Each
month a summary of sunspot activity is written and forms part of a
report sent to the Solar Section of the British Astronomical
Association (BAA)
and to The
Astronomer. Follow
the links below to read a
page summary of
sunspot activity. The McIntosh Sunspot Group Classification is used for
sunspot group descriptions.
January
2016
Another
particularly cloudy month
restricted observing to 8 days. The
largest of the six groups seen on the 8th was AR 2480 of type Eac near
the
eastern limb at 3°N/123° and area 180 millionths. The
largest
sunspot within
the group was the leader. By
the 10th a
few additional pores were seen within the group. When next seen on the
15th and
16th AR 2480 had become type Hsx with an area of 100 millionths and now
approaching the western limb. To
the
north of AR 2480 was AR 2483 initially seen as an Axx sunspot at
17°N/126° on
the 8th before developing into a small Dso group on the 10th with an
area of 60
millionths. Like AR 2480, AR 2483 was seen as an Hsx sunspot on the
15th and
16th.
On
the 23rd a small Dai group, AR
2488, was seen approaching the central meridian at
4°N/320° and
area 90
millionths. Although the number of follower sunspots had reduced by the
following day, the leader had enlarged and contained several umbrae
– the total
area of this now Cai group had increased to 190 millionths. AR 2488 was
of a
similar type and size on the 28th but of type Hsx close to the limb on
the
30th. An Eac group was also seen on the 28th – this being AR
2489
at 10N/252
and area 210 millionths. The main sunspot was the leader. By the 30th
most of
the followers had disappeared to leave a Cai group where the leader had
an area
of 230 millionths. AR 2488 and 2489 were the only groups seen on the
30th.
Hydrogen
Alpha:
Based on four Hα observations, the
most notable prominences were on the 10th which combined with a
filament on the
NE limb and on the 30th when an ejected prominence was seen above the
SE limb.
It stretched for some 15° along the limb with a maximum height
of
about 90,000
km. It
comprised of several distinct
regions of hydrogen. Many filaments were seen on each of the four days
–
particularly long filaments were seen on the 16th in the north and on
the 23rd
in the centre of the disk. The
length of
these on the disk was about 40° and 35° respectively.
Plage was
seen around AR
2485 on the 16th and AR2488 on the 30th and close to the limb.
February
2016
None
of the
groups seen during
the month were particularly large.
Of
particular note were AR 2494, 2497 and 2506.
AR
2494 was initially seen on the 7th as a Dac group at
11°S/163° with
an area of 180 millionths – the follower was the largest
sunspot.
By the 9th,
with the group approaching the western limb, AR 2494 the follower had
split but
the group was of the same type and similar size. A small Hsx sunspot
was all
that remained by the 11th when it was close to the limb.
One
of the other groups seen on
the 7th was AR 2497 at 13°N/84° of type Dsc and close
to the
eastern limb – it
comprised several small penumbral sunspots and several pores. When seen
on the
9th it now resembled a normal bipolar group of type Dsi with an area of
70
millionths. The longitudinal extent of AR 2497 had increased by the
11th to
make the group type Eac and it was also near the central meridian. None
of the
several penumbral sunspots were particularly large as the total area
was just
180 millionths. By the 14th it has reverted back to a Dsc group and it
appeared
as a collection of small penumbral and other sunspots. It was also the
only
group seen on this date. AR 2497 was last seen close to the limb on the
17th a
three small penumbral sunspots.
One
of the three groups seen on
the 23rd was an Axx group, AR 2506, close to the eastern limb at
8°S/222°. It
was still of type Axx on the following day before developing into a
small Cso
group on the 25th and 26th. On the 28th with the group near the central
meridian it became type Dsc with an area 110 millionths. On the 29th
most of
the pores between leader and follower had disappeared to leave a Dso
group with
a total of area 80 millionths.
Hydrogen
Alpha:
The Hα observation on the 7th
showed a few small prominences but quite a few short filaments plus
plage
around AR 2497. The other observation on the 28th showed two taller
prominences
on almost opposite sides of the solar disk, both being variants of
arches, fewer
filaments and plague around AR 2506 near the centre of the disk.
March
2016
Activity
reduced slightly
compared to previous months and again none of the groups were
particularly
large. The northern
hemisphere
was still
dominant. The number of groups seen varied from seven on the 4th the
one on the
22nd & 23rd and between the 29th and 31st.
Groups
of particular note were AR 2513, AR 2519, AR 2524
and AR 2526.
The
largest group seen during the
start of the month was AR 2513 – it was initially seen on the
3rd
as a single
Hsx sunspot at 10°N/101° near the eastern limb. It
remained of the same form during its passage across the
solar disk
although it had a peak size of 120 millionths on the 5th and it was
last seen
nearing the western limb on the 13th. Another single Hsx sunspot
appeared close
to the eastern limb on the 11th – AR 2519. This sunspot, at
5°N/12°, had a
couple of attendant pores on the 16th when its area peaked at 120
millionths.
These pores had decayed by the 20th when AR 2519 was near the western
limb.
Yet
another Hsx sunspot was seen
close to the eastern limb on the 16th. However by the following day a
following
penumbral sunspot was also seen – AR 2524 at
14°N/277°
was of type Eso. By the
20th two pores were seen between the leader and follower and the group
has a
total area of 210 millionths. When
seen
on the 22nd and 23rd AR 2524 was just past the central meridian and the
only
group seen. As the group approached the limb it began the decay with
being type
Cso on the 25th and type Hsx on the 27th and 28th.
The
final group seen during the
month was AR 2526. It was initially seen as a moderately sized Hsx
sunspot at 4°S/176°
on the 25th. As it moved away from the eastern limb, a small number of
attendant sunspots appeared. AR 2526 was in the middle of the disk on
the 30th
of size 250 millionths. It appeared as a single Hsx sunspot on the 31st. AR
2526 was seen with the protected naked eye
on each day between the 27th to 31st inclusive (despite it being
smaller than
the nominal 500 millionths required for sunspot to be visible by the
protected
naked eye).
Hydrogen Alpha:
On the 6th double vertical jet
prominence was seen on the SW limb where the base both jets were above
the
limb. Small prominences were seen below the jets attached to the limb.
On the
13th a sticking prominence was seen on the SE limb which was in the
form of an
irregular arch. Two detached prominences were seen above the same part
of the SE
limb on the 25th and 28th – both appeared as horizontal slabs
of
hydrogen. Although
filaments were
seen on
each of the 7
observations, the longest ones were seen on the 25th.
Plage
was around AR 2506 and 2510 on the 4th,
AR 2512 on the 6th, AR 2521 on the 13th, AR 2524 on the 20th and AR
2526 on the
25th, 27th and 28th.
April
2016
Although
activity in terms of the
number of active areas and sunspot number was similar to previous
months, there
was particular interest because of the moderately sized group AR 2529
seen
between the 8th and 19th and an unusual bipolar group at the end of the
month. The number
of groups
seen during
the first
three weeks were either one or two but during the last week up to six
groups
were seen. As during recent months the northern hemisphere was
dominant.
Several groups were seen close to the solar equator, an indication of
activity
during the declining part of solar cycles.
The
largest group seen during the
first week was AR 2526 at 3°S/176° which on the 2nd was
of type
Hax and area
140 millionths. It was last seen very close to the western limb on the
5th.
The
observation on the 8th showed
that AR 2529 had rotated around the eastern limb at
9°N/340°
and of type
Dko. The dominant
sunspot
was the
leader. On the 10th the group was now of type Ekc with an estimated
area of 830
millionths. The
dominant leader was
asymmetric in shape while there were two much smaller followers. It was
also
the only group seen. On subsequent days the leader became more
symmetrical
while the followers reducing in size.
The
shape of the umbrae also changed from day to day. The
total area was
slightly reduced at 740 millionths on the 12th.
When
next observed on the 16th, with AR 2529 now past the
central
meridian, the size of the group had reduced the 600 millionths and the
followers were all small. As the group neared the western limb, its
reduced in
size such that on the 17th it was 490 millionths and no followers were
seen on
the 18th and 19th. AR 2529 has rotated around the limb on the 20th. AR
2529 was seen with the protected naked eye
on the 10th, 11th, 12th, 16th, 17th and 18th.
On
the 23rd AR 2533 was the only
group seen – it was of type Hsx, of size 100 millionths and
very
close to the
solar equator at 2°S/182°.
By
the
26th,
five groups were seen which increased to six on the 27th and 28th. These
additional groups were spread across
the solar disk. All
were small in size
but one was of particular interest.
This
was AR 2536, initially seen as a small single Hsx sunspot at
14°N/118° close to
the eastern limb. On the following day two small sunspots had developed
towards
the south of the penumbral sunspot.
One
of these southern sunspots developed further into small penumbral
sunspot of
similar size to the northern penumbral sunspot.
Thus
AR 2536 had the appearance of a bipolar Dsi group
which was highly
inclined to the solar equator – quite unusual given that most
bipolar groups
have the line between the leader and follower inclined by only a few
degrees. By
the 30th, the northern penumbral sunspot increased in size towards the
direction of the southern penumbral sunspot. The total area was 150
millionths
(SDO HMI Magnetogram images indicated that the northern and southern
ends of AR
2536 has different polarity thus indicating that this was indeed a
bipolar
group with a high inclination angle).
Hydrogen Alpha:
The most striking prominences
were seen in the 2nd when a cloud prominence was seen above the NE limb
and a
curved prominence above the SW limb – a filament was seen
near
the base of this
prominence. A small combined prominence/filament was seen on the E limb
on the
5th. An interesting filament structure was seen around AR 2529 on the
16th and
17th when several filaments appearing to emanate from the centre of the
group. Plage was
seen around
AR 2528 on
the 4th, AR
2529 on the 16th and 19th, AR 2532 on the 19th and 24th, AR 2536 on the
29th
and AR 2537 on the 29th.
Images:
The white light image below of AR
2529 from the 10th and 17th were taken with a 105mm ETX telescope,
Baader N3.8 Solar
Film and Imaging Source Camera. The Hα image from the 17th
was
taken with a PST
and Imaging Source Camera.
May
2016
One
of the five
groups seen on
the 1st was the unusual bipolar group AR 2536 at
14°N/118° now
just past the
central meridian. The northern penumbral sunspot has reduced in size to
be more
like the southern penumbral sunspot and several pores were seen within
the
group as shown in the image. By the following day the leading southern
sunspot
had become more asymmetrical and the northern follower had reduced in
size. The
number of pores had also reduced. On subsequent days the group
continued to
decay such that on the 4th it was of type Csi with an area of 60
millionths but
still highly tilted. When last seen on the 5th just a single Axx
sunspot remained
(no observations were made on the 6th and 7th when the group would have
been
close to the western limb).
On
the 4th and 5th a Dso group
was seen close to the eastern limb – this was AR 2542 at
11°N/358°. By
the next observation
on the 14th it was
approaching the western limb still of type Dso with an area of 160
millionths. A
single Hsx sunspot
was all
that was seen of this group very close to the limb on the 16th. One of
the
other five groups on the 14th and near the central meridian was of type
Csi
with many pores following a small penumbral leader – this was
AR
2544 at 21°N/295°.
By the 16th the leader penumbral sunspot had grown from 30 to 130
millionths
but there were fewer followers. When
last seen on the 17th, the group, still of type Cai was reduced at 70
millionths and again few pores being present.
The
14th also showed a moderately
sized group, AR 2546, close to the eastern limb at
7°S/223° and
of type
Hhx. On the 16th it
had an
estimated
area of 370 millionths before slowly increasing to 650 millionths on
the 23rd.
Thereafter it slightly reduced to 530 millionths on the 24th and it was
last
seen close to the western limb on the 26th. It remained of type Hhx on
all
observing days and it was the only group seen on the 22nd, 23rd and
24th. AR 2546 was
seen with
the protected
naked eye
on the 17th, 22nd, 23rd and 24th.
The
last observation of the month, on the 29th, only showed two small Hsx
sunspot
groups.
Hydrogen Alpha:
Prominences were fairly small
based on 9 observations. An anvil prominence was seen on the W limb on
the 23rd
while on loop prominence was seen on the SW limb on the 28th where part
of the
prominence extended onto the disk.
On
the
29th two arch prominences were seen on the W limb.
The
number of filaments was quite variable
with none on the 1st to more than 10 on the 22nd and 23rd before
reducing again
towards the end of the month. Some extended filaments were seen on the
22nd,
23rd and 27th.
On
the 22nd a flare was seen to
the west of the moderately sized AR 2546 (the sunspot umbra was easily
seen in
Hα). At the start of the observing period at 09:15 UT a
bright
compact blob was
seen together with a slightly fainter elongated bright region to its
west. Over
the next 15 minutes the elongated region faded to leave two smaller
brighter
regions. The
compact blob also
reduced
in brightness during these 15 minutes.
NOAA
indicates that this was a B5.9 flare peaking at 09:21
UT. During
the same observation an extensive region of plage was seen to the east
of AR
2546. Plage was also seen around AR 2546 on the 15th, 16th and 23rd.
Images:
The white light images below of AR
2536 from the 1st and AR 2546 from the 17th were taken with a 105mm ETX
telescope, Baader N3.8 Solar Film and Imaging Source Camera. The AR
2546 image was
taken under poor seeing conditions with a solar altitude of 10°
and
image
scaled at 75% of the image of AR 2536.
June
2016
There
was quite a reduction in
activity compared to recent months and the lowest since May 2010. No
sunspots were seen during the beginning
and end of the month – in particular for observations between
the 4th and 7th
inclusive, between the 24th and 28th inclusive and the 30th.
The
first
observation
with
sunspots was on the 8th with the appearance of AR 2552 at
16°N/358° of type Cro
having appeared on the solar disk. By the following day this group had
developed into an irregular Hax penumbral sunspot of size 120
millionths which
included several umbrae. On the 12th another group has developed in the
western
hemisphere – AR 2554 of type Dso at 8°N/316°
and area 110 millionths. The only
other group on the 12th was AR 2553, an asymmetrical penumbral sunspot
of type
Hax at 6°S/226° with an area of 230 millionths. On the
15th AR 2554 was close
to the western limb while AR 2553 was approaching the central meridian
with a
similar appearance and size. AR 2553 was seen again on the 19th to 21st
still
type Hax and of a similar size. Also
on
the 19th were AR 2558 at 12°N/215° of type Dai and size
70 millionths and AR
2556 of type Hax at 5°N/135° and area 90 millionths. AR
2558 had disappeared by
the following day while AR 2556 started to reduce in size as it
approached the
central meridian. On the 21st, the last observation with sunspots, AR
2556 was
just 30 millionths in size.
Hydrogen Alpha:
No particularly large prominences
were seen based on 12 observations. The most striking were a NW limb
arch
prominence on the 4th and a ‘smoking chimney’
prominence on the 25th on the E
limb. Many filaments were seen on most observations during the month,
especially in the northern hemisphere. Of particular note was a string
of
filaments forming a semi-circle on the 29th in the eastern hemisphere.
Plage
was seen around AR 2552 on the 9th, around AR 2256 on the 20th and near
the
eastern limb on the 26th (no sunspot group present).
July
2016
There
was an
increase in
activity
compared to the previous month but there were still several spotless
days at
the beginning and end of the month.
Between
the 1st and 6th
inclusive only one groups was seen on the 3rd
only – an Axx sunspot near the centre of the disk at
11°N/°9. Observations on
the 25th, 26th and 31st also showed spotless disks.
On
the 16th four groups were seen
including two nearby groups AR 2565 and 2567: these were at
5°N/175° of type
Cao & size 170 millionths and at 6°N/165° of
type Dac & size 270
millionths (the other two groups were of type Axx and Bxo). AR
2565 increased in size slightly over
subsequent days such that it was 340 millionths on the 19th and still
of type
Cao. With this
group
approaching the
western limb on the 22nd and 24th it was of type Hax.
AR
2567 also increased in size to 340
millionths on the 18th when it was of type Dkc with several pores
between the larger
leader and a couple of follower penumbral sunspots. It then continued
to grow
through the leader between the 19th and 20th to 600 millionths
– the group was
now of type Dkc. The two followers had also merged. Subsequent
observations
showed that AR 2567 reverting back to type Dac and it was seen close to
the
limb on the 24th. A
single Axx sunspot,
AR 2566, was seen to the north of AR 2565 on the 18th only. One
protected naked
eye sunspot was seen on the 16th (AR 2567) and two on each day between
the 17th
to 20th (AR 2565 and 2567).
Hydrogen Alpha:
No particularly large prominences
were seen based on 11 observations. The most striking were a arch type
on the NE
limb on the 18th,a bright short prominence on the W limb on the 24th
and
combined prominence/filaments all on the NW limb on the 20th, 23rd and
24th
(the latter two being the same feature).
Numerous
quite long
filaments were seen on the 2nd and 3rd all in the
northern hemisphere. A
long broken
filament was seen, again the northern hemisphere on the 24th, 25th and
31st. Plage was
seen around
combined AR
2565 and 2567 on the 17th, 18th, 19th, 20th, 22nd and 23rd. Plage was
also seen
at three other locations without sunspots on the 17th and two of these
on the
18th.
Images:
The white light images below of AR 2567 (left) and AR 2565 (right) from
the 17th and
23rd were
taken with a 105mm ETX telescope, Baader N3.8 Solar Film and Imaging
Source
Camera.
August
2016
Although
overall
activity was at
its highest since 2016 February, there were no notable sunspots groups.
Based
on 25 observations there was only one spotless day on the 3rd. The
northern hemisphere was the more dominant
while in the southern hemisphere there were several days without any
sunspots.
One
of the two groups seen on the
4th was AR 2571 at 14°N/268° of type Axx. It was of
type Bxo on the 5th before
developing into a small compact Dsc group on the 7th with an area of 90
millionths when near the central meridian. When last seen on the 9th
the two
leading penumbral sunspots had merged while the following sunspots had
almost
disappeared to leave a Cao group of area 100 millionths. On
the 8th a group with an extended
latitudinal extent had appeared around the eastern limb –
this was AR 2574 at 5°N/172°.
It had an irregular penumbral sunspot to the north and a more regular
penumbral
sunspot to the south. Observations on the 9th and 12th showed AR 2574
of type
Dao and area 160 millionths. As AR 2574 progressed across the disk, the
northern sunspot reduced in size and became more circular in size.
Hence on the
17th it had an area of 80 millionths while it was last seen on the
following
day as just two similarly sized small penumbral sunspots. By
the 12th AR 2574 was accompanied by a
following group at a similar latitude.
This was AR 2577 at
4°N/164° of type Csi and size 30 millionths. It
obtained a size of 90 millionths and type Dao on the 13th before being
last
seen on the disk as a type Axx group on the 17th. During the period 9th
to 18th
a southern group, AR 2576 was seen. This was of type Hax and area 100
millionths on the 12th before developing a couple of follower spots on
the 14th
and then reducing to a pair of close small penumbral sunspots on the
18th.
On
the 20th only one group was
seen – AR 2578 at 10°N/87° of type Cso and
area 30 millionths. It had
disappeared by the 22nd when the larger of two groups was AR 2579 at
12°N/34°
of type Dsi with an area of 60 millionths. Subsequent observations
showed that
this group decaying as it passed through the central meridian and it
was last
seen as an Axx group on the 26th. AR 2581 had formed in the disk
between the
25th and 26th as a small Cso group at 14°N/337°. The
leader penumbral sunspot increased in
size such that by the 27th the group had an area of 120 millionths.
Although
the leader became more symmetrical as it progressed across the disk, it
was
still of a similar size when last seen on the 31st.
One
of two new groups that
appeared near the eastern limb on the 31st was AR 2585 at
8°N/222° of type Dkc.
It comprised of an irregular leader penumbral sunspots and two follower
penumbral sunspots – a promising group for September.
Hydrogen Alpha:
A few isolated prominences were
seen on a small section of the NE limb on the 6th but on the following
day
these had developed into a curtain of prominences stretching for some
20° along
the limb. All were of a similar height with only a few breaks between
the
numerous prominences. On both dates a broad filament almost parallel to
these
prominences was also seen but not quite as long.
A
thin spike prominence was also seen on the
W limb which on the 7th appeared to be detached from the limb.
A
fine wispy prominence was seen
on the 15th extending above the NE limb. It comprised of several parts
and it
had an estimated height of about 220,000 km. Another notable feature
was a
combined prominence and filament seen on the 30th and 31st on the NE
limb. On
the 30th only a small portion of this was seen as a prominence and the
rest as
a thin filament extending. By the 31st no prominence was seen and there
was a
gap between the filament and the limb caused by solar rotation.
Plage
was seen around combined AR
2570 and 2571 on the 6th and 7th around AR 2574 on the 12th, 14th and
15th and
around AR 2581 on the 27th, 30th and 31st.
September
2016
There
was a
slight
reduction in
activity compared to the previous month and once again the northern
hemisphere
was the more dominant with no sunspots in the south on 9 or the 12
observing
days.
The
highlight group of the month
was AR 2585 initially seen close to the limb on August 31 as a Dkc
group at 8°N/222°.
By
the 3rd it was of type Eac with an area of
500 millionths comprising four irregular penumbral spots and a few
pores – the
largest sunspot was the leader. By the following day two of the
follower
sunspots had merged to form the largest sunspot and the change the
group to
type Ekc. When next seen on the 7th AR 2585 was just past the central
meridian
when it consisted of two penumbral sunspots and a few pores –
the irregular
follower was still the largest sunspot – the total area had
reduced to 380
millionths. On the 8th the follower became more irregular which became
much
smaller and had split into two when AR 2585 was last seen near the limb
on the
11th. AR 2585 was seen with the protected naked eye on the 3rd, 4th,
7th and
8th. A small Axx group was seen following AR 2585 on the 3rd and 4th
– this
being AR 2587 at 10°N/212°.
During
the period 3rd to 11th the
other five groups seen (i.e. in addition to AR 2585 and 2587) were all
small. No sunspots
were seen
on the
15th. On the 18th three groups were seen.
One of these was AR
2593 of type Axx at 8°N/47°. When next seen on the
21st it was bipolar of type Dsi with an area 60 millionths with a few
pores
seen in addition to the small symmetrical leading and following
penumbral
sunspots. By the 23rd it was if type Csi comprising a small leading
penumbral
sunspot and a fan shaped collection of following pores. On the
following day AR
2593 was of type Bxo approaching the western limb. Also on the 23rd a
southern small
group, AR 2597, had developed on the disk of type Cai at 13S/347 and
area 90
millionths (it was not seen on the previous day). It was of the same
type on
the 24th while by the last observation of the month on the 25th it had
become
type Dac with an area of 100 millionths.
Hydrogen Alpha:
On the 8th a long filament was
seen stretching across the northern hemisphere where the southern edge
was
quite irregular in shape. On
the 11th a
complex prominence was seen on the western limb – several jet
of hydrogen were
seen. Further to
the south a
small
detached prominence was seen. On
the 23th
a combined filament & prominence was seen on the SE limb
– the prominence
part was quite short and the whole structure was quite thin in shape.
Plage was
also seen around AR 2593. Another complex prominence was seen on the
25th.
Images:
The white light images below of AR 2587
(left) and
AR 2585 (right) from the 3rd was taken with a 105mm ETX telescope,
Baader N3.8
Solar Film and Imaging Source Camera.
October
2016
There
was a
further slight
reduction in activity compared to the previous months and once again
the
northern hemisphere was the more dominant with no sunspots in the south
on all
7 observations made in the latter half of the month.
The
first observation, on the
2nd, showed no sunspots. On
the 3rd one
group, AR 2598 developed on the disk while another, AR 2599 appeared
around the
eastern limb. AR
2598 at 14°N/175°
was
initially of type Cai before developing into type Dso on the 4th and
then Dai
on the 6th when it comprised of two irregular penumbral sunspots and
several
pores to the south; the total area was 140 millionths. When next seen
on the
9th AR 2598 was of type Cai with a string of pores following the
penumbral
leader which had an area of 100 millionths.
On the 11th and approaching the western limb only a
single
Axx sunspot
was seen. AR 2599,
the largest group
seen during the month, was an irregular penumbral sunspot of type Hkx
on the
4th, 5th and 6th at 14°S/146° and with an area of 300
millionths on the 6th. By
the 9th AR 2599 was near the central meridian and the main sunspot had
almost
split and small following penumbral sunspots developed to form a Dki
group of
area 270 millionths – it was also seen with the protected
naked
eye. By the
11th AR 2599 was of type Cao with the surrounding pores disappearing by
the
13th to give a Hax group with area 200 millionths.
This group was last seen on the 15th very
close to the western limb.
Three
other groups were seen
during the first half of the month – the largest of these was
AR
2600 at 12°N/104°
as an Hax or Hsx sunspot which attained a maximum area of 150
millionths on the
15th. During the
second half of the
month only one or two groups were seen on each observation. The largest
of
these was AR 2603 at 13°N/337° which obtained an area
of 100
millionths when it
was of type Dso and approaching the western limb.
Hydrogen Alpha:
On the 2nd a quite dynamic
prominence was seen on the SW limb while further down the limb a
combined
prominence/filament was seen, the majority of which was on the disk.
Other
prominences from another three observations were small but included an
inverted
v on the W limb on the 23rd. The
15th
showed interesting filaments including a string of filaments near the
NE limb
and a curvy m shaped to the north of AR 2602. Plage was seen around ARs
2599
and 2602 on the 15th, around AR 2603 on the 22nd and 23rd.
November
2016
Activity
was at a similar level
to last month. The first observation of the month, on the 2nd, showed
no
sunspots. The six groups seen from observations on the 3rd, 6th and
11th were
all small.
One
of the two groups seen on the
13th, AR 2610 at 15°N/16°, was of type Cai and area 60
millionths. When next
seen on the 17th this group had developed into a bipolar Dai group of a
similar
size. By the following day it had reduced to a Cao type and it was not
seen on
the 19th, when the two groups seen were of type Cso (area 40
millionths) and
Axx.
The
next observation on the 25th
showed a single group, AR 2612, at 9°N/194° of type Dao
and area 260 millionths
– the largest group of the month. The two penumbral sunspots
were close to each
other on the 25th and 26th before merging when seen on the 28th as an
elongated
penumbral sunspot with a couple of following pores.
These followers had disappeared by the 29th
when the group was just past the central meridian. On the 30th the
following
part of the penumbral sunspot had separated to give a Dao group once
again. The
two other groups seen on the 29th and 30th were AR 2614 at
6°N/165° of type Dao
and area 130 millionths and AR 2615 at 7°S/134° of type
Dso and area 110
millionths.
Hydrogen Alpha:
Although prominences were seen on
the 4 observations, none were particularly striking except for a small
detached
spike prominence above the SE limb on the 6th. Filaments were more
numerous as
the month progressed, especially on the 26th were many extended but
broken
filaments were seen with the majority being in the northern hemisphere.
Plage
was seen around ARs 2609 & 2610 on the 13th and around AR 2612
and an Axx
sunspot at 10°N/295° (no AR number) on the 26th.
December
2016
There was reduced
activity
compared to the last few months with two of the six observations being
spotless
(on the 11th and 26th). On
the 3rd and 4th
AR 2612 was seen approaching the western limb at
7°N/193° of type Dso and area
90 millionths on the 3rd and type Axx on the 4th. The other group seen
on these
dates was AR 2615 at 6°S/137° and near the central
meridian – this group was of
type Dai and area 110 millionths on the 3rd and type Dsi and area 200
millionths on the 4th. AR 2615 was bipolar in form with a few pores
between the
leader and follower. On the 22nd only a single Axx sunspot was seen at
19°S/310°
(AR 2620). Two small groups developed on the disk on the 27th: AR 2621
at 12°N/235°
of type Dso and area 90 millionths and an Axx sunspot at
13°N/185° (no AR
number).
Hydrogen Alpha:
Based on the four observations,
none of the prominences or filaments were particularly striking. On the
4th all
the filaments were in the northern hemisphere including small filaments
around
AR 2612. On the 26th many small filaments were seen together with a
combined
prominence/filament on the eastern limb – this was seen just
a filament after
been rotated onto the disk by the following day. Plage was seen around
AR 2621
and near the western limb on the 27th.
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created on 24 January 2016.
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