TY  - JOUR
A1  - Schöller, Markus
A1  - Hubrig, Swetlana
A1  - Fossati, L.
A1  - Carroll, Thorsten Anthony
A1  - Briquet, Maryline
A1  - Oskinova, Lidia M.
A1  - Järvinen, S.
A1  - Ilyin, Ilya
A1  - Castro, N.
A1  - Morel, T.
A1  - Langer, N.
A1  - Przybilla, N.
A1  - Nieva, M. -F.
A1  - Kholtygin, A. F.
A1  - Sana, H.
A1  - Herrero, A.
A1  - Barba, R. H.
A1  - de Koter, A.
T1  - B fields in OB stars (BOB)
BT  - Concluding the FORS2 observing campaign
JF  - Astronomy and astrophysics : an international weekly journal
N2  - Aims. The B fields in OB stars (BOB) Collaboration is based on an ESO Large Programme to study the occurrence rate, properties, and ultimately the origin of magnetic fields in massive stars. Methods. In the framework of this program, we carried out low-resolution spectropolarimetric observations of a large sample of massive stars using FORS2 installed at the ESO VLT 8m telescope. Results. We determined the magnetic field values with two completely independent reduction and analysis pipelines. Our in-depth study of the magnetic field measurements shows that differences between our two pipelines are usually well within 3 sigma errors. From the 32 observations of 28 OB stars, we were able to monitor the magnetic fields in CPD -57 degrees 3509 and HD164492C, confirm the magnetic field in HD54879, and detect a magnetic field in CPD -62 degrees 2124. We obtain a magnetic field detection rate of 6 +/- 3% for the full sample of 69 OB stars observed with FORS 2 within the BOB program. For the preselected objects with a nu sin i below 60 km s(-1), we obtain a magnetic field detection rate of 5 +/- 5%. We also discuss X-ray properties and multiplicity of the objects in our FORS2 sample with respect to the magnetic field detections.
KW  - polarization
KW  - stars: early-type
KW  - stars: magnetic field
KW  - stars: massive
Y1  - 2017
U6  - https://doi.org/10.1051/0004-6361/201628905
SN  - 1432-0746
VL  - 599
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Keles, Engin
A1  - Mallonn, Matthias
A1  - Kitzmann, Daniel
A1  - Poppenhäger, Katja
A1  - Hoeijmakers, H. Jens
A1  - Ilyin, Ilya
A1  - Alexoudi, Xanthippi
A1  - Carroll, Thorsten A.
A1  - Alvarado-Gomez, Julian
A1  - Ketzer, Laura
A1  - Bonomo, Aldo S.
A1  - Borsa, Francesco
A1  - Gaudi, B. Scott
A1  - Henning, Thomas
A1  - Malavolta, Luca
A1  - Molaverdikhani, Karan
A1  - Nascimbeni, Valerio
A1  - Patience, Jennifer
A1  - Pino, Lorenzo
A1  - Scandariato, Gaetano
A1  - Schlawin, Everett
A1  - Shkolnik, Evgenya
A1  - Sicilia, Daniela
A1  - Sozzetti, Alessandro
A1  - Foster, Mary G.
A1  - Veillet, Christian
A1  - Wang, Ji
A1  - Yan, Fei
A1  - Strassmeier, Klaus G.
T1  - The PEPSI exoplanet transit survey (PETS) I: Investigating the presence of a silicate atmosphere on the super-earth 55 Cnc e
JF  - Monthly notices of the Royal Astronomical Society
N2  - The study of exoplanets and especially their atmospheres can reveal key insights on their evolution by identifying specific atmospheric species. For such atmospheric investigations, high-resolution transmission spectroscopy has shown great success, especially for Jupiter-type planets. Towards the atmospheric characterization of smaller planets, the super-Earth exoplanet 55 Cnc e is one of the most promising terrestrial exoplanets studied to date. Here, we present a high-resolution spectroscopic transit observation of this planet, acquired with the PEPSI instrument at the Large Binocular Telescope. Assuming the presence of Earth-like crust species on the surface of 55 Cnc e, from which a possible silicate-vapor atmosphere could have originated, we search in its transmission spectrum for absorption of various atomic and ionized species such as Fe , Fe (+), Ca , Ca (+), Mg, and K , among others. Not finding absorption for any of the investigated species, we are able to set absorption limits with a median value of 1.9 x R-P. In conclusion, we do not find evidence of a widely extended silicate envelope on this super-Earth reaching several planetary radii.
KW  - planets and satellites: atmospheres
KW  - planets and satellites: composition
Y1  - 2022
U6  - https://doi.org/10.1093/mnras/stac810
SN  - 0035-8711
SN  - 1365-2966
VL  - 513
IS  - 1
SP  - 1544
EP  - 1556
PB  - Oxford University Press
CY  - Oxford
ER  -