Solar Rotation Nos: 2256 to 2257
There were no spotless days in May with multiple sunspots being visible on every day. Sunspot activity is currently at a similar level last seen in 2015. The southern hemisphere was more active than the north.
Here are the solar highlights for May 2022 with a selection of images.
Sunspots
AR2999 appeared on the last day of April at latitude -20° on the southern hemisphere and was still visible on the May 1st. It was seen nearing the SW limb of the Sun on the 3rd and had gone over the limb by the 7th.
AR3001 also appeared on April 30th at the slightly higher southern latitude of -32° and was visible in early May nearing the west limb of the Sun. There was not much change seen thereafter and it was not seen after the 11th.
AR3004 came into view on the SE of the solar disc near the Central Meridian (CM) at -16° on the 3rd. It developed sunspots rapidly on the 4th and 5th becoming minor solar flare active and visible to the protected naked eye. The group didn’t seem to change much after that, and it went over the SW limb around the 11th.
At this point the SW quadrant of the Sun was active with sunspots as AR2999, AR3001 and AR3004 were seen clustered near the SW limb.
AR3006 came over the east limb on the 5th at -29°. It crossed the CM on the 10th and was complex magnetically enough to give rise to a strong X-class solar flare on the 10th at 1355UT which was seen in hydrogen-alpha. It developed slightly more to type Eao on the 12th. It faded rapidly to a few pores nearing the SW limb.
AR3007 appeared over the east limb at -23° on the 8th and rapidly developed more sunspots the following day becoming type Cao. It developed further and was type Ehc on the 12th. By the time it reached the CM on the 14th it had grown slightly more to type Ekc. It remained active as it headed westwards until it was seen nearing the west limb on the 18th by which time it was slightly decayed. It went over the limb around the 20th.
AR3011 appeared over the E limb on the 14th at latitude +16°.I seemed to decay as it neared the CM and was not seen after the 18th.
AR3014 appeared on the 16th at +21° developing more sunspots overnight going from type Cao into slightly larger type Dac the following day. By the 20th and 21st it was near the CM and by then developed to type Ekc and large enough to be seen with the protected naked eye. It was also solar flare active. By the 23rd AR3014 could be seen on the NW quadrant of the solar disc. It seemed to decay slightly thereafter and went over the limb around the 29th.
AR3015 appeared near AR3007 and AR3014, not far from the E limb, on the 16th at +14°. It developed then faded away by the 21st.
AR3017 came over the E limb on the 17th. By the 23rd it had developed more sunspots becoming type Cro that day. It developed into type Dai by the 24th and grew to type Eso on the 25th as it was seen nearing the W limb. It was not seen after the 29th having gone over the W limb.
AR3024 came over the E limb on the 26th noticeable for being at the high southern latitude of -33°. It did not show much change as it neared the CM on the last day of May.
SPA Sunspot Mean Daily Frequency: 3.97 (was 3.87)
Relative Sunspot Number: 52.74 (was 55.74)
Solar Prominences, Plage, Filaments and Flares
An arch-type prominence was seen on the E limb on the 11th. A large hedgerow prominence appeared on the SW limb on the 12th. Tall prominences were seen on the 14th on the E, S and W limbs and on the N, E and S limbs on the 18th.
A tall arch-type prominence was seen on the NW limb on the 19th.
An arch-type prominence was seen on the W limb on the 29th.
Numerous solar filaments (some quite small and fragmented in nature) were seen on the 5th, 8th, 11th, 14th, 18th. A very broad filament appeared between AR3006 and the W limb on the 12th.
Numerous bright plage were seen with the sunspots as they crossed the solar disc throughout May.
Solar flare was seen on the 19th within AR3014.
SPA Prominence Mean Daily Frequency: 4.64 (was 7.68)
Congratulations to Jonathan Shanklin who observed 29 days in May and to Alan Heath (27 days) and Simon Brown (26 days).
Detailed count records of Active Regions and Relative Sunspot Numbers came from: Simon Brown, John Chapman-Smith, Michael Fullerton, Alan Heath, Ian Lee and Jonathan Shanklin.
Images and drawings were supplied by: Carl Bowron, Paul Brierley, John Chapman-Smith, Alan Clitherow, Mick Jenkins, Ian Lee, Cliff Meredith and Larry Todd.
Geoff Elston