LASCO Activity Report for
April 21, 2004 SOHO Science Daily Meeting

Event times are first frame seen in C2 camera unless otherwise noted.
These are preliminary observations for the daily SOHO science discussions.
Final analysis is reported on the Lasco CME list.
An archive of these reports is available.

Points Of Interest

Comet C/2004 F4 (Bradfield) is not longer in the C3 field of view. 
'Nominal' synoptic observations reestablished on 2004/04/20 at ~15:00 UT.

SOHO Telemetry Submode changed to Submode 5 on 2004/04/13 at 16:00 UT 
(SUMER began observing on 2004/04/14). SUMER campaign runs until 2004/06/17.
In other words, LASCO synoptic observation plan cadence remains the same
but the EIT CME watch images will be reduced to half-resolution (512x512).

2004/04/20

	04:54 UT		Last C3 frame where Comet Bradfield is visible
				(upper right). Tail still visible. 

05:08 UT  S West	Ragged loop front and trailing material. Faint extension
			over the S Pole just at the beginning in the form of a 
			diffuse front that quickly fades. EIT Fe XII running
			difference images show signatures of the event over
			the SW limb, coming from behind the disk.

09:42 UT  N West	Ragged loop front with twisted inner structure.

10:08 UT  E Limb	Elongated ragged front. At 09:42 UT a diffuse front 
			precedes it, fading pretty quickly. Apparently twisted
			trailing material. It fades in C3. Tops of post-CME
			arcade visible over the ESE limb by 09:00 UT in EIT 
			Fe XII running difference images. Barely backsided.

14:42 UT  W Limb	A ragged front is guessed to appear developing toward 
			NW and somehow seems to push the two structures already
			under development on NW and SW. It is difficult to
			discern whether is an independent event or if it is just
			part of the event reported to start at 09:42 UT. The
			whole resulting complex event (as seen in C2 FOV) spans
			almost 180 deg, from NW to SE.

2004/04/21

00:06 UT  S Pole	Couple of wide front loops.