scholarly journals Confirmation of the Electron Cyclotron Maser Instability as the Dominant Source of Radio Emission from Very Low Mass Stars and Brown Dwarfs

2008 ◽  
Vol 684 (1) ◽  
pp. 644-653 ◽  
Author(s):  
G. Hallinan ◽  
A. Antonova ◽  
J. G. Doyle ◽  
S. Bourke ◽  
C. Lane ◽  
...  
Keyword(s):  
Radio Emission ◽  
Brown Dwarfs ◽  
Electron Cyclotron ◽  
Low Mass Stars ◽  
Dominant Source ◽  
Electron Cyclotron Maser ◽  
Cyclotron Maser ◽  
Low Mass

scholarly journals Radio Emission from Ultrashort-Period Double Degenerate Binaries

2004 ◽  
Vol 21 (3) ◽  
pp. 248-251 ◽  
Author(s):  
A. J. Willes ◽  
K. Wu ◽  
Z. Kuncic
Keyword(s):  
Radio Emission ◽  
Flux Tube ◽  
Current System ◽  
Electron Cyclotron ◽  
Loss Cone ◽  
X Ray ◽  
Electron Cyclotron Maser ◽  
Cyclotron Maser ◽  
Theoretical Predictions ◽  
Orbital Periods

AbstractTiming measurements of periodic X-ray pulses from two ultrashort-period double degenerate binaries, RX J1914+24 and RX J0806+15, show that the rates of change of their orbital periods are consistent with gravitational radiation losses. This contradicts the predictions of models which invoke mass transfer between the two white dwarfs. The X-ray emission is, therefore, unlikely to be powered by accretion processes. The unipolar inductor model explains the source of X-ray emission as electrical dissipation at the base of a flux tube, which connects the magnetic white dwarf to its companion. This model is most consistent with the observed X-ray pulse properties. A similar current system exists in the Jupiter–Io system, where a mildly relativistic electron current produces an auroral footprint at the base of the Io flux tube and highly polarized beamed radio emission by means of the electron cyclotron maser mechanism. Detection of radio emission from RX J1914+24 and RX J0806+15 would thus provide further support for the unipolar inductor model. We present theoretical predictions, based on a loss-cone-driven electron cyclotron maser model, of radio fluxes from systems with parameters similar to RX J1914+24 and RX J0806+15.

scholarly journals Radio observations of HD 80606 near planetary periastron

2020 ◽  
Vol 644 ◽  
pp. A157
Author(s):  
F. de Gasperin ◽  
T. J. W. Lazio ◽  
M. Knapp
Keyword(s):  
Solar System ◽  
Radio Emission ◽  
Extrasolar Planets ◽  
Giant Planet ◽  
Electron Cyclotron ◽  
Polar Regions ◽  
Radio Observations ◽  
Radio Emissions ◽  
Electron Cyclotron Maser ◽  
Cyclotron Maser

Context. All the giant planets in the Solar System generate radio emission via electron cyclotron maser instability, giving rise most notably to Jupiter’s decametric emissions. An interaction with the solar wind is at least partially responsible for all of these Solar System electron cyclotron masers. HD 80606b is a giant planet with a highly eccentric orbit, leading to predictions that its radio emission may be enhanced substantially near periastron. Aims. This paper reports observations with the Low Frequency Array (LOFAR) of HD 80606b near its periastron in an effort to detect radio emissions generated by an electron cyclotron maser instability in the planet’s magnetosphere. Methods. The reported observations are at frequencies between 30 and 78 MHz, and they are distinguished from most previous radio observations of extrasolar planets by two factors: (i) they are at frequencies near 50 MHz, much closer to the frequencies at which Jupiter emits (ν < 40 MHz) and lower than most previously reported observations of extrasolar planets; and (ii) sensitivities of approximately a few millijanskys have been achieved, an order of magnitude or more below nearly all previous extrasolar planet observations below 100 MHz. Results. We do not detect any radio emissions from HD 80606b and use these observations to place new constraints on its radio luminosity. We also revisit whether the observations were conducted at a time when HD 80606b was super-Alfvénic relative to the host star’s stellar wind, which experience from the Solar System illustrates is a state in which an electron cyclotron maser emission can be sustained in a planet’s magnetic polar regions.

scholarly journals Primeval very low-mass stars and brown dwarfs – II. The most metal-poor substellar object

2017 ◽  
Vol 468 (1) ◽  
pp. 261-271 ◽  
Author(s):  
Z. H. Zhang 张曾华 ◽  
D. Homeier ◽  
D. J. Pinfield ◽  
N. Lodieu ◽  
H. R. A. Jones ◽  
...  
Keyword(s):  
Brown Dwarfs ◽  
Low Mass Stars ◽  
Low Mass

Slow-wave electron cyclotron maser

1988 ◽  
Vol 38 (6) ◽  
pp. 2883-2888 ◽  
Author(s):  
T. H. Kho ◽  
A. T. Lin
Keyword(s):  
Slow Wave ◽  
Electron Cyclotron ◽  
Electron Cyclotron Maser ◽  
Cyclotron Maser

scholarly journals A mid-infrared study of very low mass stars and brown dwarfs in Upper Scorpius

2006 ◽  
Vol 463 (2) ◽  
pp. 641-646 ◽  
Author(s):  
H. Bouy ◽  
N. Huélamo ◽  
E. L. Martín ◽  
D. Barrado y Navascués ◽  
M. Sterzik ◽  
...  
Keyword(s):  
Brown Dwarfs ◽  
Low Mass Stars ◽  
Infrared Study ◽  
Mid Infrared ◽  
Low Mass
Sign in / Sign up

Export Citation Format

Share Document