Solar radius variations using LOI-T guiding pixels

Barrena, R.; Roca-Cortés, T.; Jiménez, A.
Bibliographical reference

In: Proceedings of the SOHO 10/GONG 2000 Workshop: Helio- and asteroseismology at the dawn of the millennium, 2-6 October 2000, Santa Cruz de Tenerife, Tenerife, Spain. Edited by A. Wilson, Scientific coordination by P. L. Pallé. ESA SP-464, Noordwijk: ESA Publications Division, ISBN 92-9092-697-X, 2001, p. 75 - 78

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2001
Number of authors
3
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0
Citations
0
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0
Description
The LOI (Luminosity Oscillations Imager) is a low resolution solar photometer built at the SSD of ESA. It is one of the instruments in the VIRGO experiment on board the SOHO satellite. In May 1994, the Qualification Model of the LOI was installed at the Observatorio del Teide (Tenerife) and since then it has been working continuously (LOI-T). The intrument has 4 guiding pixels in a ring shape around 12 central pixels. This ring has an internal radius of 15.12 arcmin and it is 1.68 arcmin width. Each guiding pixel is a quadrant of an annulus and it is oriented on one of the geographic directions: North, South, East and West. With these pixels, several signals can be derived that might be used as a measure of the solar shape: radius, oblateness, etc. Results of more than five years observations are presented.