European and French solar physics from space

1. European and French solar physics from space Jean ARNAUD Laboratoire FIZEAU Observatoire de la côte d’Azur Université de Nice Sophia Antipolis

2. Introduction Space Solar Physics is a very active field of research in many countries including the US, Europe and Japan. A strong tradition of international cooperation exist here. Observing programs can be proposed by scientists world while on almost all solar physics missions and data generally become public domain very soon. I will present major missions the European community is largely involved in, like SoHO, STEREO, HINODE and SDO and two smaller missons: PICARD and SMESE

3. Solar and Heliospheric Observatory (SoHO) an ESA/NASA Observatory launch on December 2 1995 Still working very well after 12 years of mission • Main goals of the SOHO mission: study the internal structure and outer atmosphere of the Sun, as well as the origin of the solar wind. • 12 Instruments for the study of: • Corona and solar wind • Helioseismology • Solar constant • In situ particules measurements

5. CDS monochromatic imagesChromosphere and Corona

6. Loops at different temperatures in the same solar atmosphere region observed by CDS

7. SUMER Observation of a coronal hole 10 000 K C I 124.9 nm 30 000 K S II 125 nm 190 000 K N V 123.8 nm 250 000 K O V 62.9 nm 1 100 000 K Mg X 62.4nm 1 400 000 K Fe XII 124nm

8. VIRGO complements 3 solar cycles of solar irradiance measurements

9. Tornado in the Fe XI corona (about 1 million K), EIT Observation

10. Wave propagating in the 1.4 MKlow coronaobserved in Fe XII

11. Post flare waves propagating in the photosphere (MDI observation)

12. The magnetic carpetdriven by near solar surface dynamosThousands of magnetic field loops over the photosphere, enough energy to heat the corona

13. Coronal Masses Ejections (CMEs) • CMEs are linked to flares (energetic particules events) and eruptives prominences for at least 75% of them. • CMEs are triggered by magnetic field instabilites. • Waves in the low corona can be associated to CMEs (EIT) • Most CMEs originate from the chromosphere (EIT and LASCO) • SoHO (UVCS) demonstrated that the CME is colder than the corona (prominence material).

14. Flux cancellation creates twisted flux ropes (Amari et al., 2007) .

15. SoHO/LASCO C2 Active corona and CMEs

16. SoHO/LASCO C3 CMEs and protons shower

17. Open questions concerning CMEs • CMEs result from magnetic field instabilities but we do not know the precise mechanisms which trigger and accelerate CMEs. • We do not know why and how CMEs are linked to flares and prominences. • We do not know the actual 3D geometry of CMEs

18. MDI deep interior of the Sun speed of sound determination In red sound travels faster than theoretical prediction, implying higher temperatures than expected; in blue lower than expeted temperatures. The shear layer between the radiative and the convection zones, where most of the solar magnetic field is generated, is hotter than expected. The solar core is 0.1% cooler than the standard model Sun.

19. MDI determination of the solar interior rotation rate

20. Subsurface structure above a sunspot as derived from MDI measurements

21. Upper convectionzone mapped from MDI observations

22. HINODE Solar ObservatoryLaunch in September 2006 • Hinode is a japanese mission with important US and UK participation. Hinode (Solar-B) is equipped with three advanced solar telescopes. Its solar optical telescope (SOT) has an unprecedented 0.2 arcsec resolution for the observation of solar magnetic fields. The X-ray telescope (XRT) image the corona with a resolution of three times as high as Yohkoh (Solar-A). The EUV imaging spectrometer (EIS) has very high sensitivity

23. SOT G-Band (420 nm) movie

24. Movie made from SOT images showing prominences above an active region at the limb. Detailed analysis of those high-resolution (0.25 arcsec) images in the visible attributes the waving motion of a prominence to Alfvén waves in the corona.

25. Hinode X-Ray telescope observation ofsoftX-ray corona for one solar rotation

26. X-ray corona and G band photosphere

27. STEREO MISSIONLaunch in October 2006 • This two-year mission employs two nearly identical space-based observatories - one ahead of Earth in its orbit, the other trailing behind - to provide the first-ever stereoscopic measurements to study the Sun and the nature of its coronal mass ejections, or CMEs. • STEREO's scientific objectives are to: • Understand the causes and mechanisms of coronal mass ejection (CME) initiation. • Characterize the propagation of CMEs through the heliosphere. • Discover the mechanisms and sites of energetic particle acceleration in the low corona and the interplanetary medium. • Improve the determination of the structure of the ambient solar wind.

28. Sun Earth Connection Coronal and Heliospheric Investigation(SECCHI) four instrumentsmounted on each of the two STEREO spacecraft - an extreme ultraviolet imager (EUVI) - two white-light coronagraphs COR1: Inner Coronagraph and COR2: Outer Coronagraph - a heliospheric imager (HI) These instruments will study the 3-D evolution of CME's from birth at the Sun's surface through the corona and interplanetary medium to its eventual impact at Earth.

29. The Heliospheric imager • The HI-1 and HI-2 telescopes are set to 13.98 and 53.68 degrees from the Sun, along the ecliptic line, with fields of view of 20 and 70 degrees, respectively. This provides on overlap of about 5 degrees.

30. Stereo COR2 vision of a CME a CME early phase seen both edge & face-on A. Vourlidas

31. COR2 A and B 2 to 15 solar raduis field

32. CMEs and waves in the fields of vue of COR2, HI-1 and HI-2

33. Solar Dynamics ObservatoryTo be launched in August 2008NASA Mission with international participation • HMI (Helioseismic and Magnetic Imager) • The Helioseismic and Magnetic Imager will extend the capabilities of the SOHO/MDI instrument with continuous full-disk coverage at higher spatial resolution. • AIA (Atmospheric Imaging Assembly) • The Atmospheric Imaging Assembly will image the solar atmosphere in multiple wavelengths to link changes in the surface to interior changes. Data will include images of the Sun in 10 wavelengths every 10 seconds. Will extend the capabilities of TRACE: same spatial resolution,larger field. • EVE (Extreme Ultraviolet Variablity Experiment) • The Extreme Ultraviolet Variablity Experiment will measure the solar extreme-ultraviolet (EUV) irradiance with unprecedented spectral resolution, temporal cadence, and precision. Measures the solar extreme ultraviolet (EUV) spectral irradiance to understand variations on the timescales which influence Earth's climate and near-Earth space.

34. THE PICARD satelliteA CNES (French space agency) missionwith Belgium and Swiss participationTo be launched in June 2009   Three instruments SODISM measures the solar shape and diameter. SOVAP measures the total solar irradiance.PREMOS measures irradiance in four spectral domains and the total solar l'irradiance.   

35. 1999 Début Doraysol 30 years of ground based solar diameter measurements

36. Ground based solar radius measurements situation G. Thuillier

37. Lack of constitency between results due to: • Diameter definition • Quality of measurements - Spectral domains (Fraunhofer lines) - Data processing - Atmospheric (seeing) effects

38. SODISM (SOlar Diameter Imager and Surface Mapper) is a telescope, inside a temperature stabilized carbone-carbone structure, 11 cm in diameter, a filter system and a 2048 x 2048 CCD.SODISM will measure the solar diameter in three spectral regions at 535, 607 and 782 nm free of Fraunhofer lines.

39. SODISM Optical design 4 prisms in a ring at the telescope entrance give 4 auxiliary solar images used for guiding and for calibration of the telescope focal length. The aim of SODISM is to get a precision of about 1 milliarcsec on the diameter measurement. This mean that the focal length has to be know with a relative precision of 10-6.

40. PICARD scientific objectives - Precise measurement of the solar diameter and of its variations (if any) with the solar cycle phase and determine if solar diameter variations are linked to the solar activity. - Determine with the help of PicardSol (a SODISM copy + a atmospheric monitor on ground) if the solar diameter can be monitor using groung based instruments. - Help to understand the effect of solar activity on climate. The Maunder minimum (1645–1715) of solar activity did correspond to a ‘little ice age” in Europe and America. Jean Picard (1620-1682) measured the solar diameter. It was 1 arc sec larger than its present value.

41. The Small Explorer for Solar Eruptions (SMESE) A French-Chinese cooperation in solar Physics To be launched in 2013 China: PMO : Purple Mountain Observatory, CAS NJU : Nanjing University CSSAR : Center for Space Science and Applied Research (Beijing) NAOC : National Astronomical Observatory, CAS(Beijing) CNSA : Chinese National Space Agency France : LESIA/OP : Laboratoire d’Etudes Spatiales et d’Instrumentation en Astrophysique (Paris Observatory) IAS : Institut d‘Astrophysique Spatiale (Orsay) CNES : Centre National d‘Etudes Spatiales Collaborations with other Institutes (LAM, LPCE, MPS, Torino/Firenze, CSL, Brazil, ...)

42. SMESE Instrumentation • LYOT: LYman a imaging Orbiting Telescope ALy  coronagraph & disk imager with high cadence (~10 s), high sensitivity and polarimetric capability • DESIR: Detection of Eruptive Solar InfraRed emissionA Far IR telescope performing photometry and source localisation to catch synchrotron (particles) and thermal (chromosphere) radiations : a first • HEBS: High Energy Burst Spectrometer A HXR & gamma-ray spectrograph over an unprecedented energy range, going well above the RHESSI limit (10 MeV) : 10 keV – 600 MeV

43. Conclusion • Solar Physics from Space is a very active area of research • SoHO and succeeding missions are giving a new vision of the Sun, demonstrating how active is its atmosphere and how its influences the earth environment. They are giving new insights on the solar interior and its rotation, on the solar wind acceleration, on flares and CMEs, on the origins of the magnetic field among many other things. • Those missions also emphasized the importance of the magnetic field for heating the solar corona, accelerating the solar wind, triggering flares and CMEs ejections. Even if we still miss the detailed mechanisms at the origin of a large part of those phenomenon, progress in solar physics are very important. • Improving spatial resolution and determining the magnetic field in the full solar atmosphere are keys for further improvements in understanding the physics of our star.

44. The Milky Way in the HI 1 A field Field of 14 degres centered 20 degres from the Sun

45. A very active Sun

46. CMEs impact the magnetosphere(CLUSTER)

47. SOT observation of a prominence

48. A movie of a coronal active region above the Sun « surface », close to an equatorial coronal hole. Looking to the left of center in the sequence of images, an outflow of material (plasma) was measured to be movinng at 10 km/s. Material outflow in regions like this one, is thought to be a source of the low-speed solar wind. High-speed solar wind has speeds of 600-800 km/s.

49. Soft X-Ray active region followed 12 days

50. Hinode Soft X-Rays telescope