The space weather around the exoplanet GJ 436b: I. The large-scale stellar magnetic field

Stars and planetary system

TOI-1759 b: A transiting sub-Neptune around a low mass star characterized with SPIRou and TESS

Stars and planetary system

Can the magnetic topology of AB Doradus be explained by a potential field distribution

Original paper can be found at: http://www.astrosociety.org/pubs/cs/195-221.html--Copyright Astronomical Society of the PacificWe present potential magnetic field maps of the surface of the active KO dwarf, AB Dor. Maps of the surface magnetic flux distributions of rapid rotators can be produced using the technique of Zeeman Doppler imaging (ZDI). Magnetic flux maps of active cool stars produced using ZDI show many features that have no solar counterpart. Currently, ZDI codes map only the simplest possible magnetic field distributions that will fit the observed data. It remains unclear how physically realistic these maps really are and this is what we are concerned with here

Submillimetre continuum emission from class 0 sources: Theory, observations, and modelling

We report on a study of the thermal dust emission of the circumstellar envelopes of a sample of Class 0 sources. The physical structure (geometry, radial intensity profile, spatial temperature and spectral energy distribution) and properties (mass, size, bolometric luminosity (Lbol), temperature (Tbol), and age) of Class 0 sources are derived here in an evolutionary context. This is done by combining SCUBA imaging at 450 and 850 μm of the thermal dust emission of envelopes of Class 0 sources in the Perseus and Orion molecular cloud complexes with a model of the envelope, with the implementation of techniques like the black-body fitting and radiative transfer calculations of dusty envelopes, and with the Smith evolutionary model for protostars. The modelling results obtained here confirm the validity of a simple spherical symmetric model envelope, and the assumptions about density and dust distributions following the standard envelope model. The spherically model reproduces reasonably well the observed SEDs and the radial profiles of the sources. The implications of the derived properties for protostellar evolution are illustrated by analysis of the Lbol, the Tbol, and the power-law index p of the density distribution for a sample of Class 0 sources

Observing Dynamos in Cool Stars

The main aim of this paper is to introduce the most important observables that help us to investigate stellar dynamos and compare those to the modeling results. We give an overview of the available observational methods and data processing techniques that are suitable for such purposes, with touching upon examples of inadequate interpretations as well. Stellar observations are compared to the solar data in such a way, which ensures that the measurements are comparable in dimension, wavelength, and timescale. A brief outlook is given to the future plans and possibilities. A thorough review of this topic was published nearly a decade ago (Berdyugina 2005), now we focus on the experience that have been gathered since that time.Comment: 47 pages, accepted for publication in Space Science Review