Coherent Radio Bursts from RS CVn Binareis

Periodic Bursts of Coherent Radio Emission from an Ultracool Dwarf

We report the detection of periodic (p = 1.96 hours) bursts of extremely bright, 100% circularly polarized, coherent radio emission from the M9 dwarf TVLM 513-46546. Simultaneous photometric monitoring observations have established this periodicity to be the rotation period of the dwarf. These bursts, which were not present in previous observations of this target, confirm that ultracool dwarfs ...

Quiescent and Flaring Structure in Rs Cvn

VLA multifrequency observations of RS CVn binaries

We present multiepoch Very Large Array (VLA) observations at 1.4 GHz, 4.9 GHz, 8.5 GHz and 14.9 GHz for a sample of eight RS CVn binary systems. Circular polarization measurements of these systems are also reported. Most of the fluxes observed are consistent with incoherent emission from mildly relativistic electrons. Several systems show an increase of the degree of circular polarization with ...

A NON-EMPIRICAL ROTATION-ACTIVITY RELATION FOR RS CVn BINARIES USING RADIO LUMINOSITIES

An analysis of a comprehensive survey of radio luminosities for RS CVn binary systems is given. A comparison is made between the rotation-activity correlations found using the usual semi-empirical Rossby number and a Rossby number deduced from detailed convection zone models. The use of a non-empirically derived Rossby number does not signiicantly improve the rotation-activity correlation. Alth...

A probable RS CVn star which sometimes stops its eclipses ⋆

We report the discovery of a new variable star, called S 10947 Aql, as the likely optical counterpart of RX J2009.8+1557. The optical variability pattern as well as the detected X-ray emission suggest that it is a chromospherically active binary of the RS Canum Venaticorum (≡ RS CVn) type. We discovered an occasional disappearance of the eclipsing minima as well as large variations in the eclip...