Abstract
In this work we describe solar radius measurements made from 1972 with the Sao Paulo astrolabe. We find values of 959.52 ± 0.03 arcsec for the visual data and 959.61 ± 0.05 arcsec for the CCD data using a modified data acquisition system. We compare our results with other astrolabe measurements and with SOHO-MDI. Observations of the solar radius show contradictory results when we try to correlate changes in the diameter with the solar cycle. Our series is not correlated with the solar cycle but it shows a period of 13.4 ± 2.2 yr. We have also compared our time series with other long-term measurements of solar radius along solar cycle 21 and analysed our measurements as a function of heliographic latitude. We do not find a significant solar oblateness.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.