected – means either that measurements of the cosmic microwave background radiation are wrong, or that some unknown physical phenomenon is speeding up the expansion of space, the astronomers say.

“If you really believe our number – and we have shed blood, sweat and tears to get our measurement right and to accurately understand the uncertainties – then it leads to the conclusion that there is a problem with predictions based on measurements of the cosmic microwave background radiation, the leftover glow from the Big Bang,” said The Cosmos author Alex Filippenko, a co-author of a paper announcing the discovery. “Maybe the universe is tricking us, or our understanding of the universe isn’t complete.”

The cause could be the existence of another, unknown particle – perhaps an often-hypothesized fourth flavor of neutrino – or that the influence of dark energy (which accelerates the expansion of the universe) has increased over the 13.8 billion year history of the universe. Or perhaps Einstein’s general theory of relativity, the basis for the Standard Model, is slightly wrong.

“This surprising finding may be an important clue to understanding those mysterious parts of the universe that make up 95 percent of everything and don’t emit light, such as dark energy, dark matter and dark radiation,” said Nobel Laureate Adam Riess, the leader of the study. Riess is a former UC Berkeley post-doctoral fellow who worked with Filippenko. The results, using data from the Hubble Space Telescope and the Keck I telescope in Hawaii, will appear in an upcoming issue of The Astrophysical Journal.

Links: UC Berkeley press release with more details of the measurements; Hubble press release; the ApJ paper;

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From an article by Kelly Beatty in Sky & Telescope, November 30, 2014:

A year ago, the situation looked bleak for historic Lick Observatory, the venerable 125-year-old mountaintop facility that overlooks California’s Silicon Valley. Faced with huge commitments to support its investment in Hawaii’s Keck Telescopes and to help fund the billion-dollar Thirty Meter Telescope, officials at the University of California (which owns and operates Lick) decided there just wasn’t enough money to go around. So they decreed that Lick should be divested from the university and find its own funding, with a “glide path” toward self-sufficiency to begin within two years and be completed by 2018.

Credit: Debra and Peter Ceravolo

Credit: Debra and Peter Ceravolo

Needless to say, the September 2013 announcement rocked the astronomical community in a way that few of the area’s earthquakes ever could. Although “closure” was never actually stipulated, it loomed as the most likely outcome for a venerable institution that held a premier role in U.S. astronomy a century ago. Prominent members of the astronomical community cried out in protest. Cosmologist (and author of The Cosmos) Alex Filippenko (UC Berkeley) led a “Save Lick Observatory” campaign. California congressmen petitioned the university’s president to reconsider the decision. The area’s amateur astronomers mobilized for a fight. Apparently, all that high-profile resistance – coupled with some belt-tightening – has spared Lick from being cast adrift.

While the observatory’s short-term prospects are now relatively secure, proponents are taking steps to ensure its long-term survival. A Lick Observatory Council, involving Filippenko, other scientists, and private citizens, has started private fundraising efforts and to expand the observatory’s outreach and education programs.

Links: the full article in Sky & Telescope; Lick Observatory public information.

Author Alex Filippenko’s recent talk “Discovering Our Celestial Connections: New data on Exploding Stars, Exoplanets, and Black Holes from UC’s Lick Observatory”, recorded at LinkedIn headquarters, is available to view below or here (approx. 1 hr 27 minutes).

A bright supernova discovered only six weeks ago in a nearby galaxy is provoking new questions about the exploding stars that scientists use as their main yardstick for measuring the Universe. (See this earlier post about SN 2014J.)

SN2014J-350

Credit: W. Zheng and A. Filippenko (UC Berkeley)

When The Cosmos author Alex Filippenko’s research team at UC Berkeley looked for the supernova in data collected by the Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory, they discovered that the robotic telescope had actually taken a photo of it 37 hours after it appeared, unnoticed, on January 14.

Combining this observation with another chance observation by a Japanese amateur astronomer, Filippenko’s team was able to calculate that SN 2014J had unusual characteristics – it brightened faster than expected for a Type Ia supernova and, even more intriguing, it exhibited the same unexpected, rapid brightening as another supernova that KAIT discovered and imaged last year (SN 2013dy).

Alex Filippenko reports: “Now, two of the three most recent and best-observed Type Ia supernovae are weird, giving us new clues to how stars explode. This may be teaching us something general about Type Ia supernovae that theorists need to understand. Maybe what we think of as ‘normal’ behavior for these supernovae is actually unusual, and this weird behavior is the new normal.”

A paper describing the SN 2014J observations was posted online this week by The Astrophysical Journal Letters and will appear in the March 1 print issue.

Links: UC Berkeley press release (including further background on Type Ia supernovae); the research paper in ApJL.

Stream or listen to the podcast of the most recent Planetary Radio show from The Planetary Society to hear authors Jay M. Pasachoff and Alex Filippenko talk about “The Cosmos”, Fourth Edition, among other topics.

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Links: Planetary Radio show, January 21, 2014.