List of Posters

Author(s): Engin Keles

Abstract:

Jupiter-type exoplanets orbiting their host star in close orbits, the so-called hot and ultra-hot Jupiters, have been studied in detail due to their enhanced atmospheric signature. Due to their tidally locked status, the temperature difference between the day- and night sides triggers atmospheric winds which can lead to various fingerprints in the observations. Spatially resolved absorption lines during transit such as sodium (Na) could be a good tracer for such winds. Different works resolved the Na- absorption lines on exoplanets which show different line widths. Assuming that this is due to zonal jet streams, this work shows the effect of such winds on synthetic absorption lines for transiting Jupiter-type planets. There is a tendency that the broadening values decrease for planets with higher equilibrium temperatures. This could be explained by atmospheric drag induced by the ionization of alkali lines which slow down the jet streams or by the decrease of the effective radiative timescale for hotter planets, favoring high wind velocities on cooler rather than hotter Jupiter- type planets for the investigated target sample. The line profile deformation resolved especially during the ingress and egress could be used to prove this assumption and if true, to determine super-rotational wind patterns on exoplanets.

References:

Keles 2021, MNRAS 502, 1456–1468

Author(s): Sara Khalafinejad, Elias Hühn, Karan MolaverdiKhani, Lisa Nortmann, Andreas Quirrenbach, et. al

Abstract:

With the large number of transiting exoplanets discovered, we are now entering the era of comparative study of the exoplanetary atmospheric compositions and properties. We aim to homogeneously investigate the Na and He absorption features in ten giant exoplanets observed using CARMENES. So far, we performed narrow-band transmission spectroscopy on six of the targets. The absorption feature of these exoplanets show a decreasing trend by the increase
exoplanetary equilibrium temperature. No such trend is observed when their absorption feature is compared with surface gravity of exoplanets. To achieve a more robust result we still have to complete the analysis of all of our targets.

Author(s): Rengel Miriam, Adamczewski Jakob

Abstract:

The study of planetary atmospheres is crucial for understanding the origin, evolution, and processes that shape celestial bodies like planets, moons and comets. The interpretation of planetary spectra requires a detailed understanding of radiative transfer (RT) and its application through computational codes. With the advancement of observations, atmospheric modelling, and inference techniques, diverse RT and retrieval codes in planetary science have been proliferated. However, the selection of the most suitable code for a given problem can be challenging. To address this, we present a comprehensive mini-overview of the different RT and retrieval codes currently developed or available in the field of planetary atmospheres. This study serves as a valuable resource for the planetary science community by providing a clear and accessible list of codes, and offers a useful reference for researchers and practitioners in their selection and application of RT and retrieval codes for planetary atmospheric studies.

References:

Rengel, M. and Adamczewski , J. Submitted to Frontiers in Astronomy and Space Sciences, Planetary Science

Author(s): Hendrik Schmerling, Elisa Goffo, Sascha Grziwa, Martin Pätzold, Davide Gandolfi, Carina M. Person, Coel Hellier, John Livingston

Abstract:

The Transiting Exoplanet Survey Satellite (TESS) has opened up a world of new planet candidates through its transit observations. However, confirming the existence of these candidates as actual planets requires additional data, such as radial velocity (RV) observations of the potential host star. Measuring the orbital and planetary parameters is crucial to better understand planetary formation and evolution. In this study, we utilized RV measurements of the late K dwarf CD-31 1415 to determine the mass and density of the planet associated with TESS Object of Interest (TOI) 2427, as well as search for any other companions to the host star. Our results confirm the detection of the transiting planet TOI 2427b as a rocky planet with a period of 1.31 days and reveal the existence of an additional, non-transiting companion to CD-31 1415 with a period of 5.17. Combining these different methods revealed a rocky, super-Earth sized inner planet with a semi major axis less than 10 times the radius of the host star and a second slightly more massive planet (TOI 2427c) that orbits the star with a four times resonance to TOI2427b.

References:

Grziwa, S. & Pätzold, M. 2016, arXiv preprint arXiv:1607.08417
J. P. Gardener, John C. Mather, 2006, Space Science Reviews, 123, 750
Kurucz, R. L. 2013, ATLAS12: Opacity sampling model atmosphere program,
Astrophysics Source Code Library
Persson, C. M., Fridlund, M., Barragán, O., et al. 2018, A&A, 618, A33
Scargle, J. D. 1982, The Astrophysical Journal, 263, 835
Stassun, K. G., Oelkers, R. J., Pepper, J., et al. 2018, The Astronomical Journal,
156, 102

Author(s): Dane Späth, Sabine Reffert

Abstract:

The two most successful exoplanet detection techniques, the Transit- and Radial Velocity (RV) methods, inherently bias the unveiled planet population towards close-in, short-period planets. While these close-in detections are incredibly useful to study the composition and atmospheres of exoplanets, they paint an incomplete picture of the planet population as a whole. Recently, the old 72cm Waltz Telescope (built in 1905) located at Landessternwarte Heidelberg has been equipped with a high-resolution (R ~ 55000), cross-dispersed Echelle spectrograph dedicated to continue the Lick survey, an RV monitoring campaign of 373 bright G and K giant stars started in 1999. Using the iodine cell technique the instrument is designed to achieve an RV precision of three to five m/s. Special focus will be put on candidates identified in the Lick survey showing long-term trends. With a baseline of already 24 years and long-term prospects, the Waltz RV survey will soon start to target the long-period planet population orbiting the brightest giant stars in the northern hemisphere. We present the instrumental setup and first on-sky results of the Waltz RV survey, poised to join the few planet-hunting instruments located in Germany.

Author(s): Lukas Winkelmann Author, Juan Cabrera Author, Julian Bartholomäus Co-Author, Matthias Grott Co-Author, Harald Michealis Co-Author

Abstract:

Pointing performance is one of the main drivers for the photometric performance of small satellites. In particular, we refer to the ability of the payload to observe the same target at the same precise detector position over time scales that are relevant for scientific applications. One possible example is the detection and characterization of extrasolar planets or cometary bodies through photometric measurements using small satellites, which has great scientific potential, but requires extremely stringent pointing stability requirements.

To understand the impact of pointing performance on the photometric quality of the measurements obtained using small satellite platforms, we plan to measure at time scales relevant to exoplanetary science. These time scales can range from a few seconds to a few hours, including stellar activity, ingress and egress of planetary transits, and the transit duration of a planet or cometary body. Despite the significance of this information, it is not well documented how well small platforms can maintain pointing at different time scales, hindering our ability to accurately predict in-flight photometric performance.

Our goal is to develop a set of in-flight tests to measure the ability of TUBIN, a small satellite from the TU Berlin, to achieve a specific alignment and alignment stability performances. This study will assess our ability to achieve science goals such as the search for comets in extrasolar systems. We will investigate the feasibility of using small satellites for photometric observations of comets in extrasolar planetary systems and establish a model of the performance of the science instrumentation.

We intent to present preliminary results of the first imaging campaign as part of this study. This will provide valuable insights into the pointing performance of TUBIN and highlight any areas that need further improvement.