Issue |
A&A
Volume 374, Number 3, August II 2001
|
|
---|---|---|
Page(s) | 1100 - 1107 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361:20010780 | |
Published online | 15 August 2001 |
Spectral analysis of solar diameter measurements recorded at Calern Observatory astrolabe during two solar cycles
1
CRAAG - Observatoire d'Alger, BP 63, Bouzaréah, Alger, Algeria e-mail: irbah@unice.fr
2
Université de Nice-Sophia Antipolis, UMR n 6525 Astrophysique, Parc Valrose, 06108 Nice Cedex 2, France
3
Observatoire de la Côte d'Azur, Département CERGA, Avenue Copernic, 06130 Grasse, France
Corresponding author: J. Borgnino, borgnino@unice.fr
Received:
31
January
2000
Accepted:
3
May
2001
Solar diameter measurements performed with the Calern Observatory astrolabe (O.C.A - France) during more than two solar cycles show temporal variations. Due to the weather, seasonal effects and instrumental characteristics, recorded solar data are non uniformly sampled and present temporal gaps. Thus, to analyze these data, diameter measurements averaged over one or more months have generally been considered. This limits the accessible harmonic terms to a low frequency range. To determine short-term periodicities from the observed variations, all daily solar data need to be considered and also corrected from the zenithal distance. In the present work, we use two methods to analyze solar diameter measurements recorded at Calern Observatory astrolabe during the observation period 1975-1996. They are based on least square fits and deconvolution of the observation window function. Results deduced from the analysis confirm harmonic terms already found by other authors but also reveal new higher frequencies.
Key words: Sun: fundamental parameters / Sun: oscillations / methods: data analysis
© ESO, 2001
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.