PICARD scientific workshop at CNES Headquarters

The workshop will gather the Principal Investigators, the Co-Investigators, as well as the PICARD Guest Investigators. Its objective will be to present the latest scientific results, to tackle some important technical problems for the scientific exploitation of the data, to identify some possible cooperations between laboratories, etc.

PICARD/SODISM and SDO/HMI agreement

Philip H. Scherrer (Stanford University) PI of HMI mission on board SDO and Alain Hauchecorne (LATMOS) PI of PICARD mission, signed a Letter of Intent for scientific and technical cooperation between these two space missions.

Technological experimentations with PICARD satellite

PICARD International Steering Committee ratified the recommendation of the REDEM Steering Committee not to extend PICARD mission in. Following the PICARD Exploitation Review of November 27 and 28, 2012, CNES proposed to realize in flight experimentations with the PICARD satellite during the phase F. In order to prepare these experimentations, a call for ideas has been issued at the beginning of 2013 to the CNES technical services, as well as ASTRIUM and THALES ALENIA SPACE. 16 propositions have been received and 9 have been selected. 7 propositions are underway until the end of October 2013; they concern:

the study of the SODISM instrument CCD detector performances,
the validation of the CORTEX Quantum equipment performances and the functionalities of the S Band interface,
the analysis of PICARD star tracker performances, as well as the validation of its performances improvement due to the modifications in its software,
the inspection of PICARD by Mango/PRISMA satellite: a rendez-vous demonstration with a non-cooperative satellite (PICARD) will be performed then the inspection of this satellite by the Swedish satellite Mango/PRISMA.

Other propositions should take place at the beginning of 2014, and should enable to:

validate the autonomous guiding defined by ISIS for the future missions,
enable to validate a new command law for the wheels for the future missions.

In addition, CNES endorsed the laboratories demand to acquire, when possible, payload data during these technological operations.

The solar oblateness measurement: history of the measurements, objectives and scientific results

(MP4 format 108 Mb)

The millionth image of SODISM instrument

Since the launch of PICARD mission (June 15, 2010), SODISM instrument acquired its millionth image in January 2013. This observation has been done at a particular wavelength: the calcium line (Ca II K) in the night-blue part of the solar spectrum. The interest in this observation at such a wavelength (393.37 nm) is that it reveals the regions of the chromosphere and detects the active regions of the Sun (facules and spots). These images are mainly dedicated to the study of the solar activity and enable to measure the differential rotation. The instruments of the space mission PICARD are pursuing their acquisitions. The data exploitation and the scientific activities are continuing...

Image acquired by SODISM instrument on January 12, 2013

Solar eclipse on November 13, seen by PICARD

Animation of SODISM images acquired during the solar eclipse by the moon at 535 nm wavelength on November 13, 2012.

Movies of the Presentations of the scientific PICARD workshop held on April 10th, 2012 at CNES Paris are now available in the Media Gallery!

The history of Venus transits

Video presenting the history of Venus transits observed by men from Galileo to PICARD

© CNRS - CNES
QuickTime format low or medium resolution
~ 133 or 191 Mb

Presentations of the scientific PICARD workshop held on April 10th, 2012 at CNES Paris

The workshop presentations are available through its agenda.

The Picard satellite observed the Venus Transit

Here are the first images of SODISM telescope (at 607 nm) on board PICARD satellite of the Venus Transit (credits CNES/CNRS-LATMOS)

Venus transit in front of the Sun

Animation of the Venus transit in front of the Sun
(avi format ~80 Mb)

The satellite is rotating around the Earth while keeping focus on the Sun. This would cause a sine wave like pattern to be observed for the path of the object between the satellite and the Sun (Venus of course in this case).

The Picard satellite will observe the Venus Transit on June 5-6

With the data obtained during the Venus Transit on June 5-6, the Picard satellite will improve our knowledge of the shape of the sun, and provide an accurate measure of the Sun diameter.

Location and time of the Venus transit in front of the Sun

Another interest is to test current methods to search the exoplanets by the transit method (variation the light intensity received at the detectors level). Other scientific objectives are targeted as the study of the Venus atmosphere.

From a technical standpoint, the VENUS Transit will help the PSF determination of the SODISM instrument.

Eclipse flower seen by PICARD

On this image taken by the SODISM instrument on board Cnes' satellite Picard on May 20th, a strange "Moon flower" seems, like the Little Prince's rose, to have grown on our natural satellite limb.

Of course, without atmosphere and liquid water, no flower can grow on the Moon. This beautiful plant was just a group of sun spots that the perspective placed at the limb of the Moon during the partial solar eclipse by the Moon.

Group of sun spots looking like a flower growing on the Moon's limb
Credits: CNES/CNRS-LATMOS

Continuously ausculting our star since June 2010, Picard satellite was ideally placed to photograph this partial eclipse.

Note that Picard will also be well placed to observe Venus transit in front of our star on June 6th, the last transit before 2117!

PICARD Scientific Workshop at CNES headquarters in Paris

This workshop objective is to present the first results of the mission, as well as the instruments in-flight performances. Another objective will be to prepare a Call for "Guest Investigators" and PICARD data use.

The workshop will be held at:

Centre national d'études spatiales
2 place Maurice Quentin
75039 PARIS Cedex 01
FRANCE

For more information and inscription to the workshop, contact Michel Rouzé

The enormous Sun spot that produces eruptions

The origin of the solar eruption on the March 7, 2012 is a big sun spot that appeared on March 2 on the border of the Sun. This spot is named AR 1429 by astronomers.

The SODISM telescope of the PICARD satellite captured a set of images at 393 nm wavelength, more particularly between March 6 and 9. Theses images show the evolution of AR 1429 position, which extends on a length equivalent to 8 times the Earth diameter!!!

 
Images taken between March 6 and 9 by Sodism telescope at 393 nm wavelength © CNES/CNRS-LATMOS

The different and powerful solar eruptions that took place during this period could have provoked magnetic disturbances in the Earth's environment (especially for satellites). They also are at the origin of magnificent polar aurora, which result from the entry of solar particles in the atmosphere.

PICARD observes a new partial Sun eclipse

     
Partial Sun eclipse on 01/08/2011 at 21h59, 22h02, 22h05, 22h07, 22h10 and 22h14 at 535 nm

The six images above have been taken on June 1st, 21h59, 22h02, 22h05, 22h07, 22h10 and 22h14 (Universal Time UTC) at the wavelength of 535 nm.
They enable to observe the transition of the Moon between the Earth and the Sun.

Otherwise, scientists pursue their analysis and interpretation work of the enormous volume of data collected.

PICARD observes the partial Sun eclipse

   
Partial Sun eclipse on 04/01/2011 at 8h25, 8h26, 8h27 and 8h28 at 782 nm

The four images above have been taken on January 4th, 2011 at 8h25-8h26-8h27 and 8h28 (Universal Time UTC) at the wavelength of 782 nm while the satellite flew over Greenland.
They enable to observe the transition of the Moon between the Earth and the Sun.
The Sun image is gradually shifted from the center of the image, due to the satellite driving principle which points towards the gravity center of the lighted part of the Sun.
From a scientific point of view, the interest of this observation is limited because the eclipse is partial. Nonetheless, by using SOVAP and PREMOS instruments measurements, the consequences of the darkening of the center-border of the Sun on the total and spetral radiation can be studied.

Otherwise, scientists pursue their analysis and interpretation work of the enormous volume of data collected.

Scientific Mission Center delivery to its operator

The delivery key point (hand over) of PICARD CMS took place on November 23 and 24, 2010, in Brussels with representatives from CNES, which was the prime contractor for this development, from B-USOC which is its operator, from Belpso, which funds the development and the operations and from IASB which hosts it.
The CMS-P was developed by the Belgian company Spacebel.
After the key point, the CMS-P was accepted without reservation by its operator. The operations responsibility, conducted in coordination with the Mission Operations Preparation Group (scientific group) and its maintenance switches from CNES to B-USOC.
These last delivery and responsibility change conclude the passage of PICARD system to routine operation mode.

CNES and B-USOC responsibles working

Bruno Millet PICARD system responsible with Dominique Fonteyn, Belspo Director

Definitive opening of SOVAP right shutter

SOVAP instrument was victim, since July 26, of a dysfunction of the entry shutter of the right cavity. Faced with this issue, the instrument responsibles decided to let this shutter permanently open; however the different commands sent to this objective failed until November 18 when the opening manoeuvre succeeded. The shutter will now stay open until the end of the mission, enabling the instrument to ensure its scientific mission.

Entry in eclipses period

The 6h00-18h00 orbit choice is dedicated to minimize the eclipses periods during the year, interrupting the continuous observation of the Sun. This period is thus limited to a few weeks around the winter solstice.
It begun on November 12 and the eclipses duration will gradually increase to reach the value of 20 mn on December 20.
The eclipse entry and exit go with a period during which the Sun is seen through the atmosphere, which refracts its rays: the Sun image is thus distorted and seen in a different direction than the real one.
During this absorption period, the satellite stay guided as long as possible by its solar ecartometry sensor, in the Sun direction. The scientific instruments continue the acquisition of measurements in order for SODISM, to study the distortion of the limb through the atmosphere, and for the radiometers, to analyse the impact of the atmosphere on the spectral repartition of the solar radiation.
At the beginning of the eclipse, the pointing is realised by star sensors.
At the end of the eclipse, the satellite stay pointed in the theoretical direction of the Sun until the solar ecartometry sensor receives enough solar flux to enable a correct pointing. This period is used by SODISM to try to evaluate the impact of the temperature variation of its front part (it was notably cooled during the eclipse) on the instrument metrology.

The graphic above represents the variation (expressed in arc second) between the direction aimed by the satellite and the direction of the Sun. Two eclipses periods can be observed with an important variation during the beginning and the end of the eclipse (effect of the switch between the star sensor and the solar ecartometry sensor) and a decreased pointing performance when the satellite is driven by the star sensors instead of the solar ecartometry sensor.

PICARD declared ready for duty

The in-flight commissioning operations successfully ended on October 8.
The system was declared ready to begin the exploitation phase after the in-flight commissioning review.
The Calibration Validation phase, dedicated to the last tuning to reach the system ultimate performances thus begins.

New images of the Sun taken by SODISM instrument

SODISM instrument continu its regular acquisition of images of the Sun (one each minute). The 5 images below have been taken at 5 wavelength of SODISM instrument SODISM. They have been obtained after application of a processing to correct the main optical and radiometric defaults of the raw images.

Image at 535 nm taken on 04/09/2010 at 13h31	Image at 607 nm taken on 02/09/2010 at 04h04
Image at 782 nm taken on 03/09/2010 at 09h04
Image at 215 nm taken on 22/09/2010 at 03h53	Image at 393 nm taken on 22/09/2010 at 04h23

The images at 535 nm, 607 nm and 782 nm are mainly used to measure the Sun's diameter and the study of its shape.
The images at 215 nm and 393 nm are mainly used to study the solar activity.

All these images enable to visualise several sun spots. These images confirm the increase of the solar activity.

High resolution AVI format ~26,5 Mb High resolution MOV format ~23 Mb Low resolution AVI format ~2,4 Mb Low resolution MOV format ~2,7 Mb

This video is a series of images taken at the wavelength of 393 nm between August 5 and 31, 2010. It shows a nearly complete rotation of the Sun.
These images have been obtained after processing to correct the main defaults of the instrument.

First stellar pointing

During the in-flight commissioning operations, PICARD successfully realised its first stellar pointing sequence.
During this particular operation, the satellite doesn't point towards the Sun, but towards a couple of stars which angular distance is near the value of the solar diameter, located in the opposit direction from the Sun. The image taken by SODISM serves to compare the distance between the stars as measured by the instrument to the distance foretold by Hipparcos catalogue, to calibrate, in the absolute, the measurement function of SODISM.

First image of the Sun taken by SODISM instrument on July 22, 2010 at 16h12. It is a raw image, level L0, thus obtained before processing, at 607 nm wavelength in a very narrow band of 0.5 nm width.

Several solar spots can be seen in the lower left part. These spots appear at high solar lattitude then move slowly towards the solar equator, their number increasing with the solar activity.

First image of the Sun taken by SODISM instrument on July 22, 2010 - Wavelenth 607 nm

The 607 nm wavelength enables to measure the shape (diameter, flatening) of the solar disk at the photosphere level.
SODISM also has filters at 215, 393, 535 and 782 nm, enabling to study the active regions (sun spots, facula) as well as the Sun internal structure interne (heliosismology).
The CCD has 4 Millions pixels.

PICARD payload is also composed of 2 radiometers measuring the total and spectral solar irradiance. PICARD is a solar metrology mission, not an imaging mission. The wealth of the mission is in the continuous observation of the Sun during several years to get very precise measurements of characteristics such as the diameter and the emitted power, their variations (with a precision of about 10^-6) and their relations during all the increasing phase of the 11 years solar cycle.

End of the first operations to bring the payload to operational configuration: the 3 instruments are now functioning, all their parameters are nominals.
SODISM is in decontamination mode, at the mean temperature of 25°C; dark current images are regularly acquired.
All the system componants (satellite and payload, control center, network, mission center) are fonctioning nominally.

Evolution of SODISM temperatures during its passage in decontamination.

Successful launch of PICARD satellite together with the Swedish satellites PRISMA, in a DNEPR launcher.

(MP4 format ~6.5 Mb)