The system for registration of star brightness fast variations
Abstract
A new system of electro photometer in conjunction with a computer is proposed which permits to register fast variations of the brightness of the observed stars in the case of small integration time (1-0.001 sec) without using a large amount of recording paper, magnetic tape, etc., which is usual for such observations. The principle of the proposed method is the following. The output of the photon counting electro photometer is given to a computer (of the "Electronica 60" type), which at a given time interval (say, 100 or more counts) determines the mean value of the signal of the observed star. If each following count doesn't differ from this mean value by more than mσ (the value of m maybe 3, as usual, or more, it depends on the observer), nothing is being registered. But when the signal exceeds say by 3σ the mean value determined at the preceding time interval, all following counts are transferred to the computer memory and then are registered. The electro photometer operating in a proposed mode has been tested in the laboratory and then in the observations of stars, with the 40 cm telescope of the Byurakan Observatory. During 50 hours of observations of standard stars, no flare has been recorded. No flare has been recorded also during 55 years observations of the flare stars AD Leo, Wolf 630, BY Dra and V 1258 Aql. Three flares were recorded during 22 hours of observations of EV Lac. The duration of the first two flares with magnitudes of about 1m.3 was about 3 sec. The increase of the brightness of the third, more powerful flare of 2m.2, lasted about 1 sec and the decline of the brightness lasted 17 sec.
- Publication:
-
Communications of the Byurakan Astrophysical Observatory
- Pub Date:
- 1986
- Bibcode:
- 1986CoBAO..58...87Z
- Keywords:
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- Astronomical Photometry;
- Flare Stars;
- Light Curve;
- Stellar Radiation;
- Variable Stars;
- Brightness;
- Electrophotometers;
- Flow Charts;
- Signal Processing;
- Stellar Flares;
- Instrumentation and Photography