In nearly six years there are 247 b and 63 c orbits. Since 248:62 is 4:1, it can be seen why the observed ‘acceleration and deceleration’ of the planets might occur.
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Astronomers using the SuperWASP-North telescope on La Palma in the Canary Islands, Spain, and the SOPHIE spectrograph at the Observatoire de Haute-Provence, France, have discovered two giant exoplanets circling the G-type dwarf star WASP-148, reports Science News.
WASP-148 is a slowly rotating, inactive G-dwarf star 809 light-years away in the constellation of Hercules.
Also known as TYC 3083-295-1 and 2MASS J16563135+4418095, the star has the same mass and radius as the Sun.
WASP-148 hosts a planetary system composed of at least two giant planets, WASP-148b and c.
The inner planet, WASP-148b, is a hot Jupiter that transits its star with an orbital period of 8.8 days.
The alien world has a mass of about 0.3 times that of Jupiter and a radius about 0.72 times that of Jupiter.
“We found this planetary candidate with the SuperWASP photometric survey, then characterized it with the SOPHIE spectrograph,” explained Paris Institute of Astrophysics Professor Guillaume Hebrard and colleagues.
“Our radial velocity measurements subsequently revealed a second planet in the system, WASP-148c, with an orbital period of 34.5 days and a minimum mass of 0.4 times that of Jupiter.”
The orbits of WASP-148b and WASP-148c are eccentric and fall near the 4:1 mean-motion resonances.
“While WASP-148b orbits its star in nearly 9 days, WASP-148c takes four times longer,” the astronomers said.
“This ratio between their orbital periods implies that the WASP-148 system is close to resonance, meaning that there is enhanced gravitational interaction between the two planets.”
“While a single planet, uninfluenced by a second one, would move with a constant period, WASP-148b and WASP-148c undergo acceleration and deceleration that provides evidence of their interaction.”
Source: Science News.
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August 10, 2020 at 07:51AM