First Millimetric Detections of AE Aquarii

Ultrahigh Time Resolution Observations of Radio Bursts on AD Leonis

“…What is the alternative? One possibility is clearly the cyclotron maser instability (CMI ), a mechanism widely believed to play a significant role in planetary magnetospheres (see the recent review by Treumann 2006 and references therein) and long suspected of playing a role in the radio emission from the Sun (Melrose & Dulk 1982), stellar coronae (e.g., Bastian & Bookbinder 1987;Güdel et al 1989;Bastian et al 1990;Abada-Simon et al 1994;Bingham et al 2001), and, more recently, in the coronae of extremely late-type stellar and substellar objects (e.g., Hallinan et al 2007). The CMI is a resonant wave-particle phenomenon, the resonance being between electromagnetic waves and magnetized electrons.…”

Radio burst statistics for M dwarf flare stars

“…Assuming that the activity of the nine studied stars has not changed since they are observed at decimetric wavelengths, the burst rates inferred from the literature should be the same as the rates deduced from the reliable technique used between 1989 and 1993 (Lecacheux et al 1993;Abada-Simon et al 1994), under the two following conditions on the bursts reported in the publications: firstly, we only take into account the bursts for which the stellar origin is proven; secondly, we take into account only the bursts reaching at least 8 mJy, which is the peak flux density of the weakest burst detected during the Arecibo campaign.…”

“…This is the technique used during a 200 hour observing campaign with an acousto-optical spectrograph as a receiver of the Arecibo telescope. In the course of this campaign, which started in July 1989 and ended in February 1993, nine dMe flare stars and one binary system of the type RS Canum Venaticorum (RS CVn) were observed at 6 and 21 cm (Lecacheux et al 1993;Abada-Simon et al 1994). …”

“…The details on each of the eleven bursts detected from AD Leo in 38.3 hours of data are recalled in Table 1 (from Abada-Simon et al 1994). In summary, half of the bursts is circularly polarised, half is not; the bursts last between 6 and 90 s, and their peak flux density is between 8 and 63 mJy with an integration time of 1 s, but the strongest burst was in fact made of spikes reaching up to 350 mJy in 20 ms. Figure 1 shows a histogram of the eleven bursts' flux density.…”

Fireballs, Flares and Flickering

“…Clues come from multi-wavelength co-variability and orbital kinematics. Simultaneous VLA and optical observations show that the radio flux variations occur on similar timescales but are not correlated with the optical and ultraviolet flares, which therefore require a different mechanism (Abada-Simon et al 1995). It has been proposed that the flares represent modulations of the accretion rate onto the white dwarf, so that they should be correlated with X-ray variability.…”