Picard returns 1st image of Sun
28 July 2010
The CNES microsatellite has delivered a 1st image of the Sun. Teams on the ground will use this image to make final adjustments before the science mission begins.
6 receiving stations
The SODISM instrument is operating perfectly.
The French-developed 11-cm-diameter telescope, the nerve centre of the Picard observation system, has returned a 1st image of the Sun, dated 22 July, just 1 month after the satellite was placed in orbit.
“This allows us to check the instrument is working properly and make a few adjustments for data processing on the ground,” explains François Buisson, Picard project leader at CNES.
Images from the satellite do not arrive in a ready-to-use format.
“SODISM digital data are constructed from light captured by the telescope and sent via radio link to 1 of the 6 Picard receiving stations on the ground,” continues François Buisson. “They are then relayed to the CNES control centre in
The 11-year cycle
The wheels of this machine need to be well oiled, because SODISM will be acquiring 1 image of the Sun every minute for the next 2 years at least.
“Picard’s real strength is its ability to continuously observe the Sun for several years,” explains François Buisson. “It will obtain ultra-precise measurements of the Sun’s diameter as well as the radiant energy it emits to provide a better understanding of the relationships between these parameters over the course of the 11-year solar cycle.”
The Picard satellite was launched on 15 June 2010 from the Yasny base in Russia. Credits: CNES/D. Ducros.
The image of 22 July was acquired at a wavelength of 607 nm, but SODISM can also operate at 5 other wavelengths to observe such details as sunspots and faculae* as well as the Sun’s internal structure.
Besides SODISM, Picard also carries 2 radiometers to measure solar irradiance.
The mission scientists are thus hoping to unravel the mysteries of the “day star”.
*Small bright spots visible on the Sun’s surface.
