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Expected performances of the Characterising Exoplanet Satellite (CHEOPS). II. The CHEOPS simulator
DOI: 10.1051/0004-6361/201936616 Bibcode: 2020A&A...635A..23F

Queloz, D.; Benz, W.; Deline, A. +14 more

Context. The CHaracterising ExOPlanet Satellite (CHEOPS) is a mission dedicated to the search for exoplanetary transits through high precision photometry of bright stars already known to host planets. The telescope will provide the unique capability of determining accurate radii for planets whose masses have already been measured from ground-based…

2020 Astronomy and Astrophysics
CHEOPS Gaia 15
Small Impact Crater Populations on Saturn's Moon Tethys and Implications for Source Impactors in the System
DOI: 10.1029/2020JE006400 Bibcode: 2020JGRE..12506400F

Ferguson, S. N.; Rhoden, A. R.; Kirchoff, M. R.

Current estimates place the ages of the inner Saturnian satellites (Mimas, Enceladus, Tethys, Dione, and Rhea) between 4.5 Gyr and 100 Myr. These estimates are based on impact crater measurements and dynamical simulations, both of which have uncertainties. Models of satellite evolution are inherently simplified and rely on uncertain or unknown par…

2020 Journal of Geophysical Research (Planets)
Cassini 15
Beyond Gaia: Asteroseismic Distances of M Giants Using Ground-based Transient Surveys
DOI: 10.3847/1538-3881/ab91bf Bibcode: 2020AJ....160...18A

Kochanek, C. S.; Huber, Daniel; Tonry, John +14 more

Evolved stars near the tip of the red giant branch show solar-like oscillations with periods spanning hours to months and amplitudes ranging from ∼1 mmag to ∼100 mmag. The systematic detection of the resulting photometric variations with ground-based telescopes would enable the application of asteroseismology to a much larger and more distant samp…

2020 The Astronomical Journal
Gaia 15
Temporal and Periodic Variation of the MCMESI for the Last Two Solar Cycles; Comparison with the Number of Different Class X-ray Solar Flares
DOI: 10.1007/s11207-020-01711-2 Bibcode: 2020SoPh..295..159K

Kilcik, Ali; Chowdhury, Partha; Sarp, Volkan +4 more

In this study we compared the temporal and periodic variations of the Maximum CME Speed Index (MCMESI) and the the number of different class (C, M, and X) solar X-ray flares for the last two solar cycles (Solar Cycles 23 and 24). To obtain the correlation between the MCMESI and solar flare numbers the cross-correlation analysis was applied to mont…

2020 Solar Physics
SOHO 15
A Fully Kinetic Perspective of Electron Acceleration around a Weakly Outgassing Comet
DOI: 10.3847/2041-8213/ab6662 Bibcode: 2020ApJ...889L..33D

Henri, Pierre; Lapenta, Giovanni; Divin, Andrey +4 more

The cometary mission Rosetta has shown the presence of higher-than-expected suprathermal electron fluxes. In this study, using 3D fully kinetic electromagnetic simulations of the interaction of the solar wind with a comet, we constrain the kinetic mechanism that is responsible for the bulk electron energization that creates the suprathermal distri…

2020 The Astrophysical Journal
Rosetta 15
The Origin of a Distributed Stellar Population in the Star-forming Region W4
DOI: 10.3847/1538-4357/aba0a3 Bibcode: 2020ApJ...899..121L

Lim, Beomdu; Lee, Jeong-Eun; Yun, Hyeong-Sik +5 more

Stellar kinematics provides the key to understanding the formation process and dynamical evolution of stellar systems. Here, we present a kinematic study of the massive star-forming region (SFR) W4 in the Cassiopeia OB6 association using the Gaia Data Release 2 and high-resolution optical spectra. This SFR is composed of a core cluster (IC 1805) a…

2020 The Astrophysical Journal
Gaia 15
Multi-wavelength campaign on NGC 7469. VI. Photoionisation modelling of the emission line regions and the warm absorber
DOI: 10.1051/0004-6361/201935815 Bibcode: 2020A&A...633A..62G

Kriss, G. A.; Arav, N.; Bianchi, S. +16 more


Aims: We aim to investigate and characterise the photoionised X-ray emission line regions within the Seyfert 1 galaxy NGC 7469.
Methods: We applied the photoionisation model, PION, within the spectral fitting code SPEX to analyse the 640 ks reflection grating spectrometer spectrum of NGC 7469 gathered during an XMM-Newton observing campa…

2020 Astronomy and Astrophysics
XMM-Newton 15
2003-2019 Monitoring of the Crab Emission through INTEGRAL SPI, or Vice Versa
DOI: 10.3847/1538-4357/aba8a4 Bibcode: 2020ApJ...899..131J

Jourdain, E.; Roques, J. P.

The Crab Nebula is used by many instruments as a calibration source, in particular at high energy, where it is one of the brightest celestial objects. The spectrometer INTEGRAL SPI (20 keV-8 MeV), in operation since 2002 October, offers a large data set dedicated to this source, with regular campaigns planned twice per year. We have analyzed the a…

2020 The Astrophysical Journal
INTEGRAL 15
Evidence for magnetic activity at starbirth: a powerful X-ray flare from the Class 0 protostar HOPS 383
DOI: 10.1051/0004-6361/202038185 Bibcode: 2020A&A...638L...4G

Hamaguchi, Kenji; Kastner, Joel H.; Principe, David A. +1 more

Context. Class 0 protostars represent the earliest evolutionary stage of solar-type stars, during which the majority of the system mass resides in an infalling envelope of gas and dust and is not yet in the central, nascent star. Although X-rays are a key signature of magnetic activity in more evolved protostars and young stars, whether such magne…

2020 Astronomy and Astrophysics
Gaia 15
The UV Perspective of Low-Mass Star Formation
DOI: 10.3390/galaxies8010027 Bibcode: 2020Galax...8...27S

France, Kevin; Schneider, P. Christian; Günther, H. Moritz

The formation of low-mass (M★≲2M⊙) stars in molecular clouds involves accretion disks and jets, which are of broad astrophysical interest. Accreting stars represent the closest examples of these phenomena. Star and planet formation are also intimately connected, setting the starting point for planetary systems like our own. The ultraviolet (UV) sp…

2020 Galaxies
eHST 15