2024-03-29T07:41:09Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1675332022-09-27T10:26:24Zcom_10261_97com_10261_4col_10261_350
Photometric and spectroscopic variability of the B5IIIe star HD 171219
Andrade, L.
Janot-Pacheco, Eduardo
Emilio, M.
Frémat, Y.
Neiner, C.
Poretti, E.
Mathias, P.
Rainer, M.
Suárez Yanes, Juan Carlos
Uytterhoeven, K.
Briquet, M.
Diago, P.D.
Fabregat, J.
Gutiérrez-Soto, J.
European Commission
Sao Paulo Research Foundation
Ministerio de Economía y Competitividad (España)
Stars: emission-line, Be
Stars: individual: HD 171219
Stars: oscillationsStars: rotation
Stars: early-type
We analyzed the star HD 171219, one of the relatively bright Be stars observed in the seismo field of the CoRoT satellite, in order to determine its physical and pulsation characteristics. Classical Be stars are main-sequence objects of mainly B-type, whose spectra show, or have shown at some epoch, Balmer lines in emission and an infrared excess. Both characteristics are attributed to an equatorially concentrated circumstellar disk fed by non-periodic mass-loss episodes (outbursts). Be stars often show nonradial pulsation gravity modes and, as more recently discovered, stochastically excited oscillations. Applying the CLEANEST algorithm to the high-cadence and highly photometrically precise measurements of the HD 171219 light curve led us to perform an unprecedented detailed analysis of its nonradial pulsations. Tens of frequencies have been detected in the object compatible with nonradial g-modes. Additional high-resolution ground-based spectroscopic observations were obtained at La Silla (HARPS) and Haute Provence (SOPHIE) observatories during the month preceding CoRoT observations. Additional information was obtained from low-resolution spectra from the BeSS database. From spectral line fitting we determined physical parameters of the star, which is seen equator-on (i = 90°). We also found in the ground data the same frequencies as in CoRoT data. Additionally, we analyzed the circumstellar activity through the traditional method of violet to red emission Hα line variation. A quintuplet was identified at approximately 1.113 c d (12.88 μHz) with a separation of 0.017 c d that can be attributed to a pulsation degree 2. The light curve shows six small- to medium-scale outbursts during the CoRoT observations. The intensity of the main frequencies varies after each outburst, suggesting a possible correlation between the nonradial pulsations regime and the feeding of the envelope.© 2017 ESO.
This work was supported in Brazil by FAPESP (project 2008/57866), CNPq (projects 312581/2013-0 and 312738/2013-7) and CAPES (PNPD scholarship). E.P. acknowledges financial support from PRIN INAF 2014. M.R. acknowledges financial support from the FP7-Space project SpaceInn. J.C.S. acknowledges funding support from Spanish public funds for research under project ESP2015-65712-C5-5-R (MINECO/FEDER), and under Research Fellowship program >Ramon y Cajal> (MINECO/FEDER).
Peer Reviewed
2018-07-11T06:27:41Z
2018-07-11T06:27:41Z
2017
2018-07-11T06:27:42Z
artículo
http://purl.org/coar/resource_type/c_6501
doi: 10.1051/0004-6361/201629177
issn: 1432-0746
Astronomy and Astrophysics 603: A41 (2017)
http://hdl.handle.net/10261/167533
10.1051/0004-6361/201629177
http://dx.doi.org/10.13039/501100000780
http://dx.doi.org/10.13039/501100003329
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info:eu-repo/grantAgreement/EC/FP7/312844
info:eu-repo/grantAgreement/MINECO/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/ESP2015-65712-C5-5-R
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