Kepler, the mysterious star and alien megastructure – Le Figaro

The Kepler space telescope NASA he really detected the light signal from an alien mega-structure around a distant star? Nothing is less sure, but this extravagant hypothesis is not ruled out by some professional astronomers. A possibility of extraterrestrial life reported by the US website The Atlantic immediately put in turmoil number of Internet users on social networks.

• What really observed the Kepler telescope?

The Kepler space telescope NASA is a great hunter of exoplanets, the planet does not belong to our solar system. Since its orbit, it has detected more than a thousand, recording very small variations in brightness when they pass in front of their star, a phenomenon called transit. Now, as the vast majority of planets are much smaller than their parent star, these transits, mini-eclipses, will diminish only marginally the emitted light of at most 1%. But in a very particular case, that of the star KIC 8462852, Kepler has made his light attenuation of up to 22%, which is huge. And the problem is that the brightness decreases are irregular and do not correspond at all to the passage of a planet around a star. It therefore can not be a planet, even giant. And KIC 8462852 is the only star on the 150,000 monitored by Kepler where such a phenomenon was observed.

• What are the possible explanations for this abnormal signal?

In a publication submitted to the journal Monthly Notices of the Royal Astronomical Society, and online pre-published on Arxiv server, Tabetha Boyajian, of the University of Berkeley (California), and some colleagues explore all possible ways to explain this anomaly. They first checked that it was not an instrument error. The additional observations with large ground-based telescopes have forced them to exclude the most mundane reasons: the star is too big and too old to be it remains of a large disk of material that would be currently give birth to planets eclipsing the light of the star. For want of better, astronomers are considering the passage of a huge string of comets could be caused by the gravitational disturbance of a small star, a red dwarf, near KIC 8462852. But this scenario does not explain all of the oddities signal recorded by Kepler.

• The extraterrestrial hypothesis is it serious?

The publication of Tabetha Boyajian and coauthors evokes no phenomenon alien . But the American astronomer ensures The Atlantic it proposes “alternative scenarios”, less “natural” than those mentioned in his article. One of his colleagues, Jason Wright, an astronomer at Penn State University expert on exoplanets and research of extraterrestrial civilization, even drafting a publication on the assumption of a mega-structure built in orbit around the star KIC 8462852 by a civilization with more developed technical capacities than ours.

These gigantic structures could be solar panels to collect the maximum of the energy emitted by the star. «Aliens should always be the last hypothesis to be considered, said Jason Wright at The Atlantic, but it sounds like what we imagine that an alien civilization might build.” A scenario that is not that of science fiction, as many theorists argue, as the Russian astronomer Nikolai Kardashev, a civilization that consumes more energy than can provide its home planet will then seek to use all the energy of the star around which she orbit, with a carpet of solar panels that surround the star, if that completely encompasses a structure called a Dyson sphere.

• Will it be possible to solve the mystery ?

Thanks to Institutde SETI (Search for Extra-terrestrial Intelligence), additional observations will be made with a large radio telescope to try to detect signals related to potential technological activity. As explained astronomer Phil Plait American on his blog, this assumption may well be very unlikely, the stakes are potentially huge, and that therefore it is worth a closer look.

However, forget any dream of extraterrestrial contact potential manufacturers. The star’s distance of 1500 light years, which means that what we are seeing today from the solar system has actually occurred … 1500 years ago.