1. Study of a coronal mass ejection using STEREO/SECCHI and SOHO/LASCO observations
Alisson Dal Lago1, Bernd Inhester2, Luis Eduardo Antunes Vieira2
1National Institute for Space Research, Sao Jose dos Campos - SP, Brazil
2 Max-Planck-Institute for Solar System Research, Katlenburg-Lindau, Germany

2. Outline
CME on Jan 8-9, 2007.
SOHO: LASCO C2 (Jan 8, 2007, at 14:54UT, PA 65); LASCO C3 (Jan 8-9, 2007) ;
STEREO: SECCHI COR1 A&B; SECCHI COR 2 A&B; SECCHI HI-1 A.
Solwind – Helios observations
Estimate of CME travel time to Venus x observations
Summary
2007/01/08
2007/01/09
Dal Lago et al., ILWS

3. Motivation
2007/01/08
2007/01/09
Schwenn, Dal Lago, Huttunen (Kilpua) and Gonzalez, Ann. Geophys., 2005
Dal Lago et al., ILWS

4. The CME on Jan 8-9 2007 Set of observations
SOHO: LASCO C2 (Jan 8, 2007, at 14:54UT, PA 65); LASCO C3 (Jan 8-9, 2007) ; EIT (did not detect any activity – CME behind the East limb).
STEREO: SECCHI COR1 A&B; SECCHI COR 2 A&B; SECCHI HI-1 A.
2007/01/08
2007/01/09
SECCHI/COR1 B 14:41 UT
LASCO/C3 01:42 UT
Dal Lago et al., ILWS

5. The CME on Jan
STEREO/SECCHI COR 1 B (1.4-4 solar radii) 2007/01/08 14:41 UT 5º
H (solar radii)
SOHO LASCO C3 (4-32 solar radii) /01/09 02:42 UT
STEREO/SECCHI COR 1 B PA65 5º
Time (h)
SOHO LASCO C3 PA 65
H (solar radii)
Time (h)
Dal Lago et al., ILWS 5

6. The CME on Jan
STEREO/SECCHI COR 1 B (1.4-4 solar radii) 2007/01/08 14:41 UT 5º
H (solar radii)
STEREO/SECCHI COR 1 B PA65
Time (h)
Dal Lago et al., ILWS 6

7. Coronagraph (2 – 18 solar radii)
STEREO/SECCHI COR 1 B (1.4-4 solar radii) 2007/01/08 14:41 UT
SOHO LASCO C3 (4-32 solar radii) /01/09 02:42 UT
SOHO LASCO C3 PA 65
H (solar radii)
STEREO/SECCHI COR 1 B PA 65
Time (h)
Dal Lago et al., ILWS

8. Coronagraph (2 – 40 solar radii)
STEREO/SECCHI COR 1 B (1.4-4 solar radii) 2007/01/08 14:41 UT
STEREO/SECCHI HI-1 A /01/09
H (solar radii)
STEREO/SECCHI COR 1 B PA155
Time (h)
Dal Lago et al., ILWS

9. The CME on Jan 8-9 2007 Sun Venus Coronal Mass Ejection
Dal Lago et al., ILWS

10. The CME on Jan 8-9 2007 Sun Venus Jan 8, 2007
Dal Lago et al., ILWS

11. The CME on Jan 8-9 2007 Sun Venus
t1AU = 203 – 20.77*ln(Vexp); (Schwenn et al., 2005) (1)
t1AU (Vexp=260km/s) = 87 hours (2)
T0.72AU = 0.72* t1AU (3)
hence,
T0.72AU = 63 hours (4)
Vexp
1 AU
Venus
Vrad
Dal Lago et al., ILWS

12. Solwind - Helios Sun Venus
Quadrature observation of CMEs and corresponding ICMEs using SOLWIND coronagraph and Helios 1 plasma analyzer
at heliocentric distance of AU, from 1979 to 1982 (adapted from Sheeley et al., 1985).
Dal Lago et al., ILWS

13. Solwind - Helios *
Dal Lago et al., ILWS

14. The CME on Jan
Dal Lago et al., ILWS

15. The CME on Jan
Dal Lago et al., ILWS

16. The CME on Jan
Dal Lago et al., ILWS

17. The CME on Jan
Dal Lago et al., ILWS

18. The CME on Jan 8-9 2007 Sun Venus Vexp 1 AU Venus Vrad
Dal Lago et al., ILWS

19. The CME on Jan
Summary
Observed by SOHO’s LASCO C2/C3 and STEREO SECCHI COR1A&B/2A&B and HI1A
Detailed information was extracted using image processing techniques;
CME released in the direction of Venus;
Solwind – Helios comparison
Various methods to predict travel time to Venus: not successful.
Dal Lago et al., ILWS

20. The CME on Jan 8-9 2007 Acknowledgements
The authors would like to acknowledge SOHO LASCO and EIT work team and STEREO SECCHI work team for providing the data used in this work.
SOHO is a project of international cooperation between ESA and NASA.
STEREO SECCHI data are produced by an international consortium of the Naval Research Lab. (US), Lockheed Martin Solar Astrophysics Lab (US), NASA Goddard Space Flight Center (US), Rutherford Appleton Lab (UK), Univ. of Birmingham (UK), Max-Planck-Institut für Sonnensystemforshung (Germany), Centre Spatiale de Liege (Belgium), Institut d’Optique Théorique et Appliqueé (France), and the Institut d’Astrophysique Spatiale (France).
A. Dal Lago would like to acknowledge “Conselho Nacional de Desenvolvimento Científico e Tecnologico – CNPq”, of Brazil, for financial support.
Dal Lago et al., ILWS