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http://hdl.handle.net/20.500.12386/24877
DC Field | Value | Language |
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dc.contributor.author | Drazdauskas, Arnas | en_US |
dc.contributor.author | Tautvaišienė, Gražina | en_US |
dc.contributor.author | RANDICH, Maria Sofia | en_US |
dc.contributor.author | BRAGAGLIA, Angela | en_US |
dc.contributor.author | Mikolaitis, Šarūnas | en_US |
dc.contributor.author | Janulis, Rimvydas | en_US |
dc.date.accessioned | 2020-05-15T13:59:19Z | - |
dc.date.available | 2020-05-15T13:59:19Z | - |
dc.date.issued | 2016 | en_US |
dc.identifier.issn | 0004-6361 | en_US |
dc.identifier.uri | http://hdl.handle.net/20.500.12386/24877 | - |
dc.description.abstract | Context. Determining carbon and nitrogen abundances in red giants provides useful diagnostics to test mixing processes in stellar atmospheres. Aims: Our main aim is to determine carbon-to-nitrogen and carbon isotope ratios for evolved giants in the open clusters Collinder 261 and Melotte 66 and to compare the results with predictions of theoretical models. Methods: High-resolution spectra were analysed using a differential model atmosphere method. Abundances of carbon were derived using the C2Swan (0, 1) band head at 5635.5 Å. The wavelength interval 7940-8130 Å, which contains CN features, was analysed to determine nitrogen abundances and carbon isotope ratios. The oxygen abundances were determined from the [O I] line at 6300 Å. <BR /> Results: The mean values of the elemental abundances in Collinder 261, as determined from seven stars, are: [ C/Fe ] = -0.23 ± 0.02 (s.d.), [ N/Fe ] = 0.18 ± 0.09, [ O/Fe ] = -0.03 ± 0.07. The mean <SUP>12</SUP>C /<SUP>13</SUP>C ratio is 11 ± 2, considering four red clump stars and 18 for one star above the clump. The mean C/N ratios are 1.60 ± 0.30 and 1.74, respectively. For the five stars in Melotte 66 we obtained: [ C/Fe ] = -0.21 ± 0.07 (s.d.), [ N/Fe ] = 0.17 ± 0.07, [ O/Fe ] = 0.16 ± 0.04. The <SUP>12</SUP>C /<SUP>13</SUP>C and C/N ratios are 8 ± 2 and 1.67 ± 0.21, respectively. Conclusions: The <SUP>12</SUP>C /<SUP>13</SUP>C and C/N ratios of stars in the investigated open clusters were compared with the ratios predicted by stellar evolution models. The mean values of <SUP>12</SUP>C /<SUP>13</SUP>C ratios in Collinder 261 and Melotte 66 agree well with models of thermohaline-induced extra-mixing for the corresponding stellar turn-off masses of about 1.1-1.2 M<SUB>☉</SUB>. The mean C/N ratios are not decreased as much as predicted by the model in which the thermohaline- and rotation-induced extra-mixing act together. Based on observations collected at ESO telescopes under Guaranteed Time Observation programmes 071.D-0065, 072.D-0019, and 076.D-0220. | en_US |
dc.language.iso | eng | en_US |
dc.title | The extent of mixing in stellar interiors: the open clusters Collinder 261 and Melotte 66 | en_US |
dc.type | Article | - |
dc.identifier.doi | 10.1051/0004-6361/201628138 | en_US |
dc.identifier.scopus | 2-s2.0-84964755832 | en_US |
dc.identifier.isi | 000375318300062 | en_US |
dc.identifier.url | https://www.aanda.org/articles/aa/abs/2016/05/aa28138-16/aa28138-16.html | en_US |
dc.relation.medium | STAMPA | en_US |
dc.relation.volume | 589 | en_US |
dc.relation.firstpage | A50 | en_US |
dc.type.referee | REF_1 | en_US |
dc.description.international | sì | en_US |
dc.relation.scientificsector | FIS/05 - ASTRONOMIA E ASTROFISICA | en_US |
dc.relation.journal | ASTRONOMY & ASTROPHYSICS | en_US |
dc.type.miur | 262 Articolo in rivista | - |
dc.identifier.adsbibcode | 2016A&A...589A..50D | en_US |
dc.relation.ercsector | ERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation | en_US |
dc.description.apc | no | en_US |
dc.description.oa | 1 – prodotto con file in versione Open Access (allegare il file al passo 5-Carica) | en_US |
item.grantfulltext | open | - |
item.cerifentitytype | Publications | - |
item.openairetype | Article | - |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.fulltext | With Fulltext | - |
item.languageiso639-1 | en | - |
crisitem.journal.journalissn | 0004-6361 | - |
crisitem.journal.ance | E016240 | - |
crisitem.author.dept | O.A. Arcetri | - |
crisitem.author.dept | OAS Bologna | - |
crisitem.author.orcid | 0000-0003-2438-0899 | - |
crisitem.author.orcid | 0000-0002-0338-7883 | - |
Appears in Collections: | 1.01 Articoli in rivista |
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aa28138-16.pdf | PDF editoriale | 828.58 kB | Adobe PDF | View/Open |
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