Zvaigznes BS17569-0011 absorbcijas spektra modelēšana
Date
2014
Authors
Aberfelds, Artis
Journal Title
Journal ISSN
Volume Title
Publisher
Latvijas Universitāte
Abstract
Veikta zvaigznes BS17569–0011 analīze izmantojot augstas izšķirtspējas absorbcijas spektru un atmosfēru modeļu metodi. Literatūrā zvaigzne klasificēta kā Galaktikas vecākās paaudzes zvaigzne ar ļoti zemu metālu koncentrāciju atmosfērā un anomālu enerģijas sadalījumu spektrā. Veikta zvaigznes integrālā starojuma analīze un konstatēts mainīgums ar dominējošo periodu, P ~ 50–75 dienas. BS17569–0011 spektrā tika identificētas ļoti intensīvas TiO molekulas absorbcijas līnijas, kas liecina par oglekļa un skābekļa attiecību C/O < 1, un emisija Balmera H un H līnijās, kas norāda uz masas zaudēšanas procesiem. Darbā noteikts zvaigznes masas centra radiālais ātrums, precizēta efektīvā temperatūra, virsmas gravitācija, mikroturbulences ātrums un aprēķināta 23 ķīmisko elementu koncentrācijas atmosfērā. Aprēķinātie atmosfēras parametri ir raksturīgi aukstajām zvaigznēm ar plašām un retinātām atmosfērām, Teff = 3300 K, log(g) = 0.0 (cgs), = 3.0 km/s.
During this scientific work star’s BS17569-0011 analysis was performed using absorption spectrum and atmospheric model method. Available data classifies it as a older generation star with very low metal abundance in the atmosphere and anomalous spectral energy distribution. Stars integral radiation analysis shows variability with a characteristic period P ~ 50-90 days. BS17569 – 0011 spectrum analysis identified intense TiO lines suggesting that carbon and oxygen ratio is C/O < 1, and Balmer H and H lines emission indicate a mass loss process. Extracted data shows star’s mass center radial velocity, clarifies atmospheric effective temperature, surface gravity, microturbulent velocity and abundances of twenty chemical elements. Atmospheric parameters are typical of very cold stars with wide and tenuous atmospheres, Teff = 3300 K, log (g) = 0.0 (cgs), = 3.0 km / s. Model calculations shows that iron group elements abundance in studied star`s atmosphere is average 4 times lower.
During this scientific work star’s BS17569-0011 analysis was performed using absorption spectrum and atmospheric model method. Available data classifies it as a older generation star with very low metal abundance in the atmosphere and anomalous spectral energy distribution. Stars integral radiation analysis shows variability with a characteristic period P ~ 50-90 days. BS17569 – 0011 spectrum analysis identified intense TiO lines suggesting that carbon and oxygen ratio is C/O < 1, and Balmer H and H lines emission indicate a mass loss process. Extracted data shows star’s mass center radial velocity, clarifies atmospheric effective temperature, surface gravity, microturbulent velocity and abundances of twenty chemical elements. Atmospheric parameters are typical of very cold stars with wide and tenuous atmospheres, Teff = 3300 K, log (g) = 0.0 (cgs), = 3.0 km / s. Model calculations shows that iron group elements abundance in studied star`s atmosphere is average 4 times lower.
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