0000000001180772
AUTHOR
F. Baudin
The B0.5IVe CoRoT target HD 49330. I. Photometric analysis from CoRoT data
International audience; Context: Be stars undergo outbursts producing a circumstellar disk from the ejected material. The beating of non-radial pulsations has been put forward as a possible mechanism of ejection. Aims: We analyze the pulsational behavior of the early B0.5IVe star HD 49330 observed during the first CoRoT long run towards the Galactical anticenter (LRA1). This Be star is located close to the lower edge of the beta Cephei instability strip in the HR diagram and showed a 0.03 mag outburst during the CoRoT observations. It is thus an ideal case for testing the aforementioned hypothesis. Methods: We analyze the CoRoT light curve of HD 49330 using Fourier methods and non-linear le…
The B0.5IVe CoRoT target HD 49 330. I. Photometric analysis from CoRoT data
Context. Be stars undergo outbursts producing a circumstellar disk from the ejected material. The beating of non-radial pulsations has been put forward as a possible mechanism of ejection. Aims. We analyze the pulsational behavior of the early B0.5IVe star HD 49330 observed during the first CoRoT long run towards the Galactical anticenter (LRA1). This Be star is located close to the lower edge of the β Cephei instability strip in the HR diagram and showed a 0.03 mag outburst during the CoRoT observations. It is thus an ideal case for testing the aforementioned hypothesis. Methods. We analyze the CoRoT light curve of HD 49330 usin g Fourier methods and non-lin ear least square fitting. Resul…
Normal values for fundus perimetry with the MAIA microperimeter and short-term repeatability evaluation
National audience; Purpose To assess retinal sensitivity by means of microperimetry and to evaluate the intersession fluctuation using the MAIA microperimeter in healthy volunteers. Methods Prospective, monocentre study. Fifty‐six healthy volunteers (age range, 20–80 years), underwent an automatic, full‐threshold microperimetry of the central field (custom grid, area of 10° in diameter, 37 stimulated points), with the MAIA microperimeter (CenterVue, Padova, Italy). A subgroup of 24 subjects was retested after 1 h (test 2) and 1 week (test 3) to determine the repeatability of the technique. A subgroup of 22 subjects was also tested on the OPKO microperimeter (Optos, Dunfermline, Scotland) (a…
The pulsations of the B5IVe star HD 181 231 observed with CoRoT and ground-based spectroscopy
Context. HD 181231 is a B5IVe star, which has been observed with the CoRoT satellite during ∼5 consecutive months and simultaneously from the ground in spectroscopy and spectropolarimetry. Aims. By analysing these data, we aim to detect and characterize as many pulsation frequencies as possible, to search for the presence of beating effects possibly at the origin of the Be phenomenon. Our results will also pr ovide a basis for seismic modelling. Methods. The fundamental parameters of the star are determined from spectral fitting and from the study of the circumstellar emission. The CoRoT photometric data and ground-based spectroscopy are analysed using several Fourier Techniques: CLEAN-NG,P…
Pulsations of HD 181231
HD181231 is a B5IVe star, which has been observed with the CoRoT satellite during ~5 consecutive months and simultaneously from the ground in spectroscopy and spectropolarimetry. By analysing these data, we aim to detect and characterize as many pulsation frequencies as possible, to search for the presence of beating effects possibly at the origin of the Be phenomenon. Our results will also provide a basis for seismic modelling. The fundamental parameters of the star are determined from spectral fitting and from the study of the circumstellar emission. The CoRoT photometric data and ground-based spectroscopy are analysed using several Fourier techniques: Clean-ng, Pasper, and Tisaft, as wel…
Fourier analysis of HD 49330 CoRoT light curve
Be stars undergo outbursts producing a circumstellar disk from the ejected material. The beating of non-radial pulsations has been put forward as a possible mechanism of ejection. We analyze the pulsational behavior of the early B0.5IVe star HD 49330 observed during the first CoRoT long run towards the Galactical anticenter (LRA1). This Be star is located close to the lower edge of the {beta} Cephei instability strip in the HR diagram and showed a 0.03mag outburst during the CoRoT observations. It is thus an ideal case for testing the aforementioned hypothesis.