Tag Archives: KIC 8462852

Cosmology

Tabby’s Star

KIC_8462852_in_IR_and_UV

Tabby’s Star, officially known by the cryptic notation KIC 8462852 is a very odd object. The star is around 1,500 light years from Earth, and has been puzzling astronomers with its strangely fluctuating brightness. Recent analysis shows that is even weirder than first thought, which has scientists baffled. Could the observations be caused by a storm of wildly orbiting comets? Or, much more compelling (for SciFi buffs), could it be an alien megastructure periodically shrouding the star?

From Space:

KIC 8462852 was observed by NASA’s Kepler mission and has become infamous for its bizarre and unprecedented transit signal that was flagged by citizen scientists. Now new research of precision Kepler observations has shown that the overall brightness of the star — unofficially named “Tabby’s Star” after astronomer Tabetha S. Boyajian who discovered the peculiar signal — has been decreasing, which poses a new and confusing problem for astronomers trying to understand what the heck is going on.

Kepler’s prime mission is to look for small worlds that pass in front of their parent stars causing a slight dimming of starlight. The “transit method” has been hugely successful and has confirmed well over 2,000 planets orbiting other stars in our galaxy.

But Tabby’s Star’s transit signal, otherwise known as a “light-curve”, stopped astronomers in their tracks. Something passed in front of it, dimming its starlight a whopping 20 percent and other jumbled transit signals revealed that something wasn’t quite right with this particular star. Then, in an interview with The Atlantic, Penn State University astronomer Jason Wright speculated that the signal could be indicative of an “alien megastructure” that’s in the process of being built. You can catch up on the controversy surrounding the anomalous signal in my recent Discovery News article “Closing In on ‘Alien Megastructure’ Clues.”

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So, in an effort to track down a rational explanation, Bradley Schaefer from Louisiana State University decided to study historical observations of KIC 8462852 in astronomical photographic plates from the past century to see if the star exhibited any bizarre fluctuations in brightness in the past. Sure enough, yes, the star is a bit of an oddball and has shown a long-term decreasing trend in brightness! Since the 19th Century, its brightness has decreased steadily by nearly 20 percent.

Now, astronomers Ben Montet (from Caltech) and Joshua Simon (from the Carnegie Institute) have released a paper to the arXiv preprint service detailing recent Kepler observations of KIC 8462852 since the space telescope was launched in 2009. Although the dataset for this time period is comparatively small, Monet and Simon found yet another surprise.

In the 4 years of Kepler’s primary mission, the star showed an unprecedented dimming of 3.5 percent. So not only did Kepler detect transient dips in brightness of up to 20 percent, there also seems to be a very definite downward trend in brightness throughout our observational history of the star.

No matter how you slice it, this is strange.

Read the entire story here.

Image: Tabby’s Star, KIC 8462852, in infrared (2MASS survey) and ultraviolet (GALEX). Courtesy: IPAC/NASA (Infrared), STScI/NASA (Ultraviolet). Public Domain.

BigBang

The Curious Case of the Strange Transit Signal

Something very strange is happening over at KIC 8462852. But, it may not be an alien intelligence.

KIC-8462852–Where-is-the-flux

NASA’s extrasolar, planet-hunting space telescope, found some odd changes in the luminosity of a star — KIC 8462852— located in the constellation of Cygnus, about 1,400 light-years from Earth. In a recent paper submitted to the Royal Astronomical Society, astronomers reported that:

“Over the duration of the Kepler mission, KIC 8462852 was observed to undergo irregularly shaped, aperiodic dips in flux down to below the 20 percent level.”

But despite several years of monitoring, astronomers have yet to come up with a feasible, natural explanation. And, this has conspiracy theorists, alien hunters and SciFi enthusiasts very excited. Could it be a massive alien structure shielding the star, or is there simpler and natural, but less amazing possibility? Occam’s razor could well prevail again, but I certainly hope not in this case.

From Wired:

Last week, astronomers—amateur and pro—got excited about some strange results from the Kepler Space Telescope, the NASA observatory tasked with searching for Earth-like planets. As those planets orbit their own distant suns, periodically blocking light from Kepler’s view, the telescope documents the flickers. But over the last several years, it has picked up a strange pattern of blips from one star in particular, KIC 8462852.

Light from that star dramatically plunges in irregular intervals—not the consistent pattern you’d expect from an orbiting planet. But what could possibly cause such a thing? Gotta be aliens, right? Clearly someone—something—has assembled a megastructure around its sun, like that hollow Celestial head in Guardians of the Galaxy. Or maybe it’s a solar array, collecting energy-giving radiation and preventing light from reaching NASA’s telescope.

This, of course, is almost certainly poppycock. When you’re searching the vast expanse of space, lots of things look like they could be signs of extraterrestrial life. Astronomical observers are constantly looking for tiny glimmers of information in the mess of noise that streams through space toward Earth, and often, things that at first look like signals end up being mirages. This has all happened before; it will all happen again. For example:

Pulsars

In 1967, astronomer Jocelyn Bell was monitoring signals from the Mullard Radio Astronomy Observatory, trying to analyze the behavior of quasars, energy-spewing regions surrounding supermassive black holes within distant galaxies. What she found, though, was a series of regular pulses, always from the same part of the sky, that she labeled LGM-1: Little Green Men. Soon, though, she found similar signals coming from another part of the sky, and realized that she wasn’t seeing messages from two different alien civilizations: It was radiation from a spinning, magnetized neutron star—the first measured pulsar.

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Sparks at Parkes

In 1998, astronomers at the 64-meter Parkes radio telescope in Australia started noticing mysterious radio signals called perytons—unexplained, millisecond-long bursts. The researchers there didn’t immediately cry alien, though; they could tell that the radio signals were terrestrial in origin, because they showed up across the entire spectrum monitored by the telescope. They didn’t know until this year, however, exactly where those emissions came from: a microwave oven on the observatory’s campus, which released a short, powerful radio signal when staffers opened its door in the middle of heating.

Read the entire story here.

Image: Flux time series for KIC 8462852 showing different portions of the 4-year Kepler observations. Courtesy: T. S. Boyajian et al, Planet Hunters X. KIC 8462852 – Where’s the flux?