In late 2015, the scientific community was fueled up by the Kepler Space Telescope's detection of several mysterious objects that orbited around the giant star KIC 8462852.
Nicknamed Tabby's Star, KIC 8462852 is quite peculiar as it glows and dims into strange, fluctuating light patterns -- something that has baffled scientists. The star is 1,480 light-years away from our planet.
Scientists from Louisiana State University said that the intensity of the star dimmed by 20 percent in the course of the last 100 years, which is unprecedented coming from an F-type main sequence star.
Brief Timeline Of Theories
A myriad of theories as to why this happened came flooding in. Some astronomers postulated that the mysterious objects surrounding the star were an advanced alien megastructure.
"Aliens should always be the very last hypothesis you consider," Jason Wright, astronomer at Pennsylvania State University, said in October. But Wright believed the objects appeared like something an alien civilization could build.
However, other experts disagreed. Scientists from Iowa University and Massachusetts Institute of Technology (MIT) proposed the possibility that this alien megastructure is actually just a swarm of comets.
It was plausible that comet fragments that pass swiftly at an arduous orbit form huge clouds of debris that dim the star, they said. When the clouds of debris move, the original brightness of the star comes back and leaves no trace of infrared light.
But then again, another study in January ruled out the comet swarm theory. Scientists re-investigated KIC 8462852 by looking at data from Harvard University's database of photographic plates of the sky from 1890 to 1989.
To cut a long story short, researchers led by Bradley E. Schaefer concluded that the comet-swarm theory does not match current observations. Schaefer said it would take about 648,000 comets - each 124 miles wide - to pass by Tabby's Star to block the brilliance and then return it. This was impossible.
There's More!
And just when you thought that was the end of it, scientists are now claiming that there are issues with some of the data used in the Louisiana State University study. They say the observations were actually tainted by the inconsistent use of telescopes on Earth.
In this new report featured in the Astrophysical Journal, researchers from Lehigh University and Vanderbilt University, with the help of a novice astronomer and NASA postdoc fellow, further assessed the details of the LSU study.
Their conclusion? There was no credible and sufficient data to support the hypothesis that KIC 8462852 darkened to such an extent over the last 100 years.
Their re-investigation was prompted by the source of the LSU data itself known as DASCH, or Digital Access to a Sky @ Harvard. This was the same source of data Schaefer used during his re-investigation.
The problem was, given the age or date of the photographic glass plates, it was not impossible that scientists used different telescopes to capture images of the sky from 1885 to 1993. It was a 108-year-long project.
Keivan Stassun, co-author of the new study, says whenever scientists make research based on archives that combine data from different sources, there are surely limits in accuracy and preciseness. These limits should be taken into account.
Stassun and his colleagues examined the variations in the brightness of comparable stars found in the DASCH records. Most of these stars saw a similar drop in brightness in the 1960s, Stassun says.
"That indicates the drops were caused by changes in the instrumentation not by changes in the stars' brightness," he added.
Then what now?
This may seem like a discouraging finding, but science is meant to weed out the inaccurate ideas to finally make room for the real answer. The silver lining is this: the LSU study may probably be crossed out from the list of possible explanations.
In the meantime, the mystery behind KIC 8462852 has yet to be solved.
