Trapezium type multiple systems consisting of T Tau and flare stars in the Orion Association

Astrophysics ◽  
1988 ◽  
Vol 28 (1) ◽  
pp. 86-91
Author(s):  
V. V. Ambaryan
Keyword(s):  
Multiple Systems ◽  
Trapezium Type ◽  
Orion Association ◽  
Flare Stars ◽  
T Tau

scholarly journals Young and Old Subsystems of Flare Stars

1995 ◽  
Vol 151 ◽  
pp. 63-64
Author(s):  
L.V. Mirzoyan ◽  
V.V. Hambarian
Keyword(s):  
Evolutionary Status ◽  
Wide Field ◽  
Flare Activity ◽  
Multiple Systems ◽  
Star Evolution ◽  
Orion Association ◽  
Evolutionary Connection ◽  
Long Time ◽  
Flare Stars ◽  
T Tau

Photographic observations with wide-field telescopes of flare stars in the Orion association and the Pleiades cluster have been carried out since 40 years. About 500 flare stars were found in each of these systems. The ages of these stellar systems differ by one or two orders of magnitude (Mirzoyan 1991). This fact allows us to compare them, in order to show that they fit into the concept, suggested first by Haro (1957), that the evolutionary status of flare stars is a stage of red dwarf star evolution which follows that of the T Tau stars (Haro 1976, Ambartsumian & Mirzoyan 1970).The basic difference between the Orion and Pleiades subsystems of flare stars has been known for a long time: the coexistence of flare stars and T Tau stars in the Orion association, and the absence of the latter group in the Pleiades. Some of the T Tau stars show flare activity (Haro 1964). This fact and the existence of multiple systems of trapezium type, which are dynamically unstable, in the Orion association, are arguments in favour of an evolutionary connection between these two types of stars.

scholarly journals A Search for Trapezium Type Multiple Systems in T-Associations

1983 ◽  
Vol 62 ◽  
pp. 52-56
Author(s):  
G. N. Salukvadze
Keyword(s):  
Variable Stars ◽  
Multiple Systems ◽  
Trapezium Type ◽  
Multiple Stars ◽  
Wide Pairs ◽  
Double And Multiple Stars ◽  
Type Variable ◽  
T Tau

A high percentage of double and multiple stars among those in T-associations was first paid attention to by Prof V.A. Ambartsumian. Further at the beginning of sixties many investigators of variable stars (Kukarkin, Herbig et al.) paid attention to the necessity of studying duplicity of stars in T-associations. Just then the first lists of wide pairs in T-associations appeared.We set a task to search for the Trapezium type multiple stars in T-associations involving the groupings of T Tau type variable stars from Kholopov’s list at a distance up to 500 pc. Such associations proved to amount 19, but out of them we succeeded in searching only in 12 ones.

scholarly journals Double-Peaked Flare Events on red Dwarf Stars and Solar ‘Sympathetic’ Flares

1976 ◽  
Vol 71 ◽  
pp. 475-475
Author(s):  
M. Rodonò
Keyword(s):  
Proximity Effect ◽  
Binary Systems ◽  
Angular Separation ◽  
Dwarf Stars ◽  
Multiple Systems ◽  
Photometric Observations ◽  
Red Dwarfs ◽  
Flare Stars ◽  
Red Dwarf Stars ◽  
The Individual

About 50% of the flare events observed on red dwarfs are at least double-peaked. As the majority of flare stars are members of double or multiple systems, the possibility that time-overlapping flares originate quasi-simultaneously on the individual components is discussed.Assuming a poissonian occurrence of flares in both components, the expected probability of observing double-peaked flares is lower than 1% for the most active binary systems.However, from photometric observations of the double flare star EQ Peg (BD +19°5116 AB) carried out by the author with an area scanner (the components' angular separation is 3.7″) about 20% of the observed flares have been found to be double-peaked flares resulting from separate flares, one in each component. A direct flare triggering of the following flare by the preceding one can be ruled out since the light travel-time between the two components is 3.5 h, while the observed time delay between the flare peaks is about 10 min. Moreover, the proximity effect does not seem to play an important triggering role.It is concluded that, although the analogy with solar ‘sympathetic’ flares is not always applicable, it is the most promising framework within which the majority of double-peaked flare events on red dwarfs must be interpreted.

scholarly journals The Red Dwarf Star Population in the Galaxy

1995 ◽  
Vol 151 ◽  
pp. 55-56 ◽  
Author(s):  
L.V. Mirzoyan
Keyword(s):  
Star Clusters ◽  
Space Distribution ◽  
Dwarf Star ◽  
Star Clusters And Associations ◽  
Dwarf Stars ◽  
The Galaxy ◽  
Flare Stars ◽  
Red Dwarf Stars ◽  
T Tau ◽  
Stellar Associations

Red dwarf stars in the Galaxy occur in three forms: as flare stars, T Tau stars and red dwarf stars of constant brightness. Haro (1957) suggested that all these stars present regular evolutionary stages of red dwarf stars.The space distribution of UV Cet flare stars in the solar vicinity indicates that these low luminosity stars belong to the disk population of the Galaxy. Therefore one can suppose that all red dwarf stars have a space distribution which is similar to that of the flare stars (Mirzoyan et al. 1988a). Only a small part of them is found in star clusters and associations. The T Tau stars are an exception: because of their very short lifetime, all of them are found in stellar associations.The space distribution of red dwarf stars is determined by the fact that all of them are formed in star clusters and associations and are finally lost from their stellar systems and merge into the general galactic field (Mirzoyan 1995).

scholarly journals An automatic search for flare stars in southern stellar aggregates of different ages

1990 ◽  
Vol 137 ◽  
pp. 85-94
Author(s):  
R. Aniol ◽  
H. W. Duerbeck ◽  
W.C. Seitter ◽  
M.K. Tsvetkov
Keyword(s):  
Stellar Mass ◽  
Astronomical Institute ◽  
European Southern Observatory ◽  
Orion Association ◽  
Different Ages ◽  
First Results ◽  
Automatic Search ◽  
Flare Stars

Statistically relevant samples of flare stars in stellar aggregates can be used to specify the stellar mass-age-activity-relation when the ages of the aggregates are known from independent investigations. Associations and clusters of the southern sky are currently surveyed with the GPO astrograph of the European Southern Observatory. The plates are digitized with the PDS 2020 GMplus microdensitometer and the data are reduced automatically at the Astronomical Institute of Muenster University. The programme package “FLARE” is described. First results from the Orion association are presented.

scholarly journals Some Physical Parameters and uv by β Photometry of Trapezium Type Multiple Systems

1995 ◽  
Vol 164 ◽  
pp. 378-378
Author(s):  
G.N. Salukvadze ◽  
G.Sh. Javakhishvili
Keyword(s):  
Physical Parameters ◽  
Photometric System ◽  
Multiple Systems ◽  
Trapezium Type

The present paper deals with the results of electrophotometric observations of 59 components of 19 trapezia in the Stroemgren and Crawford six-colour photometric system.

scholarly journals Subfuors in Orion association

1990 ◽  
Vol 137 ◽  
pp. 253-256
Author(s):  
L.G. Gasparian ◽  
A.S. Melkonian ◽  
G.B. Ohanian ◽  
E.S. Parsamian
Keyword(s):  
Emission Lines ◽  
Absorption Bands ◽  
Photometric Observations ◽  
Orion Association ◽  
T Tau Type Stars ◽  
T Tau

Results of spectral and photometric observations of Sugano star = V1143 Ori in brightness minimum and near it are given. Emission lines of HI, CaII, FeI, TiI, TiII and TiO absorption bands are detected. The appearing envelope is observed also in minimum. A brightness increase of Shanalstar V1118 Ori is observed. In its spectrum lines of HI, CaII, FeI, FeII are found, testifying to formation of an envelope.During the last ten years data on T Tau type stars which have fuor-like outburst-subfuors were obtained. Two such stars were found in Orion association. These are V1118 Ori [1] and V 1143 Ori [2,3]. In recent years, in Byurakan observatory observations of these stars have been made.

scholarly journals Flare Star Observations in the Praesepe Region

1977 ◽  
Vol 42 ◽  
pp. 120-125
Author(s):  
I. Jankovics
Keyword(s):  
Observational Data ◽  
Flare Star ◽  
Flare Activity ◽  
List Type ◽  
The Sun ◽  
Type Number ◽  
Orion Association ◽  
Order Of Magnitude ◽  
Photographic Survey ◽  
Flare Stars

In a program of systematic search for flare stars in clusters and associations we have carried out a photographic survey in the region of Praesepe. The previously obtained interesting results in the Pleiades cluster and the Orion association stimulated us to continue the work of Haro (1968) and Rosino (1966) in Praesepe. The importance of observations in this cluster is obvious if we consider the following circumstances: 1. Praesepe and Pleiades have nearly the same distance from the Sun, 160 and 125 pc, respectively.2. There exists a difference in age between the 2 clusters of at least one order of magnitude.3. The use of Schmidt telescopes allows observations in large cluster regions.A great number of observational data are desirable for comparison of flare activity in the regions of Pleiades and Praesepe.

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