SOLAR REPORT FOR APRIL 2023
Carrington Rotation Numbers: 2269-2270
Again, many thanks to all members who sent in observations. The rate of observing was quite high, and the section has managed, so far, to monitor solar activity on a near continuous basis since October 22.
I did a talk at the SPA meeting on the 29th of April, which I attempted to showcase the members work, and give the results of the Section in the form of the MDF graph, which shows activity since 1978.
Most of the images are shown on the News part of the Solar Section Website and can be referenced by the dates shown.
Activity overall was low, but some large groups were seen. Despite the low MDF activity may well increase as we approach the Solar Maximum.
Detailed report as follows:
2 April 23. The solar disc showed little in the way of active regions. The ones showing were small individual spots or pores. Hydrogen alpha view showed ‘tree’ prominences and a couple of smaller ‘hedgerow’ type prominences, with large filaments across the disc.
3 April 23. This showed the emergence of small group AR3270. AR3262 and AR3262 had reached the west limb. In hydrogen alpha, with the exception of a few small prominences and small filaments, activity was low.
4 April 23. AR3270 had developed into a bipolar group with a large spot leader and follower. Activity was still low. Hydrogen alpha images show detached and large prominences around the edge of the disc, and some fairly long filaments.
6 April 23. AR3270 appeared to be decaying, especially in the follower spot, and slightly smaller leader.
7 April 23. Activity was still low as the main group reaches the southwest limb. AR3272 came around the limb and seemed to be surrounded by faculae. Hydrogen alpha views showed some filaments to the south and north, and some small prominences, including detached ‘cloud’ prominences, around the disc.
8 April 23. AR3272 continued to transit and appeared to be developing. AR3270 had reached the southwest limb. Activity was still low. Hydrogen alpha view showed some prominences around the disc and some small filaments across the face.
9 April 23. The only main group was AR3272, but there were signs that other active regions were beginning to emerge.
10 April 23. AR3272 had now become a wide small, spot/pore group, but AR3272 was developing with some pore followers. Another spot had come over the east limb.
11 April 23. AR3272 and AR3273 still transiting, now joined with two new areas, one in the north and one in the south in the east. Activity was still low.
12 April 23. AR3272 and AR3272 still apparent and showing little change to their configuration. AR3276, in the south, appeared to be active with masses of faculae surrounding it.
13 April 23. AR3272 appeared to a fairly wide, more dispersed, group. Noticeable was the small active region developing above to the front of this group. AR3279 is showing as a small line of spots leading to the limb with surrounding faculae.
15 April 23. New groups, AR3282 and AR3281 appear to be active in the east, and AR3280 had developed into a group proper, with a spot leader and spot/pore followers. AR3272 had appeared to be decaying and appeared faint, showing only a few pores. Hydrogen Alpha showed a large, complex prominence, to the west.
16 April 23. AR3282 had developed slightly and the groups AR3276, AR3279, and AR3281 appears as a ‘chain’ of groups in the south.
17 April 23. AR3282 had decayed slightly but is now a bipolar group. Otherwise not much change from the previous day.
18 April 23. AR3282 had developed slightly but the follower spot showed decay, and the leader getting larger. All other groups remained stable. Hydrogen alpha showed a large hedgerow prominence to the north and a few filaments across the disc.
19 April 23. AR3282 still changing in the leader now increasing in size and the follower now decreasing in size. Other groups now decaying and getting more faint. Hydrogen alpha shows a ‘spire’ prominence in the north and a small ‘hedgerow’ nearby.
20 April 23. This day was noticeable for the total eclipse of the Sun to the west of Australia. The activity on the Sun showed AR3282 had the leader spot again increase slightly and the follower beginning to disperse. The four groups in the south are still faint, consisting of small spot/pores. Hydrogen alpha shows a large ‘spur’ prominence to the north, (and was observed when the eclipse occurred), along with the ‘hedgerow’ prominence and a smaller ‘spray’ prominence.
21 April 23. AR3282 continues to transit and the follower spot had almost decayed completely, but new umbral activity was occurring in the penumbra of the leader spot. The other regions were apparent but had decayed and very faint. A new spot had come over the southeast limb.
22 April 23. AR3282 continues to head towards the west limb showing only a remnant of the follower spot. AR3285 is a small bipolar group transiting the disc.
23 April 23. AR3285 is a small, stable bipolar group. AR3282 has reached the west limb, showing only a small follower spot.
24 April 23. As AR3282 goes over the west limb, AR3285 is the largest group. Activity is low.
25 April 23. Activity still low with only one main active region, AR3285, transiting the disc. Hydrogen alpha shows some activity with four main prominences and distinct filaments across the face.
27 April 23. Slight increase in activity. AR3285 had been joined with AR3288 to its south and two other regions in the centre of the disc. AR3289 had come over the northeast limb.
28 April 23. AR3289 had developed slightly, and AR3285 and AR3288 almost appear as one group. AR3291 had also developed.
30 April 23. AR3289 had developed into a small, close group. AR3285 and AR3288 still appear as one (The difference in numbers is due to the groups being on different latitudes).
I would like to ask if there is any member or person wishing to take on the Directorship of the Section prior to me leaving on the 31 August. If you are interested please do get in touch with me using the email address on the SPA Solar Section website.
Images and data were sent in by Mark Beverage, Ian Lee, Michael Fullerton, Roger Heard, Carl Bowron, Lee MacDonald, Jonathan Shanklin, Cliff Meredith, Larry Todd and the Director.
Results will be updated as and when observations arrive.
MDF = 3.97 (amended 3 June 23)
R = 50.97 (amended 3 June 23)
Prom R = 9.02
John Chapman-Smith
Acting Solar Section Director