"The dips found by Kepler are real. Something seems to be transiting in front of this star and we still have no idea what it is." confirms German astronomer Michael Hippke. Even if aliens are not involved, Tabby's star remains "the most mysterious star in the universe" as Yale astronomer Tabetha Boyajian described it in a TED talk.
Previously, we announced the investigation was focusing on a breach in the cryogenic helium system of the second stage liquid oxygen tank. The root cause of the breach has not yet been confirmed, but attention has continued to narrow to one of the three composite overwrapped pressure vessels (COPVs) inside the LOX tank. Through extensive testing in Texas, SpaceX has shown that it can re-create a COPV failure entirely through helium loading conditions. These conditions are mainly affected by the temperature and pressure of the helium being loaded.
SpaceX’s efforts are now focused on two areas – finding the exact root cause, and developing improved helium loading conditions that allow SpaceX to reliably load Falcon 9. With the advanced state of the investigation, we also plan to resume stage testing in Texas in the coming days, while continuing to focus on completion of the investigation.
The report suggests that they are starting to pin down the very specific temperature and pressure conditions during loading of the helium tank that cause the problem, which also suggests they will soon also be able to adjust their procedures to avoid those conditions. This also suggests that they repeated assurances that they will be able to fly before the end of the year are not unreasonable….”
But while most such dimming by transiting planets is brief, regular and blocks just 1 or 2 percent of the light of the star, Tabby’s star dims for days at a time, by as much as 22 percent, and at irregular intervals.
While Boyajian speculated in her 2015 paper that the irregular dimming might be explained by a swarm of comets breaking up as it approached the star, subsequent observations show the star, which is located about 1,500 light-years from Earth in the constellation Cygnus, is far more irregular than a comet swarm would produce. In fact, it seems to have been dimming at a steady rate for the past century.
Speculation eventually arose that the dimming was caused by a Dyson structure: a massive orbiting array of solar collectors that physicist Freeman Dyson once proposed would be a natural thing for a civilization to build as it needed more and more energy to power itself. Theoretically, such a structure could completely surround the star – what he termed a Dyson sphere – and capture nearly all the star’s energy….”
If intelligent aliens actually do live around Tabby's star, astronomers are determined to find them.
The Breakthrough Listen initiative, which will spend $100 million over the next 10 years to hunt for signals possibly produced by alien civilizations, is set to begin studying Tabby's star with the 330-foot-wide (100 meters) Green Bank Telescope in West Virginia, project team members announced Tuesday (Oct. 25).