| Nov 10, 2021 |
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(Nanowerk News) A brand new approach developed partially by University of Hawaiʻi astronomer Nader Haghighipour has allowed scientists to shortly detect a transiting planet with two suns.
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Termed circumbinary planets, these objects orbit round a pair of stars. For years, these planets had been merely the topic of science fiction, like Tatooine in Star Wars. However, because of NASA’s profitable planet-hunting Kepler and Transiting Exoplanet Survey Satellite (TESS) missions, a crew of astronomers, together with Haghighipour, have discovered 14 such our bodies up to now.
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| Artist’s rendition of the Kepler-47 circumbinary planet system with its three planets. (Image: NASA/JPL-Caltech/T. Pyle)
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Kepler and TESS detect planets through the transit technique, the place astronomers measure the tiny dimming of a star as a planet passes in entrance of its host star, blocking among the starlight. Usually, astronomers have to see at the least three of those transits to pin down the planet’s orbit. This turns into difficult when there are two host stars.
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“Detecting circumbinary planets is much more complicated than finding planets orbiting single stars. When a planet orbits a double-star system, transits of the same star don’t occur at consistent intervals,” defined Haghighipour. “The planet might transit one star, and then transit the other, before transiting the first star again, and so on.”
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Adding to the problem, the orbital intervals of circumbinary planets are at all times for much longer than the orbital interval of the binary star. That means, in an effort to observe three transits, scientists want to watch the binary for a very long time. While that was not an issue with the Kepler space telescope (this telescope noticed just one area of the sky for 3.5 years), it makes it difficult to make use of the TESS telescope to detect circumbinary planets, as a result of TESS observes one portion (or sector) of the sky for under 27 days earlier than pointing someplace else, making it inconceivable to watch three transits of a planet with TESS.
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In 2020, Haghighipour and his crew discovered a method round this limitation. In an article revealed in The Astronomical Journal, they described a novel approach that might allow them to detect circumbinary planets utilizing TESS, so long as the planet transited each of its host stars throughout the 27-day observing window.
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Now, that very same crew of astronomers has really discovered the primary such circumbinary planet in TESS knowledge, demonstrating that their approach works. The goal binary is understood by its catalog designation, TIC 172900988, and was noticed in a single sector by TESS, the place its lightcurve confirmed indicators of two transits, one throughout every star, separated by simply 5 days – throughout the identical conjunction.
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“This planet’s orbit takes almost 200 days – with the traditional transit method, we would have needed to wait over a year to detect two additional transits. Our new technique reduced that time to just five days, showing that despite its short window of observation, TESS can be used to detect circumbinary planets. The new planet is the proof of the validity, applicability and success of our invented technique,” mentioned Haghighipour, founding father of the TESS Circumbinary Planet Working Group. “This discovery demonstrates that our new technique works and will be able to find many more planets.”
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The discovery of the primary TESS circumbinary planet utilizing this new approach seems within the The Astronomical Journal (“TIC 172900988: A Transiting Circumbinary Planet Detected in One Sector of TESS Data”). Haghighipour is a co-author with lead authors Veselin B. Kostov (NASA Goddard Space Flight Center), SETI Institute, and GSFC Sellers Exoplanet Environments Collaboration.
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