Long-time Slashdot reader RockDoctor writes: Remember the screaming and welcoming of our Dyson-Sphere-Dwelling 1500 LY distant Overlords that accompanied the news that star KIC 8462852 was irregularly dimming on both short and longer timescales? A second star with a similar light curve has been discovered and reported on ARXIV. With the euphonious names “EPIC 204278916” and “2MASS J16020757-2257467”, the star is a young M1 (red) star, traveling as part of a group of stars which haven’t had time to disperse from their place of formation. The age is estimated at 5 — 11 million years. Analysis of 70+ days of data from the K2 mission epoch shows a rotation of 3.6 days, but a period of 25 days near the start of the observation epoch showed dips in intensity of up to 60% lasting for up to about a day each. Details are in the Arxiv paper linked to above, particularly figures 1 and 4.
If confirmed, this discovery changes the situation with interpreting the so-called “Tabby’s Star”. Firstly with a second object in the class, the odds of it representing a class of naturally occurring objects compared to a unique, unusual object is greatly increased. Secondly, the different celestial mechanical situations around the different stars allows a better estimate of plausible formation mechanisms. One potentially important point is that clumps of debris that could produce these dimmings seem to be quite large. “It is also important to note that the resulting size for the transiting and occulting clump would be quite large at with the clump being in the order of 1.5 times the radius of the Sun. Sadly, this appears to be a new class of “dirty young planetary system.” no alien Overlords, no screaming in the streets. Just business-like astronomy.
Read more of this story at Slashdot.