Shporer, Avi and O'Rourke, Joseph G. and Knutson, Heather A. and Szabó, Gyula M. and Zhao, Ming and Burrows, Adam and Fortney, Jonathan and Agol, Eric and Cowan, Nicolas B. and Desert, Jean-Michel and Howard, Andrew W. and Isaacson, Howard and Lewis, Nikole K. and Showman, Adam P. and Todorov, Kamen O. (2014) ATMOSPHERIC CHARACTERIZATION OF THE HOT JUPITER KEPLER-13Ab. The Astrophysical Journal, 788 (1). p. 92. ISSN 0004-637X

[img] Text
Restricted to Registered users only

Download (3MB) | Request a copy


Kepler-13Ab (= KOI-13.01) is a unique transiting hot Jupiter. It is one of very few known short-period planets orbiting a hot A-type star, making it one of the hottest planets currently known. The availability of Kepler data allows us to measure the planet's occultation (secondary eclipse) and phase curve in the optical, which we combine with occultations observed by warm Spitzer at 4.5 μm and 3.6 μm and a ground-based occultation observation in the Ks band (2.1 μm). We derive a day-side hemisphere temperature of 2750 ± 160 K as the effective temperature of a black body showing the same occultation depths. Comparing the occultation depths with one-dimensional planetary atmosphere models suggests the presence of an atmospheric temperature inversion. Our analysis shows evidence for a relatively high geometric albedo, A g = 0.33^{+0.04}_{-0.06}. While measured with a simplistic method, a high A g is supported also by the fact that the one-dimensional atmosphere models underestimate the occultation depth in the optical. We use stellar spectra to determine the dilution, in the four wide bands where occultation was measured, due to the visual stellar binary companion 1.''15 ± 0.''05 away. The revised stellar parameters measured using these spectra are combined with other measurements, leading to revised planetary mass and radius estimates of Mp = 4.94-8.09 M J and Rp = 1.406 ± 0.038 R J. Finally, we measure a Kepler midoccultation time that is 34.0 ± 6.9 s earlier than expected based on the midtransit time and the delay due to light-travel time and discuss possible scenarios.

Item Type: Article
Subjects: Q Science / természettudomány > QB Astronomy, Astrophysics / csillagászat, asztrofizika
Depositing User: Dr Szabó M. Gyula
Date Deposited: 18 Sep 2014 13:43
Last Modified: 18 Sep 2014 13:43

Actions (login required)

Edit Item Edit Item