Search Publications
Phase locking among Saturn radio emissions revealed by Cassini observations
Xu, Yan; Fischer, Georg; Yao, Zhonghua +7 more
Context. Rotational modulation has been observed in different magnetospheric phenomena at Saturn, including radio emissions, which reflect the fundamental plasma processes in key regions. Though previous studies have shown Saturn's kilometric radiation, 5 kHz narrowband emissions, and auroral hiss to be rotationally modulated, the modulation featu…
A trio of month-long flares in the nova-like variable V704 And
Pringle, J. E.; Naylor, T.; Page, K. L. +2 more
We present the discovery of an unusual set of flares in the nova-like variable V704 And. Using data from AAVSO, ASAS-SN, and ZTF for the nova-like variable V704 And, we discovered a trio of brightening events that occurred during the high state. These events elevate the optical brightness of the source from ∼13.5 to ∼12.5 mag. The events last for …
Relation between spectral indices and binary fractions in globular clusters
Li, L.; Han, Z.; Zhang, F. +1 more
Context. We study the relation between the known binary fraction and spectral absorption feature index to judge whether (and potentially which) spectral absorption feature indices are suitable for determining the binary fraction.
Aims: The determination of the binary fraction is important in studies of binary star formation, evolutionary popu…
The X-ray activity of F stars with hot Jupiters: KELT-24 versus WASP-18
Micela, G.; Pillitteri, I.; Wolk, S. J. +1 more
X-rays emitted by the coronae of solar-type stars are a feature present in up to late-A types during the main sequence phase. F stars, either with or without hot Jupiters, are usually X-ray emitters. The very low level of X-ray emission of the F5 star WASP-18 despite its relatively young age and spectral type is thus quite peculiar. In this paper …
XMM-Newton observation of the TeV-discovered supernova remnant HESS J1534-571
Santangelo, A.; Pühlhofer, G.; Sasaki, M. +3 more
We report the results obtained from XMM-Newton observations of the TeV-detected supernova remnant (SNR) HESS J1534-571. We focus on the nature of the cosmic-ray particle content in the SNR, which is revealed by its γ-ray emission. No signatures of X-ray synchrotron emission were detected from the SNR. This is consistent with earlier results obtain…
Two-horn quiescent prominence observed in Hα and Mg II h&k lines with THEMIS and IRIS
Barczynski, Krzysztof; Schmieder, Brigitte; Labrosse, Nicolas +2 more
Context. Prominences are large magnetic structures in the corona filled by cool plasma with fast evolving fine structure.
Aims: We aim to better understand the plasma conditions in the fine structure of a quiescent prominence including two transient horns observed at the bottom of the cavity using the high resolution Interface Region Imaging …
High-contrast detection of exoplanets with a kernel-nuller at the VLTI
Ireland, Michael J.; Martinache, Frantz; N'Diaye, Mamadou +5 more
Context. The conventional approach to direct imaging is to use a single aperture coronagraph with wavefront correction via extreme adaptive optics (AO). Such systems are limited to observing beyond an inner working angle (IWA) of a few λ/D. Nulling interferometry with two or more apertures will enable detections of companions at separations at and…
Testing ultralow amplitude Cepheid candidates in the Galactic disk by TESS and Gaia
Bódi, Attila; Szabó, Róbert; Molnár, László +1 more
Ultralow amplitude (ULA) and strange mode Cepheids are thought to be pulsating variable stars that are near to or are at the edges of the classical instability strip. Until now, a few dozen such variable star candidates have been found both in the Large Magellanic Cloud and the Milky Way. For the present work, we studied six ULA Cepheid candidates…
Exploring the environment, magnetic fields, and feedback effects of massive high-redshift galaxies with [C II]
Knudsen, K. K.; König, S.; Gullberg, B. +3 more
Context. Massive galaxies are expected to grow through different transformative evolutionary phases. High-redshift starburst galaxies and quasars are thought to be such phases and thus provide insight into galaxy evolution. Several physical mechanisms are predicted to play an important role in driving these phases; for example, interaction with co…
Study of a sample of faint Be stars in the exofield of CoRoT. III. Global spectroscopic characterization and astrophysical parameters of the central stars
Frémat, Y.; Zorec, J.; Hubert, A. M. +1 more
Context. The search and interpretation of non-radial pulsations from Be star light curves observed with the CoRoT satellite requires high-quality stellar astrophysical parameters.
Aims: The present work is devoted to the spectroscopic study of a sample of faint Be stars observed by CoRoT in the fourth long run (LRA02).
Methods: The astro…