Gordeladse, Sh.G. და გორდელაძე, შ. და Горделадзе, Ш.Г. (1938) ახალ ვარსკვლავთა ტემპერატურის საკითხისათვის / On the temperature of Novae. აბასთუმნის ასტროფიზიკური ობსერვატორიის ბიულეტენი / Bulletin of the Abastumani Astrophysical Observatory (3). С. 103-110.
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ტექსტი
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რეზიუმე
It is known that in the first phase of the outburst the former Nova. Show a large value of temperature, while the absolute magnitude of the star remains the same is it was before the outburst. This fact is being interpreted by some authors as the result of the condensation 0f the star. On the other hand, it may be considered as certain that the effective temperature of the star remains unchanged till to the maximum. At the same time, owing to the enormous growth of the luminous surface of the star, its integral radiation augments correspondingly, the radiating capacity remaining apparently unchanged. These circumstances suggest that the source of energy which secures the constancy of the radiating capacity of the star during such a great growth of its luminous surface must be much more powerful and intensive than that, which is necessary to maintain the radiation before the outburst. Evidently, the condensation of the star, if this phenomenon were to take place during the outburst of Nova, would be possible only after the main maximum, because before it the expansion of the outer layers of the star is alone surmised. Therefore, the energy of contraction can not be considered as the above source of energy. We suppose that the inner layers of the star, which are being denuded in consequence of the separation of the outer ones and have, therefore, a higher temperature, may serve as such a source. We made an attempt to estimate approximately the order of the temperature of those denuded layers. Expressing the mass (M) of the outer layers which are separated later, by means of equation (1) and taking into account the condition (2) of the hydrostatic equilibrium we get for the value of the mass detached (M) expression (3), where r is the radius of the star, P-the gas pressure and G—the intensity of gravity. Farther, using the expression (4) given tor P by Chandrasekhar we obtain equation (5), where T is the temperature of denuded layer, T0-that of the star's surface, P0-the radiation pressure and β-the quantity, the value of which is determined by Chandrasekhar. If we make calculation for a star similar to our sun we get equation (6) front which the ratio T/T0 may be directly derived if the value of the mass detached (M) is known. Taking into account that the value of this mass (M) lies in the interval 10^25-10^26 in conformance to the absolute stellar magnitudes of Novae at maximum we may form a table or draw a curve which will show that for instance, if M=10 gr then T/T0=25, i.e. that the radiating capacity of denuded layers is 25 times as great as that of the surface layers; it corresponds approximately to the quantity of energy needed to maintain the consultancy of the radiating capacity of the star during the expansion of its luminous surface, if we assume that during the outburst the radius of the star grows about 500 times. Farther, if we consider that in the final phase of the outburst the temperature of Novae is being determined by Zanstra's method, giving under certain conditions exaggerated values of temperature, it becomes evident that accepting the point of view developed by the authr there is no necessity to suppose that the increase of temperature during the outburst is due to the condensation of the star. We must suppose, on the contrary, that the denuded layers of the stars cannot maintain a high temperature for a long time, because the inflow of energy from the inner layers must apparently remain the same as it was before the outburst, while the radiation is greatly increased in consequence of denudation. Thus, it being impossible to compensate the energy radiated by those denuded layers there last must gradually grow cooler. It would be of interest to derive the law, according to which this cooling is to take course. October, 1937
| ობიექტის ტიპი: | სტატია |
|---|---|
| თემატიკა: | Q Science > QB Astronomy |
| ქვეგანყოფილება: | Institutes > Evgeny Kharadze Abastumani National Astrophysical Observatory |
| განმათავსებელი მომხმარებელი: | თამარ ჭაღიაშვილი |
| განთავსების თარიღი: | 09 ივლისი 2018 10:23 |
| ბოლო ცვლილება: | 09 ივლისი 2018 10:23 |
| URI: | http://eprints.iliauni.edu.ge/id/eprint/8170 |
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