West, R.M. და ვესტი, რ. და Вест, Р.М. (1970) An investigation of the 3600-4000A region in G5-K5 stars by means of objective prism spectra of intermediate dispersion / G5-K5 ვარსკვლავთა სპექტრული უბნის 3600-4000A გამოკვლევა ობიექტივწინა პრიზმით მიღებული ზომიერი დისპერსიის სპექტრების მეშვეობით. აბასთუმნის ასტროფიზიკური ობსერვატორიის ბიულეტენი / Bulletin of the Abastumani Astrophysical Observatory (39). С. 29-83.
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ტექსტი
1970-39–4.pdf Download (12MB) | გადახედვა |
რეზიუმე
An investigation of the 3600 - 4000 A region in G and K stare (mainly giants) has been carried out by deans of 194 objective prism spectra of dispersion 110 A/mm at 3900 A. Thirty-seven lines and bands in this spectral region were identified and their depths measured relative to two different straight-line continue. Ten additional points situated on peaks between the lines were also measured. Correlation coefficients between various spectral parameters (MK spectral class, (U-B), (B-V), Mv, C, C" and [Fe/H]) and the 1081 possible line depth ratios wore computed. Then those line ratios that showed the largest correlations were selected. Finally, linear combinations of these line ratios from which the spectral parameters can be determined were established. This rather lengthy procedure implies that no major spectral criteria could possibly be overlooked and that the adopted criteria are really the beet available for the present spectra. The main result of the investigation is the establishment of a scheme for a quantitative spectral classification of the G5 - K5 stars at the present dispersion. Especially, it Is possible to determine the value of [Fe/H] for G8 - K3 giants with a mean error of 0.15. For the spectral class and the luminosity, the optimal accuracy is found to be - 1 subclass and - 1m, respectively. The colour index (R - I), being an indicator of the effective temperature. No criteria for the MK spectral class and the luminosity have been found that are definitely better than those known in the blue spectral region. The possibility of determining [Fe/H] should therefore be the main reason for using the 3600 - 4000 A region in classification work on G5 - K5 stars at this dispersion. An important result of this investigation is the possibility of determining the value of [Fe/H] for G8-K3 gaints with a mean error of 0.15. This accuracy corresponds to a class-division into three or four metal-content classes in the interval 0>[Fe/H]>-1.0. In this work the limiting U-magnitude is close to 11m.2. A large-scale investigation of the distribution of the metal content of late-type giant stars would therefore be possible on the basis of the present results.
| ობიექტის ტიპი: | სტატია |
|---|---|
| თემატიკა: | Q Science > QB Astronomy |
| ქვეგანყოფილება: | Institutes > Evgeny Kharadze Abastumani National Astrophysical Observatory |
| განმათავსებელი მომხმარებელი: | თამარ ჭაღიაშვილი |
| განთავსების თარიღი: | 25 ივლისი 2018 09:36 |
| ბოლო ცვლილება: | 25 ივლისი 2018 09:36 |
| URI: | http://eprints.iliauni.edu.ge/id/eprint/8398 |
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