Rotation Modulations and Distributions of the Flare Occurrence Rates on the Surface of Five UV Ceti Type Stars

Dal, H. A.; Evren, S.

doi:10.1093/pasj/63.2.427

Cited by 12 publications

(13 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Byrne et al (1984) reported a period P = 4.565 d. Later, Amado et al (2001) reported a period P = 4.399 d detected in two consecutive years at the South African Astronomical Observatory. The most recent period determination P = 4.4236 d is reported by Dal & Evren (2011) and it was obtained in two consecutive years. Our LS and CLEAN analyses of ASAS time series show the following periods in all seasons (as well as in the complete series) in order of decreasing power: P = 4.42 d, P = 1.29 d, P = 2.2 d, and P = 1.83 d (see Fig.…”

Section: -2mass J04435686+3723033 (V 962 Per)mentioning

confidence: 99%

TheβPictoris association: Catalog of photometric rotational periods of low-mass members and candidate members

Messina

Millward²,

Buccino

et al. 2017

A&A

View full text Add to dashboard Cite

Aims. We intended to compile the most complete catalog of bona fide members and candidate members of the β Pictoris association, and to measure their rotation periods and basic properties from our own observations, public archives, and exploring the literature. Methods. We carried out a multi-observatories campaign to get our own photometric time series and collected all archived public photometric data time series for the stars in our catalog. Each time series was analyzed with the Lomb-Scargle and CLEAN periodograms to search for the stellar rotation periods. We complemented the measured rotational properties with detailed information on multiplicity, membership, and projected rotational velocity available in the literature and discussed star by star. Results. We measured the rotation periods of 112 out of 117 among bona fide members and candidate members of the β Pictoris association and, whenever possible, we also measured the luminosity, radius, and inclination of the stellar rotation axis. This represents to date the largest catalog of rotation periods of any young loose stellar association. Conclusions. We provided an extensive catalog of rotation periods together with other relevant basic properties useful to explore a number of open issues, such as the causes of spread of rotation periods among coeval stars, evolution of angular momentum, and lithium-rotation connection.

show abstract

Section: -2mass J04435686+3723033 (V 962 Per)mentioning

confidence: 99%

TheβPictoris association: Catalog of photometric rotational periods of low-mass members and candidate members

Messina

Millward²,

Buccino

et al. 2017

A&A

View full text Add to dashboard Cite

show abstract

“…To understand whether the flares observed from DK CVn, which is an eclipsing binary system, are similar to the flares occurring on the surface of UV Ceti type stars, DK CVn's flares were compared with B band flares of five UV Ceti type stars presented by Dal & Evren (2011). To be able to compare them, first of all, following the method developed by Dal & Evren (2011), the distribution of the flare equivalent durations versus flare total durations were derived for B band flares of DK CVn. Using SPSS V17.0 software (Green et al 1999) and GrahpPad Prism V5.02 software (Motulsky 2007;Dawson & Trapp 2004), the best model function was determined.…”

Section: Flare Activitymentioning

confidence: 99%

“…All the parameters listed in Table 6 were compared with the parameters given by Dal & Evren (2011) for five UV Ceti type stars. In the comparison, we assume that the flares are occurring on the surface of the cool component of the system.…”

Section: Flare Activitymentioning

confidence: 99%

The Nature of the Light Variation of the Unique Binary DK CVn

Dal

Sipahi

Özdarcan

2012

Publ. – Astron. Soc. Aust

View full text Add to dashboard Cite

Abstract:We present BVR observations of DK CVn from 2007 and 2008. We analysed the BVR light curves of the system and obtained the system's parameters. Using the 'q-search' method, we measured the mass ratio of the system (q) as 0.55. Taking the temperature of the primary component as 4040 K, the temperature of the secondary was found to be 3123 K. Several flares were detected, and the distributions of flare equivalent duration versus flare total duration were modelled using the One-Phase Exponential Association Function for these flares. The parameters of the model demonstrated that the flares are the same as those detected from UV Ceti stars. We also demonstrate that the variation at out-of-eclipse must be caused by some cool spot(s) on one of the components. The star is found to show two active longitudes in which the spots are mainly formed. Consequently, this study reveals that DK CVn should be a chromospherically active binary star.

show abstract

“…According to the results obtained from the first iterations, the secondary component seems to be an M dwarf, which is close to the full-convective boundary (Browning 2011). Full-convective M dwarfs exhibit very strong flare activity, while a few of them purely exhibit spot activity (Dal & Evren 2011). In addition, if the secondary component is the spotted one, to remove the asymmetries seen in the light curves the analysis demonstrated that the spots should be large enough to cover the entire surface of the star or else their effective temperatures must be half of the surface temperature due to the secondary component's light rate in the total light of the system.…”

Section: Light-curve Analysismentioning

confidence: 99%

High-Level Magnetic Activity on a Low-Mass Close Binary: GSC 02038-0293

Dal

Sipahi

Özdarcan

2012

Publ. – Astron. Soc. Aust

View full text Add to dashboard Cite

Taking into account results obtained from light-curve analysis and out-of-eclipse analyses, we discuss the nature of GSC 02038-00293 and also its magnetic activity behaviour. We obtained light curves of the system during observing seasons 2007, 2008 and 2011. We obtained its secondary minimum clearly in I-band observations in 2008 for the first time. Analysing this light curve, we found the physical parameters of the components. The light-curve analysis indicates that the possible mass ratio of the system is 0.35. We obtained the remaining V-band light curves, extracting the eclipses. We modelled these remaining curves using the SPOTMODEL program and found possible spot configurations of the magnetically active component for each observing season. The models demonstrated that there are two active longitudes for the active component. The models reveal that both active longitudes migrate in the direction of decreasing longitude. We also examined the light curves in out-of-eclipse phases with respect to minimum and maximum brightness, amplitude, etc. The amplitude of the curves during out-of-eclipse phases varies in a sinusoidal way with a period of ,8.9 yr; the mean brightness of the system is dramatically decreasing. The phases of the deeper minimum during out-of-eclipse periods exhibit a migration toward decreasing phase.

show abstract

Rotation Modulations and Distributions of the Flare Occurrence Rates on the Surface of Five UV Ceti Type Stars

Cited by 12 publications

References 54 publications

TheβPictoris association: Catalog of photometric rotational periods of low-mass members and candidate members

TheβPictoris association: Catalog of photometric rotational periods of low-mass members and candidate members

The Nature of the Light Variation of the Unique Binary DK CVn

High-Level Magnetic Activity on a Low-Mass Close Binary: GSC 02038-0293

Contact Info

Product

Resources

About