14 DAY TRIAL // While analyzing a known Delta Scuti variable (dwarf Cepheid) star nearby, a group of experts from Spain noticed that the object features a large extrasolar planet in its orbit, that may influence its brightness. The interactions have not been observed until now.
The exoplanet, called HD 15082 b, or WASP-33b, was discovered back in 2010, by the SuperWASP planet-hunting project. It orbits very close to its star, and a year on it lasts precisely 1.22 days.
Astronomers in Spain were recently studying the parent star, called WASP-33 (or HD15082), when they began suspecting that the motions of the planet may have something to do with its brightness variation patterns.
WASP-33 is cataloged as a dwarf Cepheid because it exhibits variations in its luminosity due both to radial and non-radial pulsations of its surface. What experts did not know was that some of these pulsations may in fact be caused by the accompanying exoplanet, not the star itself.
Observations of the planetary system reveal that the large gas giant accompanying the star is likely a hot Jupiter-class planet, which may explain the short duration of its year.
The two objects, which are most likely tidally locked by the intensity of their gravitational and tidal interactions, can be seen about 378 light-years away, in the constellation of Andromeda, Daily Galaxy reports.
The star is a spectral type A celestial fireball that has 1.5 solar masses, say experts at the Universitat Autònoma de Barcelona (UAB) Institute of Space Sciences (IEEC-CSIC), who were in charge of the new investigation.
It is estimated that WASP-33b is only 0.02 astronomical units (AU) away from its parent stars. An AU is equal to the distance between the Earth and the Sun, or about 93 million miles. For comparison, Mercury is located 0.39 AU from the Sun, but is many times less massive than the exoplanet.
Due to this close proximity, the team suspects that the accompanying object may have a direct influence on the brightness variation patterns the star displays. A peculiar signal caught the attention of Spanish astronomers, who say that they plan to continue investigations.
Recently, a number of studies have proposed that hot Jupiter-class exoplanets – large objects orbiting near their parent stars – could have an influence on the brighting and dimming behavior of their parent. The correlation may hold especially true for variable stars.