Skip to Main content Skip to Navigation
Journal articles

New space value of the solar oblateness obtained with PICARD

Abstract : The PICARD spacecraft was launched on June 15, 2010 with one of its sci- entific objectives the study of the geometry of the Sun. The measure of the solar oblateness remains difficult because images are affected by optical distortions. Rolling the satellite as performed in previous space missions, allows determi- nation of the telescope contribution by assuming the geometry of the Sun is constant during the observations. This supposes that the telescope optical re- sponse is time-invariant during the roll operations. It is not the case for PICARD since an orbital signature is clearly observed in the solar radius computed from its images. We take into account this effect and provide the new space value of the solar oblateness obtained from PICARD images recorded in the solar continuum at 535.7 nm in July 4-5, 2011. We obtain 8.4 ± 0.5 mas for the equator- pole radius difference, which corresponds to an absolute radius difference of 6.1 kilometers. It is in good agreement with the mean value of all solar oblate- ness measurements obtained during the two last decades from ground, balloons and space. It is also consistent with values determined from models using helioseismology data.
Complete list of metadata

Cited literature [12 references]  Display  Hide  Download

https://hal.archives-ouvertes.fr/hal-00952233
Contributor : Catherine Cardon <>
Submitted on : Wednesday, February 26, 2014 - 1:47:51 PM
Last modification on : Saturday, December 12, 2020 - 12:10:03 PM
Long-term archiving on: : Monday, May 26, 2014 - 12:00:35 PM

File

irbah0218.pdf
Files produced by the author(s)

Identifiers

Citation

Abdanour Irbah, Mustapha Meftah, Alain Hauchecorne, Djelloul Djafer, Thierry Corbard, et al.. New space value of the solar oblateness obtained with PICARD. The Astrophysical Journal, American Astronomical Society, 2014, 785 (2), pp.89. ⟨10.1088/0004-637X/785/2/89⟩. ⟨hal-00952233⟩

Share

Metrics

Record views

1080

Files downloads

486