The GROUSE project

Abstract

Context. Only recently it has become possible to measure the thermal emission from hot-Jupiters at near-Infrared wavelengths using ground-based telescopes, by secondary eclipse observations. This allows the planet flux to be probed around the peak of its spectral energy distribution, which is vital for the understanding of its energy budget. Aims. The aim of the reported work is to measure the eclipse depth of the planet HAT-P-1b at 2.2 μm. This planet is an interesting case, since the amount of stellar irradiation it receives falls in between that of the two best studied systems (HD 209458 and HD 189733), and it has been suggested to have a weak thermal inversion layer. Methods. We have used the LIRIS instrument on the William Herschel Telescope (WHT) to observe the secondary eclipse of HAT-P-1b in the K s -band, as part of our Ground-based secondary eclipse (GROUSE) project. The observations were done in staring mode, while significantly defocusing the telescope to avoid saturation on the K = 8.4 star. With an average cadence of 2.5 s, we collected 6520 frames during one night. Results. The eclipse is detected at the 4-σ level, the measured depth being 0.109 ± 0.025%. The uncertainties are dominated by residual systematic effects, as estimated from different reduction/analysis procedures. The measured depth corresponds to a brightness temperature of 2136 +150 −170 K. This brightness temperature is significantly higher than those derived from longer wavelengths, making it difficult to fit all available data points with a plausible atmospheric model. However, it may be that we underestimate the true uncertainties of our measurements, since it is notoriously difficult to assign precise statistical significance to a result when systematic effects are important.

Optical to near-infrared transit observations of super-Earth GJ 1214b: water-world or mini-Neptune?

“…4), but we find no significant correlations with the position on the detector or airmass, which we often see in other near-infrared measurements (e.g. de Mooij & Snellen 2009;de Mooij et al 2011). We therefore fitted the light curve with a second order polynomial simultaneously with the transit parameters.…”

GMRT search for 150 MHz radio emission from the transiting extrasolar planets HD 189733 b and HD 209458 b

“…This allows a reliable extraction of the contribution of the planet and its atmosphere to the received signal. This technique has made possible the detection of thermal infrared emission from an extensive sample of extrasolar planets using both Spitzer (e.g., Charbonneau et al 2005;Deming et al 2005;Stevenson et al 2010) and several ground based telescopes (e.g., Sing & López-Morales 2009;Croll et al 2010;Cáceres et al 2011;de Mooij et al 2011). Using Spitzer spectroscopy of planetary eclipses, infrared spectra of the atmosphere of HD 189733 b have revealed signatures of H 2 O absorption and possibly weather-like variations in the atmospheric conditions (Grillmair et al 2009;see Seager & Deming 2010, for a review on the Spitzer observations of planetary atmospheres).…”

Observed spectral energy distribution of the thermal emission from the dayside of WASP-46b

“…Photometric time series are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/567/A8 near-infrared (NIR) observations have emerged rapidly during the past three years (e.g., Croll et al 2011;Cáceres et al 2011;de Mooij et al 2011;Gillon et al 2012;Zhao et al 2012a,b;Deming et al 2012;Crossfield et al 2012;de Mooij et al 2013;Wang et al 2013;O'Rourke et al 2014;Chen et al 2014a,b), providing a good complement to the wavelength ranges covered by Spitzer and Hubble. The planetary energy budget can be constrained in the NIR where the planetary spectral energy distribution (SED) peaks.…”