Dear Collaborators,
Solar activity remains at a very low level. The target region NOAA 12821
and nearby slightly larger region NOAA 12820 have both decayed somewhat
since the last message. 12820 produced a few low-B-class flares, and no
change in flare activity is expected in the following 24 hours. At this
point the Max Millennium target changes to support the coordination of
observations for the 8th perihelion passage of Parker Solar Probe (PSP
encounter 8). The target is the expected magnetic-footpoint location of
PSP that is currently estimated as being the edge of the Southern polar
coronal hole close to the South East limb.
The approximate position of this region on 28-Apr-2021 at 21:00 UT is:
S55E85 , ( -543", -774" )
See http://www.SolarMonitor.org for images and
http://solar.physics.montana.edu/max_millennium/ops/observing.shtml
for a description of the current Max Millennium Observing Plan.
Regards,
Shaun Bloomfield (Northumbria University)
Dear Collaborators,
The level of solar activity is very low. Target region NOAA 12821 has
grown marginally in extent, number of spots and spot area and is now
classified as a beta/D-type sunspot group, while close-by NOAA 12820
has grown in extent to be classified as a beta/E-type sunspot group.
Both of these regions have produced several B-class flares since the
last message, with NOAA 12821 producing the largest of the period (a
B3.3 flare on 27-Apr-2021 at 16:04 UT). NOAA 12821 becomes the target
region for the next 24 hours, but observers are encouraged to include
the leading portion of NOAA 12820 in their field-of-view if possible.
Further B-class activity is expected in the next 24-hour period, with
a good chance for a C-class flare.
The position of NOAA 12821 on 27-Apr-2021 at 20:00 UT is:
S21W39 , ( 561", -287" )
See http://www.SolarMonitor.org for images and
http://solar.physics.montana.edu/max_millennium/ops/observing.shtml
for a description of the current Max Millennium Observing Plan.
Regards,
Shaun Bloomfield (Northumbria University)
Dear Collaborators,
Solar activity is at a low level. The target region NOAA 12820 has generally
maintained spot area since the last message while developing small spots in
its interior. This region continues to be classified as a beta/D-type sunspot
group. The bipolar flux region located slightly to the West of 12820 has now
been designated as NOAA 12821 (a beta/C-type sunspot group). NOAA 12820 has
continued to produce multiple B-class events since the last message, but the
largest flare in the period was a C2.6 event on 26-Apr-2021 at 01:17 UT from
decaying NOAA 12816. The target remains as NOAA 12820 for the next 24 hours,
but observers are encouraged to include the trailing portion of 12821 in the
field-of-view if at all possible (because the trailing spot of NOAA 12821 is
moving towards the opposite polarity leading spot of NOAA 12820). Continued
B-class activity is expected in the following 24 hours, with a good chance
for a C-class flare.
The position of NOAA 12820 on 26-Apr-2021 at 22:00 UT is:
S22W18 , ( -274", -290" )
See http://www.SolarMonitor.org for images and
http://solar.physics.montana.edu/max_millennium/ops/observing.shtml
for a description of the current Max Millennium Observing Plan.
Regards,
Shaun Bloomfield (Northumbria University)
Dear Collaborators,
The newly emerged region near NOAA 12818 has been designated as
NOAA 12820 with a beta/D-type configuration. 12820 has produced 10
B-class flares since the last message, the largest one being a B6.9 at
04/24/16:45 UT. If possible, please include both regions in your field of
view. Note that the largest X-ray event of the period was a C2.6 at 04/25/
01:17 UT, produced by NOAA 12816 (S24W53) that has entered its decay
phase. Further C-class activities are expected with a slight chance of an
isolated M-class event in the next few days.
The position of NOAA 12820 on April 25 at 15:30 UT is:
S22W01 (15", -284")
See http://www.SolarMonitor.org for images and
http://solar.physics.montana.edu/max_millennium/ops/observing.shtml
for a description of the current Max Millennium Observing Plan.
Regards,
Ying Li (Purple Mountain Observatory)
Dear Collaborators,
Yesterday's target region NOAA 12817 has rotated over the west limb.
Today the target will switch to NOAA 12818. 12818 produced a C2.5
flare at 04/23/23:08 UT and also a B3.2 flare. Please note that there n
ewly emerged some sunspots in its leading portion (or at the west of its
old leading polarity). Additional C-class activities are expected in the
next 24 hours.
The position of NOAA 12817 on April 24 at 07:30 UT is:
S17E21 (-328", -207")
See http://www.SolarMonitor.org for images and
http://solar.physics.montana.edu/max_millennium/ops/observing.shtml
for a description of the current Max Millennium Observing Plan.
Regards,
Ying Li (Purple Mountain Observatory)
Dear Collaborators,
The target region NOAA 12817 produced more than 10 C-class
flares in the past 24 hours, the largest one being a C8.5 flare at
04/22/20:02 UT. 12817 was designated as a beta/C-type configuration.
We will keep watching this region until it rotates beyond the west limb.
Another sunspot region NOAA 12816 (S24W20, beta/C-type) also
produced one C1.0 flare during the period. Further B-class activities
are expected with C-class events probable in the next 24 hours.
The position of NOAA 12817 on April 23 at 03:30 UT is:
N18W91 (906", 292")
See http://www.SolarMonitor.org for images and
http://solar.physics.montana.edu/max_millennium/ops/observing.shtml
for a description of the current Max Millennium Observing Plan.
Regards,
Ying Li (Purple Mountain Observatory)
Dear Collaborators,
The target region NOAA 12817 produced numerous B-class activities
as well as two C-class flares (C2.7 and C1.7 in the past two hours,
maybe the former one is from NOAA 12816, to be confirmed). 12817
remains its beta/D-type configuration but increases its sunspot area
and current helicity. Please also note that NOAA 12816 (beta/C-type)
shows some opposite flux emergence in its leading portion though it
is in the decay phase. Further B-class activities are expected and
additional C-class activities are probable, with a very slight chance
of an isolated low M-class flare in the next few days.
The position of NOAA 12817 on April 22 at 03:30 UT is:
N18W81 (896", 306")
See http://www.SolarMonitor.org for images and
http://solar.physics.montana.edu/max_millennium/ops/observing.shtml
for a description of the current Max Millennium Observing Plan.
Regards,
Ying Li (Purple Mountain Observatory)
Dear Collaborators,
NOAA 12817 was the source of numerous B-class flares as well as
two C-class flares (C1.9 and C1.5) in the past 24 hours. 12817 has
been designated as a beta/D-type region, with increasing its sunspot
area and number of spots. Today the target will switch to this region
that continues to show flux emergence. Further B-class activities are
expected and additional low C-class events are very likely when 12817
rotates to the west limb.
The position of NOAA 12817 on April 21 at 03:30 UT is:
N18W64 (817", 329")
See http://www.SolarMonitor.org for images and
http://solar.physics.montana.edu/max_millennium/ops/observing.shtml
for a description of the current Max Millennium Observing Plan.
Regards,
Ying Li (Purple Mountain Observatory)
Dear Collaborators,
The target region NOAA 12816 produced an M1.1 flare at 04/19/23:19 UT
and also a B8.0 flare, which were the largest two X-ray events of the period.
12816 has been classified as a beta/D-type region, increasing in the sunspot
area and number of spots. It continues to show flux emergencies and also
cancellations. The newly emerged region mentioned in the last message
was designated as NOAA 12817 (N18W50) with a beta/B-type region. This
region has produced numerous B-class flares. Further B-class activities are
expected and some C-class activities are probable in the following 24 hours.
The position of NOAA 12816 on April 20 at 15:30 UT is:
S24E17 (-256", -312")
See http://www.SolarMonitor.org for images and
http://solar.physics.montana.edu/max_millennium/ops/observing.shtml
for a description of the current Max Millennium Observing Plan.
Regards,
Ying Li (Purple Mountain Observatory)
Dear Collaborators,
The largest X-ray event since the last message was a B6.9 flare
at 04/19/07:44 UT produced by the south-east limb region (S18E88)
mentioned in the last message. This region is too close to the limb
to obtain its magnetic configuration. Today the target region remains
to be NOAA 12816 that has a beta/C-type sunspot group with increasing
in the sunspot area and number of spots. 12816 was the source of six
low B-class flares (the largest one being a B3.8) during the period. It
continues to emerge opposite fluxes in its leading portion. There also
emerged a new region with some sunspots in the northwest quadrant
(N16W41, unnumbered yet) that has produced two ~B3 flares. More
B-class flares are expected with a chance of some C-class activities
in the next 24 hours.
The position of NOAA 12816 on April 19 at 15:30 UT is:
S25E25 (-367", -331")
See http://www.SolarMonitor.org for images and
http://solar.physics.montana.edu/max_millennium/ops/observing.shtml
for a description of the current Max Millennium Observing Plan.
Regards,
Ying Li (Purple Mountain Observatory)