Browsing by Author "Henning, Th."

Now showing 1 - 6 of 6
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    HATS-36b and 24 Other Transiting/Eclipsing Systems from the HATSouth-K2 Campaign 7 Program
    (2018) Bayliss. D.; Hartman, J.D.; Zhou, G.; Bakos, G.A.; Vanderburg, A.; Brahm Scott, Rafael; Jordán Colzani, Andrés Cristóbal; Espinoza, N.; Rabus, Markus; Suc, V.; Bento, J.; Mancini, L.; Ciceri, S.; Tan, T. G.; Penev, K.; Bhatti, W.; Vall-Borro, M. de; Csubry, Z.; Henning, Th.; Sarkis, P.; Lázár, J.; Papp, I.; Sári, P.
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    Orbital alignment and star-spot properties in the WASP-52 planetary system
    (OXFORD UNIV PRESS, 2017) Mancini, L.; Southworth, J.; Raia, G.; Tregloan Reed, J.; Molliere, P.; Bozza, V.; Bretton, M.; Bruni, I.; Ciceri, S.; D'Ago, G.; Dominik, M.; Hinse, T. C.; Hundertmark, M.; Jorgensen, U. G.; Korhonen, H.; Rabus, M.; Rahvar, S.; Starkey, D.; Novati, S. Calchi; Jaimes, R. Figuera; Henning, Th.; Juncher, D.; Haugbolle, T.; Kains, N.; Popovas, A.; Schmidt, R. W.; Skottfelt, J.; Snodgrass, C.; Surdej, J.; Wertz, O.
    We report 13 high-precision light curves of eight transits of the exoplanet WASP-52 b, obtained by using four medium-class telescopes, through different filters, and adopting the defocussing technique. One transit was recorded simultaneously from two different observatories and another one from the same site but with two different instruments, including a multiband camera. Anomalies were clearly detected in five light curves and modelled as star-spots occulted by the planet during the transit events. We fitted the clean light curves with the JKTEBOP code, and those with the anomalies with the PRISM + GEMC codes in order to simultaneously model the photometric parameters of the transits and the position, size and contrast of each star-spot. We used these new light curves and some from the literature to revise the physical properties of the WASP-52 system. Star-spots with similar characteristics were detected in four transits over a period of 43 d. In the hypothesis that we are dealing with the same star-spot, periodically occulted by the transiting planet, we estimated the projected orbital obliquity of WASP-52 b to be. = 3 degrees.8 +/- 8 degrees.4. We also determined the true orbital obliquity, psi = 20 degrees +/- 50 degrees, which is, although very uncertain, the first measurement of. purely from star-spot crossings. We finally assembled an optical transmission spectrum of the planet and searched for variations of its radius as a function of wavelength. Our analysis suggests a flat transmission spectrum within the experimental uncertainties.
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    Star-spot activity, orbital obliquity, transmission spectrum, physical properties, and transit time variations of the HATS-2 planetary system
    (2024) Biagiotti, F.; Mancini, L.; Southworth, J.; Tregloan-Reed, J.; Naponiello, L.; Jorgensen, U. G.; Bach-Moller, N.; Basilicata, M.; Bonavita, M.; Bozza, V.; Burgdorf, M. J.; Dominik, M.; Jaimes, R. Figuera; Henning, Th.; Hinse, T. C.; Hundertmark, M.; Khalouei, E.; Longa-Pena, P.; Peixinho, N.; Rabus, M.; Rahvar, S.; Sajadian, S.; Skottfelt, J.; Snodgrass, C.; Jongen, Y.; Vignes, J. -p
    Aims. Our aim in this paper is to refine the orbital and physical parameters of the HATS-2 planetary system and study transit timing variations and atmospheric composition thanks to transit observations that span more than 10 yr and that were collected using different instruments and pass-band filters. We also investigate the orbital alignment of the system by studying the anomalies in the transit light curves induced by starspots on the photosphere of the parent star. Methods. We analysed new transit events from both ground-based telescopes and NASA's TESS mission. Anomalies were detected in most of the light curves and modelled as starspots occulted by the planet during transit events. We fitted the clean and symmetric light curves with the JKTEBOP code and those affected by anomalies with the PRISM+GEMC codes to simultaneously model the photometric parameters of the transits and the position, size, and contrast of each starspot. Results. We found consistency between the values we found for the physical and orbital parameters and those from the discovery paper and ATLAS9 stellar atmospherical models. We identified different sets of consecutive starspot-crossing events that temporally occurred in less than five days. Under the hypothesis that we are dealing with the same starspots, occulted twice by the planet during two consecutive transits, we estimated the rotational period of the parent star and, in turn the projected and the true orbital obliquity of the planet. We find that the system is well aligned. We identified the possible presence of transit timing variations in the system, which can be caused by tidal orbital decay, and we derived a low-resolution transmission spectrum.
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    Sub-millimeter non-contaminated detection of the disk around TWA\\,7 by ALMA
    (2019) Bayo, A.; Olofsson, Johan; Matra, L.; Beamin Muhlenbrock, Juan Carlos; Gallardo, J.; de Gregorio-Monsalvo, I.; Booth, M.; Zamora, C.; Iglesias, D.; Henning, Th.; R. Schreiber, M.; Cáceres Acevedo, Claudio Cesar
    Debris disks can be seen as the left-overs of giant planet formation and the possible nurseries of rocky planets. While M-type stars out-number more massive stars we know very little about the time evolution of their circumstellar disks at ages older than $\sim 10$\,Myr. Sub-millimeter observations are best to provide first order estimates of the available mass reservoir and thus better constrain the evolution of such disks. Here, we present ALMA Cycle\,3 Band\,7 observations of the debris disk around the M2 star TWA\,7, which had been postulated to harbor two spatially separated dust belts, based on unresolved far-infrared and sub-millimeter data. We show that most of the emission at wavelengths longer than $\sim 300$\,$\mu$m is in fact arising from a contaminant source, most likely a sub-mm galaxy, located at about 6.6" East of TWA\,7 (in 2016). Fortunately, the high resolution of our ALMA data allows us to disentangle the contaminant emission from that of the disc and report a significant detection of the disk in the sub-millimeter for the first time with a flux density of 2.1$\pm$0.4 mJy at 870 $\mu$m. With this detection, we show that the SED can be reproduced with a single dust belt.
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    The 2014-2017 outburst of the young star ASASSN-13db A time-resolved picture of a very-low-mass star between EXors and FUors
    (2017) Sicilia Aguilar, A.; Oprandi, A.; Froebrich, D.; Fang, M.; Prieto, J. L.; Stanek, K.; Scholz, A.; Kochanek, C. S.; Henning, Th.; Rabus, Markus
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    Three Radial Gaps in the Disk of TW Hydrae Imaged with SPHERE
    (2017) Van Boekel, R.; Henning, Th.; Menu, J.; De Boer, J.; Langlois, M.; Müller, A.; Avenhaus, H.; Boccaletti, A.; Schmid, H. M.; Gómez-Lobo, Alfonso