Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/29680
DC Field | Value | Language |
---|---|---|
dc.contributor.author | Ibañez Bustos, R. V. | en_US |
dc.contributor.author | Buccino, A. P. | en_US |
dc.contributor.author | Messina, S. | en_US |
dc.contributor.author | LANZA, Antonino Francesco | en_US |
dc.contributor.author | Mauas, P. J. D. | en_US |
dc.date.accessioned | 2021-01-12T08:27:19Z | - |
dc.date.available | 2021-01-12T08:27:19Z | - |
dc.date.issued | 2020 | en_US |
dc.identifier.issn | 0004-6361 | en_US |
dc.identifier.uri | http://hdl.handle.net/20.500.12386/29680 | - |
dc.description.abstract | Recently, new debates about the role of layers of strong shear have emerged in stellar dynamo theory. Further information on the long-term magnetic activity of fully convective stars could help determine whether their underlying dynamo could sustain activity cycles similar to the solar one. We performed a thorough study of the short- and long-term magnetic activity of the young active dM4 star Gl 729. First, we analyzed long-cadence $K2$ photometry to characterize its transient events (e.g., flares) and global and surface differential rotation. Then, from the Mount Wilson $S$-indexes derived from CASLEO spectra and other public observations, we analyzed its long-term activity between 1998 and 2020 with four different time-domain techniques to detect cyclic patterns. Finally, we explored the chromospheric activity at different heights with simultaneous measurements of the H$\alpha$ and the Na I D indexes, and we analyzed their relations with the $S$-Index. We found that the cumulative flare frequency follows a power-law distribution with slope $\sim- 0.73$ for the range $10^{32}$ to $10^{34}$ erg. We obtained $P_{rot} = (2.848 \pm 0.001)$ days, and we found no evidence of differential rotation. We also found that this young active star presents a long-term activity cycle with a length of $\text{about four}$ years; there is less significant evidence of a shorter cycle of $0.8$ year. The star also shows a broad activity minimum between 1998 and 2004. We found a correlation between the S index, on the one hand, and the H$\alpha$ the Na I D indexes, on the other hand, although the saturation level of these last two indexes is not observed in the Ca lines. Because the maximum-entropy spot model does not reflect migration between active longitudes, this activity cycle cannot be explained by a solar-type dynamo. It is probably caused by an $\alpha^2$-dynamo. | en_US |
dc.language.iso | eng | en_US |
dc.title | Activity-rotation in the dM4 star Gl 729. A possible chromospheric cycle | en_US |
dc.type | Article | - |
dc.identifier.doi | 10.1051/0004-6361/202039164 | en_US |
dc.identifier.scopus | 2-s2.0-85097009386 | en_US |
dc.identifier.isi | 000595814100002 | en_US |
dc.identifier.url | https://www.aanda.org/articles/aa/abs/2020/12/aa39164-20/aa39164-20.html | en_US |
dc.identifier.url | https://ui.adsabs.harvard.edu/abs/2020A%26A...644A...2I/abstract | en_US |
dc.relation.medium | STAMPA | en_US |
dc.relation.volume | 644 | en_US |
dc.relation.issue | A2 | en_US |
dc.relation.firstpage | 1 | en_US |
dc.relation.lastpage | 14 | en_US |
dc.relation.numberofpages | 14 | en_US |
dc.type.referee | REF_1 | en_US |
dc.description.numberofauthors | 5 | 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 | 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::PE9_6 Stars and stellar systems | 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.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.openairetype | Article | - |
item.languageiso639-1 | en | - |
item.cerifentitytype | Publications | - |
item.grantfulltext | open | - |
item.fulltext | With Fulltext | - |
crisitem.author.dept | O.A. Catania | - |
crisitem.author.dept | O.A. Catania | - |
crisitem.author.orcid | 0000-0002-2851-2468 | - |
crisitem.author.orcid | 0000-0001-5928-7251 | - |
crisitem.journal.journalissn | 0004-6361 | - |
crisitem.journal.ance | E016240 | - |
Appears in Collections: | 1.01 Articoli in rivista |
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File | Description | Size | Format | |
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aa39164-20.pdf | PDF editoriale | 3.85 MB | Adobe PDF | View/Open |
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