Related papers: A magnetic field evolution scenario for brown dwar…
Several recent papers conclude that radio-pulsar magnetic fields decay on a time-scale of 10 Myr, apparently contradicting earlier results. We have implemented the methods of these papers in our code and show that this preference for rapid…
Parker Solar Probe and Solar Orbiter data are used to investigate the radial evolution of magnetic turbulence between $0.06 ~ \lesssim R ~\lesssim 1$ au. The spectrum is studied as a function of scale, normalized to the ion inertial scale…
The magnetic white dwarf SDSS J121209.31+013627.7 exhibits a weak, narrow Halpha emission line whose radial velocity and strength are modulated on a period of ~90 minutes. Though indicative of irradiation on a nearby companion, no cool…
We report on searches for radio emission from three of the nearest known young brown dwarfs using the Very Large Array. We have obtained sensitive upper limits on 3.6cm emission from 2MASSW J1207334-393254, TWA~5B and SSSPM J1102-3431, all…
Radio and X-ray emission from brown dwarfs suggest that an ionised gas and a magnetic field with a sufficient flux density must be present. We perform a reference study for late M-dwarfs, brown dwarfs and giant gas planet to identify which…
We discuss the evolution of the magnetic field of an accreting white dwarf. We first show that the timescale for ohmic decay in the liquid interior is 8 to 12 billion years for a dipole field, and 4 to 6 billion years for a quadrupole…
Evidence of star-planet interactions in the form of planet-modulated chromospheric emission has been noted for a number of hot Jupiters. Magnetic star-planet interactions involve the release of energy stored in the stellar and planetary…
We present stellar wind modelling of the hot Jupiter host HD189733, and predict radio emission from the stellar wind and the planet, the latter arising from the interaction of the stellar wind with the planetary magnetosphere. Our stellar…
M dwarfs are the most abundant stars in the Galaxy and exhibit diverse magnetic behaviours. Understanding their large-scale magnetic fields is essential to study stellar dynamos and assess the impact of magnetic activity on planetary…
The search for exoplanets in the radio bands has been focused on detecting radio emissions produced by the interaction between magnetized planets and the stellar wind (auroral emission). Here we introduce a new tool, which is part of our…
The search for radio emission from extra-solar planets has so far been unsuccessful. Much of the effort in modelling the predicted emission has been based on the analogy with the well-known emission from Jupiter. Unlike Jupiter, however,…
At metallicities lower than that of the Small Magellanic Cloud, it remains essentially unexplored how fossil magnetic fields, forming large-scale magnetospheres, could affect the evolution of massive stars, thereby impacting the fundamental…
Violent gravitational interactions can change the morphologies of galaxies and, by means of merging, transform them into elliptical galaxies. We aim to investigate how they affect the evolution of galactic magnetic fields. We selected 16…
Context. Close-in giant extrasolar planets (''Hot Jupiters'') are believed to be strong emitters in the decametric radio range. Aims. We present the expected characteristics of the low-frequency magnetospheric radio emission of all…
We investigate the migration of massive extrasolar planets due to gravitational interaction with a viscous protoplanetary disc. We show that a model in which planets form at 5 AU at a constant rate, before migrating, leads to a predicted…
Context. Red-giant stars may engulf planets. This may increase the rotation rate of their convective envelope, which could lead to strong dynamo-triggered magnetic fields. Aims. We explore the possibility of generating magnetic fields in…
Estimations of magnetic fields of neutron stars, observed as radio and X-ray pulsars, are discussed. It is shown, that theoretical and observational values for different types of radiopulsars are in good correspondence. Radiopulsars in…
We report the first direct detection of a strong, 5 kG magnetic field on the surface of an active brown dwarf. LSR J1835+3259 is an M8.5 dwarf exhibiting transient radio and optical emission bursts modulated by fast rotation. We have…
Surface magnetic fields have a strong impact on stellar mass loss and rotation and, as a consequence, on the evolution of massive stars. In this work we study the influence of an evolving dipolar surface fossil magnetic field with an…
This paper suggests the idea that all neutron stars experienced at birth an ultrafast decay of their magnetic fields from their initial values to their current surface values. If the electromagnetic energy radiated during this field decay…