COSPAR ‘06, Beijing 19 July 2006

UV solar disc imagers of Kuafu-A

Pierre Rochus °Jean-François Hochedez *

Jean-Marc Defise °Pierre-Alexandre Blanche °

Udo Schuehle “

° Centre Spatial de Liège, CSL, Belgium

* SIDC- ROB, Royal Observatory of Belgium

“ MPS, Lindau, Germany

COSPAR ‘06, Beijing - 19 July 2006 J.-F. Hochedez, ROB-SIDC

International Telescope Suite for the Investigation of Solar Eruptive Events

ITSISEE (It’s easy! … SpW forecast…)

EDI (or ELATE?)

Euv + Lyman-Alpha Telescope

+ Guide Telescope

MOSESMulti Order Solar EUV Spectrograph

LyCo Lyman-alpha CoronagraphViCo Visible light Coronagraph

ITSISEE is an observatory for Solar Weather forecast and nowcast

COSPAR ‘06, Beijing - 19 July 2006 J.-F. Hochedez, ROB-SIDC

EDI = EUV + Lyman Alpha Telescopes

19.5 nm, Fe XII & Fe XXIV– Focal length 1200 mm – ~1 nm FWHM– Pupil = 33 mm diameter

121.6 nm, H Ly – Focal length 1200 mm – Purity: >70%, goal = 90%

– Pupil 50-60 mm TBC

2 filtergraph telescopes– FOV > 45 Arcmin– Pixel < 2.6 Arcsec, viz. 1k x 1k or more

– 1 minute non-stop cadence ! – More if possible, where/when useful

– 1 Gbit/day per telescope TBC

COSPAR ‘06, Beijing - 19 July 2006 J.-F. Hochedez, ROB-SIDC

The EUV Telescope (1/2)

SoHO-EIT (Jan. 1996) and Proba2-SWAP (Sep. 2007) heritage– CSL + ROB in Belgium

Off-axis Ritchey-Chretien

COSPAR ‘06, Beijing - 19 July 2006 J.-F. Hochedez, ROB-SIDC

The EUV Telescope (2/2)

Lighter mirrors Absence of external baffle

(There is room for internal baffling)

Mirrors– Multi-layer – super-polished

Smaller filters (at the entrance pupil)

COSPAR ‘06, Beijing - 19 July 2006 J.-F. Hochedez, ROB-SIDC

Proba2-SWAP (1/2)

A new EUV solar telescopefor the ESA PROBA2 mission

COSPAR ‘06, Beijing - 19 July 2006 J.-F. Hochedez, ROB-SIDC

New technologies:- APS CMOS detector- Off-axis optical design- Onboard image processing

Proba2-SWAP (2/2)

COSPAR ‘06, Beijing - 19 July 2006 J.-F. Hochedez, ROB-SIDC

The Lyman- Telescope

Quasi-identical optical design as the EUV one Heritage from TRC but off-axis

– Transition Region Camera, R. M. Bonnet, 1980

Multilayer coatings on the 2 mirrors– Al/MgF2/B4C or Al/MgF2 optimized for 1215 Å.

>70% purity (FWHM<7nm)

– ACTON RESEARCH filters (+ solarblind detector?)

COSPAR ‘06, Beijing - 19 July 2006 J.-F. Hochedez, ROB-SIDC

Solar science addressed by the EUV telescope

195 (1.6MK) is an established “General Purpose” coronal channel Observable in still images:

– Coronal Holes (CH are the source of the fast wind)– Active Regions & Filaments (AR are flare & CME sites)– Sigmoids, EUV flares, post-eruptive arcades…

Observable in image sequences:– Eruption/CME on-disc signatures

EIT waves & dimmings, CME mass estimates Filament instabilities leading to their eruption

Forecasting better– Progress about physics of event precursors– Inputs to SpW data assimilation codes

COSPAR ‘06, Beijing - 19 July 2006 J.-F. Hochedez, ROB-SIDC

Solar science addressed by the Ly telescope

Ly-a solar images have never been monitored– Not even by SDO-AIA (which has He II synergies), Preparation for S.O.– Brightest line allows fast cadence– Emission mechanisms (typ. 20 000K but actually 10-80 000 K)

Ly-a solar images will reveal (cf VAULT rocket experiment)– dense prominences in absorption and in emission (mass estimation)– … CH, jets, spicules (like in H )– Cool magnetic field lines over the photosphere at the limb (not seen in H )– Chromospheric response to Corona and flares, “moss”, Moreton waves…

EUV emission always associated with Ly-a emission– but not the reverse observe inside CH

Will improve solar irradiance models– Main energetic contribution to Earth lower ionosphere– Sources of Ly-a irradiance variability– Imaging give access to irradiance in the heliosphere

Planetary aeronomy

With ideas from Dr. A. Vourlidas (VAULT PI)

COSPAR ‘06, Beijing - 19 July 2006 J.-F. Hochedez, ROB-SIDC

Anticipated improvements of ELATE over SOHO-EIT

Use of CMOS imaging detector– 2k x 2k? Solarblind AlGaN CMOS detectors?– Smart camera schemes, optimal SNR

Improved calibrations– Optical element robustness improved– On-ground, in-flight (UV LEDs)

Polarimetry at Ly-alpha– Bommier, V.; Sahal-Brechot, S.; Leroy, J. L.

Optimised lossy image or movie compression schemes– 15x and up to 200x ! 1 min cadence or better– Moderate the concern of being at L1 (cf. telemetry)

Data filtering– Since SOHO, main progress is with CPU and algorithmic– Autonomous operations

e.g. triggering sub-field high cadence acquisition

COSPAR ‘06, Beijing - 19 July 2006 J.-F. Hochedez, ROB-SIDC

Mission complementarities (1/2)

Timeline & Missions complementarities

Soho C

IR

C

IR

C

IR

C

IR

Stereo CIS

CIS

CIS

CIS

CIS

Solar B I I I

SDO IR IR IR IR IR IR IR IR IR IR

PROBA2 IR IR IR

PROBA3 C C C

KUAFU CIS?

CIS?

CIS?

CIS?

CIS?

S.O. CI CI CI CI CI CI

06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

I : UV imagingC: CoronagraphR: UV Radiometer

S: stereo ability

S: stereo ability??

COSPAR ‘06, Beijing - 19 July 2006 J.-F. Hochedez, ROB-SIDC

2 ideas for Kuafu-A

ITSISEE well tailored for CME forecast but less so for flares’ (often CME-associated)

– Need for a full-sun wide range spectrograph or spectro-imager Array of 10 one-mirror low-resolution multilayer telescopes? Spectro-heliograph design (cf. Coronas-F mission)

– Interest for such an instrument exists in Europe (B, CH…)

Stereoscopy?– L1 brings constraints but could bring an extremely valuable

bonus: stereoscopy in coordination with the LWS mission SDO (AIA).

Parallax of possible L1 orbits to be assessed

COSPAR ‘06, Beijing - 19 July 2006 J.-F. Hochedez, ROB-SIDC

Conclusions

UV solar disc imagers of Kuafu-A (ELATE) Rest of the RS suite (ITSISEE) Whole scientific payload of the Kuafu mission

Inescapable for solar physics Solar Weather monitoring

in 2012-2017 and beyond