Statistical Analysis and the OPEA Model of the White-Light Flares Occurring on Krüger 60B (DO Cep)

Dal, H. A.

doi:10.1071/as11034

Cited by 3 publications

(1 citation statement)

References 35 publications

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“…The cumulative flare frequency (in seconds) versus U-band flare energy (in erg) for a large group of M dwarfs plus that for KIC 5464065 and KIC 9726699. These data have been compiled from the work by Moffett (1974), Lacy et al (1976), Byrne et al (1984) and Byrne, Doyle & Menzies (1985), Pettersen (1975aPettersen ( ,b, 1981aPettersen ( ,b, 1983Pettersen ( , 1985aPettersen ( ,b, 2006a, Pettersen, Kern & Evans (1983), Pettersen, Coleman & Evans (1984) and Pettersen et al (1986), Pettersen & Sundland (1991), , Doyle, Byrne & Butler (1986), Doyle, van Oord & Butler (1989) and Doyle et al (1990), Hawley et al (1989), Leto et al (1997), Dal & Evren (2010 and Dal (2011Dal ( , 2012 than one order of magnitude than the largest flare seen on KIC 5474065. Segura et al (2010) determined that such a flare was not a direct hazard for life (as we know it) on an exoplanet 0.16 au distant from AD Leo.…”

Section: T H E I M Pac T O F F L a R E S I N T H E I M M E D I At E Smentioning

confidence: 99%

Short-duration high-amplitude flares detected on the M dwarf star KIC 5474065

Ramsay

Doyle

Hakala

et al. 2013

Monthly Notices of the Royal Astronomical Society

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Using data obtained during the RATS-Kepler project, we identified one short-duration flare in a 1 h sequence of ground-based photometry of the dwarf star KIC 5474065. Observations made using Gran Telescopio Canarias show that it is a star with an M4V spectral type. Kepler observations made using 1 min sampling show that KIC 5474065 exhibits large-amplitude (δF/F > 0.4) optical flares which have a duration as short as 10 min. We compare the energy distribution of flares from KIC 5474065 with that of KIC 9726699, which has also been observed using 1-min sampling, and ground-based observations of other M dwarf stars in the literature. We discuss the possible implications these short-duration, relatively low-energy flares would have on the atmosphere of exoplanets orbiting in the habitable zone of these flare stars.

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Section: T H E I M Pac T O F F L a R E S I N T H E I M M E D I At E Smentioning

confidence: 99%

Short-duration high-amplitude flares detected on the M dwarf star KIC 5474065

Ramsay

Doyle

Hakala

et al. 2013

Monthly Notices of the Royal Astronomical Society

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The flare cumulative frequencies of UV Ceti stars from different spectral types

Dal

2020

Monthly Notices of the Royal Astronomical Society

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In this study, as a result of the photometric observations continued on nine UV Ceti type stars, examining the parameters obtained from the models of distributions of the flare equivalent durations in the logarithmic scale versus flare total durations, it is found that the highest flare equivalent durations occurring on the stars (Plateau values) are varying with the B − V colour indexes of those stars in agreement with the variations of both the magnetic field strength (B) of the magnetic loop and especially the electron density of its plasma (ne). The distributions of flare cumulative frequencies were derived by using the flare equivalent durations, instead of the flare energy. The main result of this study is a secondary variation, which can be just modelled with the damping sine waves, behind the main exponential variation of the flare cumulative frequency. The models indicate that this secondary variation in the flare cumulative frequency distributions is in the same shape with the periodic or quasi-periodic oscillations detected in the light curves of the stellar and solar flares. This caused to ask new questions about the flare mechanism working on stellar atmospheres.

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Statistical Analyses of White-Light Flares: Two Main Results about Flare Behaviour

Dal¹

2012

Publications of the Astronomical Society of Japan

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We present two main results, based on the models and the statistical analyses of 1672 U-band flares. We also discuss the behaviours of the white-light flares. In addition, the parameters of the flares detected from two years of observations on CR Dra are presented. By comparing with the flare parameters obtained from other UV Ceti type stars, we examine the behaviour of optical flare processes along the spectral types. Moreover, we aimed, using large white-light flare data,to analyse the flare time-scales in respect to some results obtained from the X-ray observations. Using the SPSS V17.0 and the GraphPad Prism V5.02 software, the flares detected from CR Dra were modelled with the OPEA function and analysed with t-Test method to compare similar flare events in other stars. In addition, using some regression calculations in order to derive the best histograms, the time-scales of the white-light flares were analysed. Firstly, CR Dra flares have revealed that the white-light flares behave in a similar way as their counterparts observed in X-rays. As seen in X-ray observations, the electron density seems to be a dominant parameter in white-light flare process, too. Secondly, the distributions of the flare time-scales demonstrate that the number of observed flares gets a maximum value in some particular ratios, which are 0.5 or its multiples, and especially positive integers. The thermal processes might be dominant for these white-light flares, while non-thermal processes might be dominant in the others. To reach better results for the behaviour of the white-light flare process along the spectral types, much more stars in a wide spectral range, from the spectral type dK5e to dM6e, must be observed in the white-light flare patrols.

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Statistical Analysis and the OPEA Model of the White-Light Flares Occurring on Krüger 60B (DO Cep)

Cited by 3 publications

References 35 publications

Short-duration high-amplitude flares detected on the M dwarf star KIC 5474065

Short-duration high-amplitude flares detected on the M dwarf star KIC 5474065

The flare cumulative frequencies of UV Ceti stars from different spectral types

Statistical Analyses of White-Light Flares: Two Main Results about Flare Behaviour

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