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Result on 2011/12/20
Gopal, Hong, Cho, Pertti, Seiji, and Akiyama discussed this solar source. We decided to select new filament eruption (S28W35) on 1998/06/22 05:56 as a main solar source of 1998/06/21 07:20 CME associated with IP-ejecta. Determining factors are location of X-ray arcade and consistency of the helicity sign between photosphere and MC. Therefore #6.2 changed to #6. #6.1 event remained at memo as a reference database.
Conclusively, this event was rejected from the list, because solar source located in over W15.
******Previous Memo*********************************
There are two solar source candidates. At the first time, we selected #6.2 event (1998/06/22 07:34 CME) as a 1st priority candidate. But from Nitta's suggestion, Gopalswamy, Yashiro, Xie, Makela, and Akiyama discussed and decided that #6.1 event (1998/06/21 07:20 CME) is better. Anyway #6.1 event was listed as "1998/06/21 05:35 CME" in the LASCO CME catalog. We found that there were two CMEs. So #6.1 changed to "1998/06/21 07:20 CME" on 2011/10/11.
Akiyama's opinion
I carefully checked the solar source of #6.2 and found the possibility of two EPs (1st:S50W15 and 2nd:S28W35) from NoRH movie. To compare between MLSO (1998/06/21 21:10) and MUDON (1998/06/22 07:38) Ha images, the shape of filament at S28W35 changed. In case of only 2nd possible EP, the helicity sign between photosphere and MC is the same. The MC axis both cylinder/torus fitting and the magnetic configulation of a eruptied neutral line are also matched. If 2nd EP is real, solar souce may be not too far from the disk center.
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From Nitta's E-mail (2011/09/25 3:30 PM)
# 6
I feel the selected eruption is too south, although I somehow agreed with the identification when we participated in Jie Zhang's paper. But if you look at the SXT movie (16 images between 4 UT and 9 UT on 21 June 1998), you may see trans-equatorial loops disappeared between 5 and 6 UT, probably in association with the flare/CME. The LASCO C2 CME encompasses the equator and the ICME may have reached L1. I would like to know how you preclude this event (in Jie Zhang's case it was listed as an alternative choice.)
From Yashiro's E-mail (2011/10/11 01:05 PM)
Event #6
I split the CME at 05:35UT on 1998/06/21 into two.
| Date | Time | CPA | WD | SPD | |
|---|---|---|---|---|---|
| OLD | 1998/06/21 | 05:35:10 | 256 | 163 | 192 |
| NEW1 | 1998/06/21 | 05:35:10 | 289 | 78 | 148 |
| VEW2 | 1998/06/21 | 07:20:26 | 257 | 158 | 222 |
The CME at 07:20 UT on 1998/06/21 associated with the disappearance of the trans-equatorial loop could be a primary candidate of the solar source of the event #6.
#Current Solar Source Candidate:
1998/06/22 07:34:39 191 119 278
http://cdaw.gsfc.nasa.gov/CME_list/UNIVERSAL/1998_06/jsmovies/1998_06/19980622.073439.p199g/c2_rdif.html
#New candidate:
1998/06/21 07:20:26 257 158 222
http://cdaw.gsfc.nasa.gov/CME_list/UNIVERSAL/1998_06/jsmovies/1998_06/19980621.072026.p254s/c2_rdif.html
LASCO+SXT:
http://cdaw.gsfc.nasa.gov/movie/make_javamovie.php?date=19980621&img1=lasc2rdf&img2=yohkoh_sxt
Gopal wants to look at the CME speed of the new candidate to make a decision.
[Additional Information]
Zhang et al. 2007 selected #6.2 CME.
In lower right pannel we can see a dimming of trans-equatorial loops between AR 8243 and AR 8252.
Yellow contour is a eruptive filament observed by NoRH. A filament of green contour may be also erupted at ~06:16. SXT observed most bright arcade loops at the green contour area. Yellow and green filament are located in different neutral lines.
