Dual Dove
Thanks to NASA’s Kepler Space Telescope, an international team of astronomers joined forces and made quite the discovery.
They spotted a new eclipsing binary system, dubbed EPIC 216747137, which is also a post-common-envelope binary (PCEB) of the HW Virginis category.
The team’s work and more details are now available.
Here is what you need to know.
Surveying Eclipsing Binaries: What Should You Know
Eclipsing binaries (EBs) are some peculiar systems that display regular variations because one of the stars is traveling directly in front of its companion. HW Virginis stars are considered a type of EBs, comprising a hot subdwarf with an M-dwarf companion.
In the last few years, many new HW Virginis systems have been found from the light curves of the ATLAS and OGLE missions. According to astronomers, there will be even more discoveries thanks to NASA’s TESS (the Transiting Exoplanet Survey Satellite.
The team’s work
EPIC 216747137 was observed by NASA’s Kepler during its K2 mission. The team confirmed the HW Virginis origin of the cosmic body using the SAAO (the South African Astronomical Observatory), the NOT (the Nordic Optical Telescope), and the La Silla Observatory.
Furthermore, the astronomers discovered that EPIC 216747137 is a post-common-envelope eclipsing binary comprising an evolved and hot sub-luminous star of sdOB spectral type and a cold low-mass M-dwarf pal.
They also found that the system is approximately 2,900 light-years away and possesses an orbital period of only 3.87 hours. Such a thing triggers a powerful reflection effect from the other star.
Other Significant Details
The team also explained that EPIC 216747137 is only 505 light-years below the Galactic plane, meaning that the new system is part of our galaxy’s thin disc. And that’s a reason why the system is so intriguing.
The astronomers stated:
“[…] we conclude that the binary belongs to the thin disc population, which is also confirmed by its position in the Toomre diagram.”
