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

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

Solar and Heliospheric Observatory (SoHO) 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 an ESA/NASA Observatory launch on December Still working very well after 12 years of mission

SoHO 12 InstrumentsAcronym Coronal Diagnostics Spectrometer CDS Charge, Element, and Isotope Analysis System CELIAS Comprehensive Suprathermal and Energetic Particle Analyzer COSTEP Extreme ultraviolet Imaging Telescope EIT Energetic and Relativistic Nuclei and Electron experiment ERNE Global Oscillations at Low Frequencies GOLF Large Angle and Spectrometric Coronagraph LASCO Michelson Doppler Imager/Solar Oscillations Investigation MDI/SOI Solar Ultraviolet Measurements of Emitted Radiation SUMER Solar Wind Anisotropies SWAN Ultraviolet Coronagraph Spectrometer UVCS Variability of Solar Irradiance and Gravity Oscillations VIRGO

CDS monochromatic images Chromosphere and Corona

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

SUMER Observation of a coronal hole K C I nm K S II 125 nm K N V nm K O V 62.9 nm K Mg X 62.4nm K Fe XII 124nm

VIRGO complements 3 solar cycles of solar irradiance measurements

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

Wave propagating in the 1.4 MK low corona observed in Fe XII

Post flare waves propagating in the photosphere (MDI observation)

The magnetic carpet driven by near solar surface dynamos Thousands of magnetic field loops over the photosphere, enough energy to heat the corona

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).

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

SoHO/LASCO C2 Active corona and CMEs

SoHO/LASCO C3 CMEs and protons shower

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

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.

MDI determination of the solar interior rotation rate

Subsurface structure above a sunspot as derived from MDI measurements

Upper convection zone mapped from MDI observations

HINODE Solar Observatory Launch 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 arcsecsolar optical telescope (SOT) resolution for the observation of solar magnetic fields. The X-ray telescope (XRT) image the corona with a resolutionX-ray telescope (XRT) of three times as high as Yohkoh (Solar-A). The EUV imaging spectrometer (EIS) has very high sensitivityEUV imaging spectrometer (EIS)

SOT G-Band (420 nm) movie

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.

Hinode X-Ray telescope observation of soft X-ray corona for one solar rotation

X-ray corona and G band photosphere

STEREO MISSION Launch 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.

Sun Earth Connection Coronal and Heliospheric Investigation(SECCHI) four instruments mounted 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.

The Heliospheric imager The HI-1 and HI-2 telescopes are set to and 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.

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

COR2 A and B 2 to 15 solar raduis field

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

Solar Dynamics Observatory To be launched in August 2008 NASA 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.SOHO/MDI 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.

THE PICARD satellite A CNES (French space agency) mission with Belgium and Swiss participation To 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.

1999 Début Doraysol 30 years of ground based solar diameter measurements

AuthorsLocationCycle Amplitude (mas) durationMeth./Inst. Ulrich, 1995Mt WilsonIn phase Scanning Penna et al, 2002Rio Astrolabe Noel, 2003SantiagoIn Phase Astrolabe Sveshnikov, 2004In Phase Transit de Mercure Delmas, 2002CalernOpposition Astrolabe Sofia et al., 1985Opposition /1979Eclipses Brown, 1998HAO Méridien Wittmann, 2003Tenerife-< Méridien G. Thuillier Ground based solar radius measurements situation

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

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.

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

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 ( ) measured the solar diameter. It was 1 arc sec larger than its present value.

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,...)

SMESE Instrumentation -LYOT: LYman imaging Orbiting Telescope A Ly  coronagraph & disk imager with high cadence (~10 s), high sensitivity and polarimetric capability -DESIR: Detection of Eruptive Solar InfraRed emission A 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

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.

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

A very active Sun

CMEs impact the magnetosphere (CLUSTER)

SOT observation of a prominence

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 km/s.

Soft X-Ray active region followed 12 days

Hinode Soft X-Rays telescope

Mercury as seen by the two COR1 telescopes The planet Mercury as seen by the two COR1 telescopes on May 3, 2007.Also shown is the calculated position and size of the solar disk.

Heliospheric imager (HI) Optical flow observation