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Campo DC | Valor | Idioma |
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dc.rights.license | © ESO 2021 | es |
dc.contributor.author | Eiroa, C. | - |
dc.contributor.author | Montesinos, B. | - |
dc.contributor.author | Rebollido, I. | - |
dc.contributor.author | Henning, T. | - |
dc.contributor.author | Launhardt, R. | - |
dc.contributor.author | Maldonado, J. | - |
dc.contributor.author | Meeus, G. | - |
dc.contributor.author | Mora, A. | - |
dc.contributor.author | Rivière Marichalar, P. | - |
dc.contributor.author | Villaver, E. | - |
dc.contributor.other | Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737 | - |
dc.date.accessioned | 2022-04-08T08:40:42Z | - |
dc.date.available | 2022-04-08T08:40:42Z | - |
dc.date.issued | 2021-09-21 | - |
dc.identifier.citation | Astronomy and Astrophysics 653: A115(2021) | es |
dc.identifier.issn | 0004-6361 | - |
dc.identifier.other | https://www.aanda.org/articles/aa/full_html/2021/09/aa41140-21/aa41140-21.html | - |
dc.identifier.uri | http://hdl.handle.net/20.500.12666/730 | - |
dc.description | A copy of the spectra and Table C.1 are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/653/A115 Part of this work was made while at the Departamento de Física Teórica of the Universidad Autónoma de Madrid, and as visiting astronomer at Calar Alto Observatory. | es |
dc.description.abstract | Context. We previously suggested that variable red- and blueshifted absorption features observed in the Ca II K line towards the A-type shell star ϕ Leo are likely due to solid, comet-like bodies in the circumstellar (CS) environment. Aims. Our aim is to expand our observational study of ϕ Leo to other characteristic spectral lines of A-type photospheres as well as to lines arising in their CS shells. Methods. We obtained more than 500 high-resolution optical spectra collected at different telescopes over 37 nights in several observing runs from December 2015 to January 2019. Consecutive time-series spectra were taken, covering intervals of up to ~9 h on some nights. We analysed some photospheric lines, in particular Ca I 4226 Å and Mg II 4481 Å, as well as the circumstellar shell lines Ca II H and K, the Ca II IR triplet, Fe II 4924, 5018, and 5169 Å, Ti II 3685, 3759, and 3761 Å, and the Balmer lines Hα and Hβ. Results. Our observational study reveals that ϕ Leo is a variable δ Scuti star whose spectra show remarkable dumps and bumps superimposed on the photospheric line profiles, which vary in strength and sharpness, propagate from blue- to more redshifted radial velocities, and persist for a few hours. Similarly to other δ Scuti stars, these features are likely produced by non-radial pulsations. At the same time, all shell lines present emission at ~3 km s−1 centred at the core of the CS features, and two variable absorption minima at both sides of the emission; those absorption minima occur at almost the same velocity for each line, that is, no apparent dynamical evolution is observed. The variations observed in the Ca II H and K, Fe II, and Ti II lines occur on a range of timescales from minutes to days and between observing runs, but without any clear correlation or recognisable temporal pattern among the different lines. In the case of Hα, the CS contribution is also variable in just one of the observing runs. Conclusions. We suggest that ϕ Leo is a rapidly rotating δ Scuti star surrounded by a variable, (nearly) edge-on CS disk possibly re-supplied by the δ Scuti pulsations. The behaviour of the CS shell lines is reminiscent of that of rapidly rotating Be shell stars with an edge-on CS disk, and is clear evidence that the variations observed in the CS features of ϕ Leo are highly unlikely to be produced by exocomets. In addition, the observational results presented in this work, together with some recent results concerning the shell star HR 10, highlight the need for critical revision of the Ca II K features, which have been attributed to exocomets in other shell stars. | es |
dc.description.sponsorship | The authors thank the referee for the comments and suggestions to the original manuscript. This work is based on observations made at the Spanish Observatorio del Roque de los Muchachos (La Palma, Spain) of the Instituto de Astrofísica de Canarias with the Mercator Telescope, operated by the Flemmish Community, the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association, and the Italian Telescopio Nazionale Galileo (TNG) operated by the Fundación Galileo Galilei of the INAF. Based on observations made with the ESO/MPG 2.2 m telescope at the La Silla Observatory under programmes 099.A-9029(A) and 094.A-9012. C.E., B.M., I.R., G.M. and E.V. were supported by Spanish grant AYA 2014-55840-P; B.M., I.R., G.M. and E.V. are also supported by Spanish grant PGC2018-101950-B-100; B.M. and E.V. are also partly funded by the Spanish State Research Agency (AEI) project No. MDM-2017-0737 Unidad de Excelencia ‘María de Maeztu’ Centro de Astrobiología (CAB, CSIC-INTA). We thank Ana Guijarro of the Calar Alto Observatory for obtaining the CARMENES spectrum. | es |
dc.language.iso | eng | es |
dc.publisher | EDP Sciences | es |
dc.relation | info:eu-repo/grantAgreement/MINECO//AYA2014-55840-P/ES/DE PIEDRAS A PLANETAS Y VUELTA A ROCAS: COMPRENDIENDO LA FORMACION Y DESTRUCCION DE PLANETAS/ | - |
dc.relation | info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PGC2018-101950-B-I00/ES/ON THE ROCKS II/ | - |
dc.rights | Attribution-NonCommercial-NoDerivatives 4.0 International | es |
dc.rights.uri | https://creativecommons.org/licenses/by-nc-nd/4.0/ | - |
dc.subject | Stars: individual: ϕ Leo | es |
dc.subject | Stars: early type | es |
dc.subject | Stars: variables: δ Scuti | es |
dc.subject | Stars: emission-line, Be | es |
dc.subject | Circumstellar matter | es |
dc.subject | Comets: general | es |
dc.title | The A-shell star ϕ Leo revisited: its photospheric and circumstellar spectra | es |
dc.type | info:eu-repo/semantics/article | es |
dc.identifier.doi | 10.1051/0004-6361/202141140 | - |
dc.identifier.e-issn | 1432-0746 | - |
dc.contributor.funder | Agencia Estatal de Investigación (AEI) | - |
dc.contributor.funder | Ministerio de Economía y Competitividad (MINECO) | - |
dc.contributor.funder | Istituto Nazionale di Astrofisica (INAF) | - |
dc.description.peerreviewed | Peerreview | es |
dc.identifier.funder | http://dx.doi.org/10.13039/501100011033 | - |
dc.identifier.funder | http://dx.doi.org/10.13039/501100003329 | - |
dc.identifier.funder | http://dx.doi.org/10.13039/501100005184 | - |
dc.type.hasVersion | info:eu-repo/semantics/publishedVersion | - |
dc.rights.accessRights | info:eu-repo/semantics/openAccess | - |
dc.type.coar | http://purl.org/coar/resource_type/c_6501 | - |
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