Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· arXiv e-print (arXiv:1003.5625)
· References in the article
· Citations to the Article (13) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (3)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Properties and nature of Be stars. 27. Orbital and recent long-term variations of the Pleiades Be star Pleione = BU Tauri
Authors:
Nemravová, J.; Harmanec, P.; Kubát, J.; Koubský, P.; Iliev, L.; Yang, S.; Ribeiro, J.; Slechta, M.; Kotková, L.; Wolf, M.; Skoda, P.
Affiliation:
AA(Astronomical Institute of the Charles University, Faculty of Mathematics and Physics, V Holesovickách 2, 180 00 Praha 8, Czech Republic ), AB(Astronomical Institute of the Charles University, Faculty of Mathematics and Physics, V Holesovickách 2, 180 00 Praha 8, Czech Republic), AC(Astronomical Institute of the Academy of Sciences, 251 65 Ondrejov, Czech Republic), AD(Astronomical Institute of the Academy of Sciences, 251 65 Ondrejov, Czech Republic), AE(Institute of Astronomy, Bulgarian Academy of Sciences, 1784, 72 Tsarigradsko Chaussee Blvd., Sofia, Bulgaria), AF(Physics and Astronomy Department, University of Victoria, PO Box 3055 STN CSC, Victoria, BC, V8W 3P6, Canada), AG(Observatório do Instituto Geográfico do Exército, R. Venezuela 29, 3 Esq. 1500-618, Lisboa, Portugal), AH(Astronomical Institute of the Academy of Sciences, 251 65 Ondrejov, Czech Republic), AI(Astronomical Institute of the Academy of Sciences, 251 65 Ondrejov, Czech Republic), AJ(Astronomical Institute of the Charles University, Faculty of Mathematics and Physics, V Holesovickách 2, 180 00 Praha 8, Czech Republic), AK(Astronomical Institute of the Academy of Sciences, 251 65 Ondrejov, Czech Republic)
Publication:
Astronomy and Astrophysics, Volume 516, id.A80, 10 pp. (A&A Homepage)
Publication Date:
06/2010
Origin:
EDP Sciences
Astronomy Keywords:
stars: early-type, binaries: close, stars: emission-line, Be, stars: individual: BU Tau
DOI:
10.1051/0004-6361/200913885
Bibliographic Code:
2010A&A...516A..80N

Abstract

Radial-velocity variations of the Halpha emission measured on the steep wings of the Halpha line, prewhitened for the long-time changes, vary periodically with a period of 218.025 ° ± 0.022°, confirming the suspected binary nature of the bright Be star BU Tau, a member of the Pleiades cluster. The orbit seems to have a high eccentricity over 0.7, but we also briefly discuss the possibility that the true orbit is circular and that the eccentricity is spurious owing to the phase-dependent effects of the circumstellar matter. The projected angular separation of the spectroscopic orbit is large enough to allow the detection of the binary with large optical interferometers, provided the magnitude difference primary - secondary is not too large. Since our data cover the onset of a new shell phase up to development of a metallic shell spectrum, we also briefly discuss the recent long-term changes. We confirm the formation of a new envelope, coexisting with the previous one, at the onset of the new shell phase. We find that the full width at half maximum of the Halpha profile has been decreasing with time for both envelopes. In this connection, we briefly discuss Hirata's hypothesis of precessing gaseous disk and possible alternative scenarios of the observed long-term changes.

Based on new spectral and photometric observations from the following observatories: Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, National Research Council of Canada, Haute Provence, IGeoE-Lisbon, Astronomical Institute AS CR Ondrejov, and Rozhen.

Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints