scholarly journals Statistics of flares observed for UV Ceti type stars YZ CMi, AD Leo, and EV Lac at the Okayama Observatory

1990 ◽  
Vol 137 ◽  
pp. 43-47
Author(s):  
K. Ishida
Keyword(s):  
Time Resolution ◽  
High Time ◽  
High Time Resolution ◽  
Ceti Type ◽  
Flare Stars ◽  
Ev Lac

Photoelectric monitoring of flare stars YZ CMi, AD Leo, and EV Lac has been done at the Okayama Observatory since early 1970s. This is a simultaneous UBV observations with a high time resolution. Some statistics of the flares of the UV Ceti type stars are presented.

scholarly journals Two-colour observations of spikes and flares by high time resolution

1990 ◽  
Vol 137 ◽  
pp. 33-34
Author(s):  
V.P. Zalinian ◽  
A.A. Karapetian ◽  
H.M. Tovmassian
Keyword(s):  
Time Resolution ◽  
High Time ◽  
High Time Resolution ◽  
Long Duration ◽  
Flare Stars ◽  
Ev Lac

Observations of flare stars with high time resolution permit to register spiky type flares and also to study in detail bright curves of flares. In Byurakan observatory observations of EV Lac have been made with 0.1 s time resolution simultaneouslyin two filters “U” and “B” [1-3]. These observations permited to detect flares of a burst type (Fig.1) and also to reveil multipeak structure of long duration flares. It is necessary to stress that simultaneous observations in two colours increas appresiably the thrustworthiness of the registered spiky flares.

scholarly journals A New Technique for Precise Stellar Photometry: Application to Small-Scale Activity of EV Lacertae

1995 ◽  
Vol 151 ◽  
pp. 133-134 ◽  
Author(s):  
B.E. Zhilyaev
Keyword(s):  
Time Resolution ◽  
High Time ◽  
Small Scale ◽  
High Time Resolution ◽  
Stellar Photometry ◽  
A New Technique ◽  
Ev Lac ◽  
Counting Statistics ◽  
Simple Integration ◽  
Resolution Data

AbstractA new prefiltering technique (PFT) for precise stellar photometry is described. It has been proved that the prefiltered and added high-time resolution data provide an increase in S/N ratio by factors 1.3 — 1.7 in comparison with simple integration. The PFT allows to detect event amplitudes which are comparable to that caused by counting statistics. Adopting the PFT, our observations reveal small-scale flare events in the subsecond range in EV Lac.

scholarly journals A short-lived flare of EV Lacertae

1990 ◽  
Vol 137 ◽  
pp. 35-36
Author(s):  
B. E. Zhilyaev ◽  
Ya. O. Romanjuk ◽  
O. A. Svyatogorov
Keyword(s):  
Fine Structure ◽  
Light Curve ◽  
Time Resolution ◽  
Time Scale ◽  
High Time ◽  
High Time Resolution ◽  
Decay Times ◽  
Ev Lac

Flare events on a time scale of the order of one second were observed on EV Lac by Gershberg and Petrov [1], Zalinian and Tovmassian [2], Tsvetkov, Antov and Tsvetkova [3]. The nature of such phenomena is very mysterious. We hope that monitoring of EV Lac with high time resolution will yield the information about growing and decay times as well as fine structure of the light curve and color one. A short-lived flare of EV Lac was recorded in U and V bands in 1989, September 3 2h 14m 30s UT. The duration of the event was about 150 milliseconds.

scholarly journals High Time Resolution Photometry of Red Dwarf Flare Stars I. A Search For Fine Structures on the Optical Light Curves of Flares

1989 ◽  
Vol 104 (2) ◽  
pp. 95-97
Author(s):  
G.M. Beskin ◽  
S.N. Mitronova ◽  
S.I. Neizvestnyj ◽  
V.L. Plakhotnichenko ◽  
L.A. Pustil'nik ◽  
...  
Keyword(s):  
Detailed Analysis ◽  
Time Scales ◽  
Time Resolution ◽  
Light Curves ◽  
High Time ◽  
Special Astrophysical Observatory ◽  
High Time Resolution ◽  
Fine Structures ◽  
Flare Stars

AbstractA detailed analysis of 73 flares on UV Cet type stars observed at the 6 m telescope of the Special Astrophysical Observatory with 3x10–7 s time resolution shows no fine structures on flare light curves with time scales from 10–6 to 10–1 s.

scholarly journals High Time Resolution Photometry of Red Dwarf Flare Stars II. The Shortest Flare Rise Time

1989 ◽  
Vol 104 (2) ◽  
pp. 99-101
Author(s):  
G.M. Beskin ◽  
V.L. Plakhotnichenko ◽  
L.A. Pustil'nik ◽  
V.F. Shvartsman ◽  
R.E. Gershberg
Keyword(s):  
Time Resolution ◽  
Rise Time ◽  
Total Duration ◽  
High Time ◽  
High Time Resolution ◽  
Gas Dynamic ◽  
Flare Stars ◽  
Flare Model

AbstractWe have studied the initial phases of 65 optical flares on UV Cet type stars with a time resolution of 3x10–7 s. Ninety per cent of these flares have rapid brightenings shorter than 10 s and several are shorter than 1 s. We detected on UV Cet the shortest flare observed to date with a total duration of 1.7 s and a rise time of 0.3 s. The shortest flare rise times on the observed stars fit the predictions of the gas-dynamic flare model by Katsova et al. (1981) and Katsova and Livshits 1986).

scholarly journals Flare Stars in Stellar Aggregates

1977 ◽  
Vol 42 ◽  
pp. 106-119
Author(s):  
L.V. Mirzoyan
Keyword(s):  
Time Resolution ◽  
Physical Nature ◽  
High Time ◽  
Optical Observations ◽  
Evolutionary Significance ◽  
High Time Resolution ◽  
Radio Observations ◽  
Stellar Flares ◽  
Flare Stars

After the report on flare stars presented by Ambartsumian and the author (1971) at the last Bamberg Colloquium, some success has been achieved in the study of these interesting objects.Optical observations of stellar flares with high time-resolution undoubtedly proved the explosive character of this phenomenon and the non-thermal nature of the radiation that appears at least at the beginning of the flare. Parallel optical and radio observations of flares in stellar aggregates complicated the interpretation and showed how far we are from an understanding of the physical nature of this phenomenon. Finally, new optical observations of stellar flares in aggregates of different age confirmed the evolutionary significance of this stage in the life of a star and led to the study of certain regularities in the evolution of flare stars.

scholarly journals High Time Resolution Photometry of Red Dwarf Flare Stars III. The Most Rapid and Faintest Observed Stellar Flares; their Physics and Statistics

1989 ◽  
Vol 104 (2) ◽  
pp. 103-105
Author(s):  
G.M. Beskin ◽  
S.I. Neizvestnyj ◽  
V.L. Plakhotnichenko ◽  
L.A. Pustil'nik ◽  
V.F. Shvartsman ◽  
...  
Keyword(s):  
Time Scales ◽  
Time Resolution ◽  
Total Duration ◽  
High Time ◽  
Energy Output ◽  
Total Power ◽  
High Time Resolution ◽  
Upper Limit ◽  
Stellar Flares ◽  
Flare Stars

AbstractHigh time resolution monitoring of the UV Cet type flare stars has enabled as to detect flares with total duration of a few seconds and with energy output comparable to solar subflares. We find that the time scales of decay for such flares correspond to recombination times of optically thin gas or to cooling times of optically thick gas heated in flares. Therefore, faster flares cannot be detected individually but their accumulated effect may be one source of brightness fluctuations of the “quiet” star. The upper limit for the total power of such microflares does not exceed the time-averaged power of individually detected flares.

Solar Corona Investigation by the Coronal Line Photometer at Lomnický Peak

1994 ◽  
Vol 144 ◽  
pp. 431-434
Author(s):  
M. Minarovjech ◽  
M. Rybanský
Keyword(s):  
Solar Corona ◽  
Time Resolution ◽  
Active Regions ◽  
High Time ◽  
High Time Resolution ◽  
List Type ◽  
Type Number ◽  
Coronal Line ◽  
Global Cycle

AbstractThis paper deals with a possibility to use the ground-based method of observation in order to solve basic problems connected with the solar corona research. Namely:1.heating of the solar corona2.course of the global cycle in the corona3.rotation of the solar corona and development of active regions.There is stressed a possibility of high-time resolution of the coronal line photometer at Lomnický Peak coronal station, and use of the latter to obtain crucial observations.

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