The H alpha line emission of the Be star beta Psc: the last 40 yr

Autor(es)

Levenhagen, Ronaldo S. ^[1] ; Diaz, Marcos P. ^[2] ; Amores, Eduardo B. ^[3] ; Leister, V, Nelson

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Dept Fis, Rua Prof Artur Riedel 275, BR-09972270 Diadema, SP - Brazil

^[2] V, Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Rua Matao 1226, BR-05508900 Sao Paulo, SP - Brazil

^[3] Univ Estadual Feira de Santana UEFS, Dept Fis, Av Transnordestina S-N, BR-44036900 Feira De Santana, BA - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Monthly Notices of the Royal Astronomical Society; v. 501, n. 1, p. 747-755, FEB 2021.
• Citações Web of Science: 0

Resumo

A study on the photosphere and disc of the Be star beta Psc is presented. We recover almost 40 yr of high-resolution spectroscopic observations and additional data gathered from the BeSS data base. We evaluate the photospheric parameters from the spectral energy distribution (SED) and fittings of state-of-the-art non-LTE model atmospheres to observed helium, carbon, silicon, and magnesium line profiles. Our models include the stellar geometric deformation as well as the co-latitude dependence of temperature and gravity, aiming to derive the effects of rotation on the stellar parameters. We estimate the circumstellar disc parameters from the fitting of models assuming different disc properties, namely its radius and gas density profile. The disc inclination angle i is constrained from the fittings of He I 4471 angstrom, MgII 4481 angstrom, CII 4267 angstrom, and Si II 4128, 4132 angstrom lines with gravity darkened models. Our findings, based on model fittings, suggest that during the last 40 yr, the disc radius changed within the interval 5.5 <= R-d <= 7.8 R/R-{*}, the disc base gas density within 5 x 10(-13) <= rho <= 1 x 10(-12) g cm(-3), while the radial power-law density index m assumed values between 2.0 and 2.3. These results are in agreement with recent works dealing with spectroscopic and interferometric measurements of this object. (AU)

• Processo FAPESP: 98/10138-8 - Espectroscopia de média e alta resolução: abundâncias químicas e populações estelares
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