Astronomers Are Excited About a Strange Flickering Star in Our Galaxy


Back in 2010, Zooniverse, the world's largest citizen science research platform, launched Planet Hunters at Yale University. The group of citizen scientists use data from NASA's Kepler Space Telescope to search for drops in brightness of distant stars, which could indicate potential new planets crossing in front of them. In 2011, they found something really unusual: a distant star with intriguingly bizarre behavior.

Now Yale astronomer Tabetha Boyajian—along with several citizen scientist co-authors—has published a paper in the Monthly Notices of the Royal Astronomical Society about the star, KIC 8462852, which has a flickering pattern unlike anything astronomers have seen before. The highly unusual data have even led some scientists to speculate that alien activity could be a factor. 

The data show several substantial dips in the brightness of the light from KIC 8462852, which suggests that there is a "tight formation" of objects circling the star. While the flux was relatively constant throughout the 4-year period observed during the survey, it was punctuated by a number of substantial dips, including one 15 percent dip around day 800 of the survey, and a whole sequence of dips—one of them reaching a depth of 22 percent—about day 1500. As Slate reports, even a dip caused by the transit of a Jupiter-sized planet is usually less than 1 percent. Moreover, this behavior would not be unusual if KIC 8462852 were a young star surrounded by dust and debris, but it isn't.

The report offers various possible explanations for this unusual activity, including "instrumental effects or data reduction artifacts" (issues with the equipment or glitches caused by cosmic rays) or the "aftermath of giant impact in planetary system" (colliding planets on unstable orbits), but Boyajian tells The Atlantic that nothing they came up with is bulletproof: "We were scratching our heads. For any idea that came up there was always something that would argue against it."

The findings were so "weird," Boyajian said, that they assumed something must've gone wrong during data collection. "We thought it might be bad data or movement on the spacecraft, but everything checked out," Boyajian told The Atlantic.

Others have more speculative ideas. Upon seeing Boyajian's data, Penn State astronomer Jason Wright and colleagues began working on a paper with an alternate interpretation, one that involves a "swarm of megastructures" built by aliens to harness energy from the Sun. Called Dyson Spheres, the structures appeared in science fiction novels as early as 1937. The term was later coined by noted physicist Freeman Dyson. While the structures themselves only exist in theory, scientists like Wright have not ruled out the possibility.

"When [Boyajian] showed me the data, I was fascinated by how crazy it looked," he told The Atlantic. "Aliens should always be the very last hypothesis you consider, but this looked like something you would expect an alien civilization to build." Sarah Kaplan of The Washington Post notes that the star is "about 1481 light-years away from Earth," which means that if these hypothetical aliens did build some structure, they did so a long time ago.

Wright has partnered with Boyajian and the director of the SETI Research Center at the University of California, Berkeley to develop a plan to further study KIC 8462852 using a radio dish to see if whatever is blocking the light "emits radio waves at frequencies associated with technological activity."  

How Often Is 'Once in a Blue Moon'? Let Neil deGrasse Tyson Explain

From “lit” to “I can’t even,” lots of colloquialisms make no sense. But not all confusing phrases stem from Millennial mouths. Take, for example, “once in a blue moon”—an expression you’ve likely heard uttered by teachers, parents, newscasters, and even scientists. This term is often used to describe a rare phenomenon—but why?

Even StarTalk Radio host Neil deGrasse Tyson doesn’t know for sure. “I have no idea why a blue moon is called a blue moon,” he tells Mashable. “There is nothing blue about it at all.”

A blue moon is the second full moon to appear in a single calendar month. Astronomy dictates that two full moons can technically occur in one month, so long as the first moon rises early in the month and the second appears around the 30th or 31st. This type of phenomenon occurs every couple years or so. So taken literally, “Once in a blue moon” must mean "every few years"—even if the term itself is often used to describe something that’s even more rare.

[h/t Mashable]

Neutron Star Collision Sheds Light on the Strange Matter That Weighs a Billion Tons Per Teaspoon
Two neutron stars collide.
Two neutron stars collide.

Neutron stars are among the many mysteries of the universe scientists are working to unravel. The celestial bodies are incredibly dense, and their dramatic deaths are one of the main sources of the universe’s gold. But beyond that, not much is known about neutron stars, not even their size or what they’re made of. A new stellar collision reported earlier this year may shed light on the physics of these unusual objects.

As Science News reports, the collision of two neutron stars—the remaining cores of massive stars that have collapsed—were observed via light from gravitational waves. When the two small stars crossed paths, they merged to create one large object. The new star collapsed shortly after it formed, but exactly how long it took to perish reveals keys details of its size and makeup.

One thing scientists know about neutron stars is that they’re really, really dense. When stars become too big to support their own mass, they collapse, compressing their electrons and protons together into neutrons. The resulting neutron star fits all that matter into a tight space—scientists estimate that one teaspoon of the stuff inside a neutron star would weigh a billion tons.

This type of matter is impossible to recreate and study on Earth, but scientists have come up with a few theories as to its specific properties. One is that neutron stars are soft and yielding like stellar Play-Doh. Another school of thought posits that the stars are rigid and equipped to stand up to extreme pressure.

According to simulations, a soft neutron star would take less time to collapse than a hard star because they’re smaller. During the recently recorded event, astronomers observed a brief flash of light between the neutron stars’ collision and collapse. This indicates that a new spinning star, held together by the speed of its rotation, existed for a few milliseconds rather than collapsing immediately and vanishing into a black hole. This supports the hard neutron star theory.

Armed with a clearer idea of the star’s composition, scientists can now put constraints on their size range. One group of researchers pegged the smallest possible size for a neutron star with 60 percent more mass than our sun at 13.3 miles across. At the other end of the spectrum, scientists are determining that the biggest neutron stars become smaller rather than larger. In the collision, a larger star would have survived hours or potentially days, supported by its own heft, before collapsing. Its short existence suggests it wasn’t so huge.

Astronomers now know more about neutron stars than ever before, but their mysterious nature is still far from being fully understood. The matter at their core, whether free-floating quarks or subatomic particles made from heavier quarks, could change all of the equations that have been written up to this point. Astronomers will continue to search the skies for clues that demystify the strange objects.

[h/t Science News]


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