Study of a coronal mass ejection using
STEREO/SECCHI and SOHO/LASCO
observations
Alisson Dal Lago1, Bernd Inhester2, Luis Eduardo Antunes Vieira2
1National
2
Institute for Space Research, Sao Jose dos Campos - SP, Brazil
Max-Planck-Institute for Solar System Research, Katlenburg-Lindau, Germany
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 - 2009
Motivation
140
LASCO-ACE
Solwind-Helios
120
travel time (h)
100
80
60
40
20
0
0
500
1000
1500
2000
2500
3000
3500
halo expansion speed (km/s)
2007/01/08
2007/01/09
Schwenn, Dal Lago, Huttunen (Kilpua) and Gonzalez, Ann. Geophys., 2005
Dal Lago et al., ILWS - 2009
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
SECCHI/COR1 B 14:41 UT
2007/01/09
LASCO/C3 01:42 UT
Dal Lago et al., ILWS - 2009
The CME on Jan 8-9 2007
STEREO/SECCHI COR 1 B (1.4-4 solar radii) 2007/01/08 14:41 UT
SOHO LASCO C3 (4-32 solar radii)
2007/01/09 02:42 UT
H (solar radii)
5º
STEREO/SECCHI COR 1 B PA65
5º
Time (h)
H (solar radii)
SOHO LASCO C3 PA 65
Time (h)
Dal Lago et al., ILWS - 2009
The CME on Jan 8-9 2007
STEREO/SECCHI COR 1 B (1.4-4 solar radii) 2007/01/08 14:41 UT
H (solar radii)
5º
STEREO/SECCHI COR 1 B PA65
Time (h)
Dal Lago et al., ILWS - 2009
Coronagraph (2 – 18 solar radii)
SECCHI COR1B
SECCHI COR2B
LASCO C3
LASCO C2
SECCHI COR2A
SECCHI COR1A
LinFit COR1B
Vcor1B = 70.97 km/s
Est. onset date/time:
2007/01/08 07:42 UT
LinFit LASCO C3
Vc3 = 283.77 km/s
PA 155 deg.
18
16
14
12
10
8
SOHO LASCO C3 (4-32 solar radii)
UT
2007/01/09 02:42
6
4
2
14
16
18
20
22
24
26
28
30
32
time (h)
Jan. 8th-9th, 2007
SOHO LASCO C3 PA 65
H (solar radii)
H
(solar radii)
STEREO/SECCHI COR 1 B (1.4-4 solar radii) 2007/01/08 14:41 UT
STEREO/SECCHI COR 1 B PA 65
Time (h)
Dal Lago et al., ILWS - 2009
Coronagraph (2 – 40 solar radii)
Leading edge of the CME at PA 65 derived from visual detection of the radial intensity profile.
SECCHI COR1B
SECCHI COR2B
LASCO C3
LASCO C2
SECCHI COR2A
SECCHI COR1A
SECCHI HI1A
40
35
30
SECCHI COR1B
Vcor1B = 70.97 km/s
Est. onset date/time:
2007/01/08 07:42 UT
LASCO C3
Vc3ps = 283.77 km/s
SECCHI HI1A
Vhi_1a = 345.59 km/s
PA 65 deg.
25
20
15
10
5
STEREO/SECCHI HI-1 A
2007/01/09
0
12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42
time (h)
Jan. 8th-9th, 2007
H (solar radii)
H
(solar radii)
STEREO/SECCHI COR 1 B (1.4-4 solar radii) 2007/01/08 14:41 UT
STEREO/SECCHI COR 1 B PA155
Time (h)
Dal Lago et al., ILWS - 2009
The CME on Jan 8-9 2007
Sun
►
Venus
Coronal Mass Ejection
Dal Lago et al., ILWS - 2009
The CME on Jan 8-9 2007
Sun
Venus
Jan 8, 2007
Dal Lago et al., ILWS - 2009
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 - 2009
Solwind - Helios
Sun
Venus
Quadrature observation of CMEs and corresponding ICMEs using SOLWIND coronagraph and Helios 1 plasma analyzer
at heliocentric distance of 0.72+ 0.05 AU, from 1979 to 1982 (adapted from Sheeley et al., 1985).
Year
CME date
CME time
1979
1981
1981
1981
1982
Oct. 10
May 8
Jul. 22
Nov. 15
Nov. 22
07:13
23:35
20:49
00:15
20:30
CME
speed
(km/s)
170
1000
800
550
620
ICME date
ICME time
Oct. 13
May 10
Jul. 24
Nov. 16
Nov. 24
02:00
03:20
15:28
15:19
00:01
Helios 1
helioc.
Dist. (AU)
0.72
0.67
0.74
0.67
0.74
Travel
time from
the Sun (h)
67
27
43
39
27.5
Dal Lago et al., ILWS - 2009
Solwind - Helios
*
Dal Lago et al., ILWS - 2009
The CME on Jan 8-9 2007
Dal Lago et al., ILWS - 2009
The CME on Jan 8-9 2007
SECCHI COR1B
SECCHI COR2B
LASCO C3
LASCO C2
SECCHI COR2A
SECCHI COR1A
LinFit COR1B
Vcor1B = 70.97 km/s
Est. onset date/time:
2007/01/08 07:42 UT
LinFit LASCO C3
Vc3 = 283.77 km/s
PA 155 deg.
16
H
(solar radii)
14
12
10
8
10
8
H
(solar radii)
18
 SECCHI COR2B
 SECCHI COR2A
 LASCO C2
PA 65 deg.
V = 120 km/s
6
6
4
4
2
2
14
14
16
18
20
22
24
26
time (h)
Jan. 8th-9th, 2007
28
30
32
15
16
17
18
19
20
21
22
23
24
25
time (h)
Jan. 8th-9th, 2007
Dal Lago et al., ILWS - 2009
The CME on Jan 8-9 2007
Dal Lago et al., ILWS - 2009
The CME on Jan 8-9 2007
Dal Lago et al., ILWS - 2009
The CME on Jan 8-9 2007
Sun
Venus
Assumption
Travel time to 0.72 AU (hours)
comparison with similar past 67
events (Sheeley et al., 1985)
CME
travel
time
model 63
(Schwenn et al., 2005) adapted
to 0.72AU
constant final LASCO C3 velocity 105
Estimated arrival date/time in
Venus
Jan. 11th (2007), 09:54 UT
Jan. 11th (2007), 05:54 UT
Jan. 12th (2007), 23:54 UT
Vexp
1 AU
Venus
Vrad
Dal Lago et al., ILWS - 2009
The CME on Jan 8-9 2007
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 - 2009
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 - 2009