TY  - JOUR
A1  - Keles, Engin
A1  - Mallom, Matthias
A1  - von Essen, Carolina
A1  - Caroll, Thorsten A.
A1  - Alexoudi, Xanthippi
A1  - Pino, Lorenzo
A1  - Ilyin, Ilya
A1  - Poppenhäger, Katja
A1  - Kitzmann, Daniel
A1  - Nascimbeni, Valerino
A1  - Turner, Jake D.
A1  - Strassmeier, Klaus G.
T1  - The potassium absorption on HD189733b and HD209458b
JF  - Monthly Notices of the Royal Astronomical Society: Letters
N2  - In this work, we investigate the potassium excess absorption around 7699 Å of the exoplanets HD189733b and HD209458b. For this purpose, we used high-spectral resolution transit observations acquired with the 2 × 8.4 m Large Binocular Telescope (LBT) and the Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI). For a bandwidth of 0.8 Å, we present a detection >7σ with an absorption level of 0.18 per cent for HD189733b. Applying the same analysis to HD209458b, we can set 3σ upper limit of 0.09 per cent, even though we do not detect a K-excess absorption. The investigation suggests that the K feature is less present in the atmosphere of HD209458b than in the one of HD189733b. This comparison confirms previous claims that the atmospheres of these two planets must have fundamentally different properties.
Y1  - 2021
U6  - https://doi.org/10.1093/mnrasl/slz123
VL  - 489
IS  - 1
SP  - L37
EP  - L41
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Keles, Engin
A1  - Kitzmann, Daniel
A1  - Mallonn, Matthias
A1  - Alexoudi, Xanthippi
A1  - Fossati, Luca
A1  - Pino, Lorenzo
A1  - Seidel, Julia Victoria
A1  - Caroll, Thorsten A.
A1  - Steffen, M.
A1  - Ilyin, Ilya
A1  - Poppenhäger, Katja
A1  - Strassmeier, Klaus G.
A1  - von Essen, Carolina
A1  - Nascimbeni, Valerio
A1  - Turner, Jake D.
T1  - Probing the atmosphere of HD189733b with the Na i and K i lines
JF  - Monthly Notices of the Royal Astronomical Society
N2  - High spectral resolution transmission spectroscopy is a powerful tool to characterize exoplanet atmospheres. Especially for hot Jupiters, this technique is highly relevant, due to their high-altitude absorption, e.g. from resonant sodium (Na i) and potassium (K i) lines. We resolve the atmospheric K i absorption on HD189733b with the aim to compare the resolved K i line and previously obtained high-resolution Na i-D line observations with synthetic transmission spectra. The line profiles suggest atmospheric processes leading to a line broadening of the order of ∼10 km/s for the Na i-D lines and only a few km/s for the K i line. The investigation hints that either the atmosphere of HD189733b lacks a significant amount of K i or the alkali lines probe different atmospheric regions with different temperature, which could explain the differences we see in the resolved absorption lines.
Y1  - 2020
U6  - https://doi.org/10.1093/mnras/staa2435
VL  - 498
IS  - 1
SP  - 1033
PB  - Oxford Univ. Press
CY  - Oxford
ER  -