Possible detection of phase changes from the non-transiting planet HD 46375b by CoRoT

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Possible detection of phase changes from the non-transiting planet HD 46375b by CoRoT

Post by Borislav on 14th October 2010, 3:08 pm

Strange, but it missed this important publication.

http://adsabs.harvard.edu/abs/2010A%26A...518L.153G

Context. The present work deals with the detection of phase changes in an exoplanetary system. HD 46375 is a solar analog known to host a non-transiting Saturn-mass exoplanet with a 3.0236 day period. It was observed by the CoRoT satellite for 34 days during the fall of 2008.
Aims: We attempt to identify at optical wavelengths, the changing phases of the planet as it orbits its star. We then try to improve the star model by means of a seismic analysis of the same light curve and the use of ground-based spectropolarimetric observations.
Methods: The data analysis relies on the Fourier spectrum and the folding of the time series.
Results: We find evidence of a sinusoidal signal compatible in terms of both amplitude and phase with light reflected by the planet. Its relative amplitude is Δ Fp/Fstar = [13.0, 26.8] ppm, implying an albedo A = [0.16, 0.33] or a dayside visible brightness temperature Tb ≃ [1880, 2030] K by assuming a radius R = 1.1 RJup and an inclination i = 45. Its orbital phase differs from that of the radial-velocity signal by at most 2 σ_RV. However, the tiny planetary signal is strongly blended by another signal, which we attribute to a telluric signal with a 1 day period. We show that this signal is suppressed, but not eliminated, when using the time series for HD 46179 from the same CoRoT run as a reference.
Conclusions: This detection of reflected light from a non-transiting planet should be confirmable with a longer CoRoT observation of the same field. In any case, it demonstrates that non-transiting planets can be characterized using ultra-precise photometric lightcurves with present-day observations by CoRoT and Kepler. The combined detection of solar-type oscillations on the same targets (Gaulme et al. 2010a) highlights the overlap between exoplanetary science and asteroseismology and shows the high potential of a mission such as Plato.

There is a complete article.

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Re: Possible detection of phase changes from the non-transiting planet HD 46375b by CoRoT

Post by Borislav on 14th October 2010, 3:19 pm

Probably this is the first detection of the phase curve for non-transiting planets in the optical range.

Until then, I only saw a similar article
http://arxiv.org/abs/0802.2732
But there is more vague.

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Re: Possible detection of phase changes from the non-transiting planet HD 46375b by CoRoT

Post by Sirius_Alpha on 14th October 2010, 4:30 pm

I recall CoRoT getting an optical phase curve of CoRoT-1 b some time ago.

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Re: Possible detection of phase changes from the non-transiting planet HD 46375b by CoRoT

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