beyond the orbit of Neptune was discovered more than hundred new asteroids. Perhaps this achievement will help to find the mysterious “planet X”.
the Project Dark Energy Survey (DES), that is “Review [to study] dark energy”, started in 2013 and was recently completed. For six years, astronomers observed area of 5000 square degrees (about one-eighth of the entire sky). For this purpose we used the four-meter Blanco telescope at CTIO Observatory located in the Chilean Andes.
During this time, astronomers have collected data on more than 300 million distant galaxies. The main purpose of this work, as the name suggests, was the study of dark energy — the mysterious substance that causes the Universe to expand with acceleration.
However, such extensive observational material can (and should) be used by scientists not only for its intended purpose. Therefore, astronomers have been resourceful and wring from it all possible information. For example, researchers have used it to study supernovae and mapping dark matter.
in addition, the sensitivity of the telescope and wide field-of-view was easy to search for TRANS-Neptunian objects (TNO) — the small celestial bodies orbiting the Sun beyond the orbit of Neptune.
you could call Them asteroids, although the professionals usually use this term to refer to bodies that are closer to the sun. Unlike “real” asteroid, probably composed largely of ice, not stone. The largest known TNO astronomers — Pluto, Haumea, Makemake and Eris — are dwarf planets.
Today, there are about 3000 TRANS-Neptunian objects. New work increases this number to 139 of the heavenly bodies.
the Location of TRANS-Neptunian objects, open the project DES. Translation News.Science.Illustration Of Pedro Bernardinelli.
Kait is not difficult to guess the search for such objects — it laborious. To distinguish Solar system object from the background stars, it is necessary to lock its movement across the sky. Tools that are specifically aimed at search it, take pictures every hour or two. It is easy to understand, whether the object shifted. In the framework of DES, the data is updated less frequently. Therefore, the authors had to develop a package of algorithms designed to search for celestial Wanderers against a stationary and calm of the distant stars.
Using data for the first four years, the authors identified the photographs of seven billion pixels, whose brightness exceeded the background by some threshold. Then they deleted objects remain in the same place for several nights (stars, galaxies, and so on). There’s 22 million potential TNO.
the researchers Then compared the images to see the dots that did not disappear the next night to nowhere, and only slightly moved. Finding the trail of this “traveler” a few photographs, scientists have calculated its trajectory and checked whether it appeared in the following images where I had to.
In the end, the authors found 316 TNO. Of these, 177 were already known to mankind (including 106 was discovered in the DES data because of previous research). 139 well become the completely new “catch.”
Found in the DES data objects are located at distances from 30 to 90 astronomical units from the Sun (one and.e. equal to the distance between the sun and our planet). For comparison, Pluto is 40 and.e. from the Sun and the most distant known object in the Solar system — 120 and.e.
Now, astronomers conducted a re-analysis of data with a lower detection threshold, hoping to discover even fainter objects.
the authors Also note that the developed algorithm can be useful for finding it on other telescopes, observational program which was not designed for this purpose.
needless to say that “the census the population of the” edge of the Solar system is interesting in itself. But the project DES carefully recorded spectrum of the observed objects. This means that in the future it will be possible to determine not only the size of the “newcomers”, but also their chemical composition.
There is, however, another reason for such studies. “Conduct.Science” (nauka.vesti.ru) wrote extensively on the hypothesis that beyond the orbit of Neptune there is a mysterious “planet X”. Careful observation of the orbits of many TRANS-Neptunian bodies will help astronomers to understand whether this is an intriguing hypothesis.
read More about the study, says the scientific article, published in the Astrophysical Journal Supplement Series.