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
2019
The
first observations of the
month on the 17th and 19th showed blank disks. The next observation on
the 27th
showed a Cso group nearing the western limb – this was AR
2733 at 8°N/259°
which comprised the leading penumbral sunspot and a string of
followers. When
seen on the following day, the number of followers had reduced and it
had an
area of 50 millionths. The final observations of the month on the 30th
and 31st
again revealed blank disks.
Hydrogen Alpha:
The two Hα observations during
the month on the 17th and 20th showed just small prominences (no
filaments or
plague).
February
2019
No
sunspots were seen during the
month based on 17 observations. Faculae was seen near the western limb
on the
24th and 25th.
Hydrogen Alpha:
Hα observations remained low during
the month based on 6 observations – the most notable feature
was an extended
filament in the northern hemisphere on the 21st.
Plague was seen on the 23rd near the western
limb (to the south of the now smaller filament from the 21st). No
prominences
were seen.
March
2019
From
15 observations during the
month four groups were seen on 8 days and blank disks on the remaining
7 days.
All the groups were seen in the northern hemisphere. The first of these
was AR
2734 at 8°N/62° which was initially seen on the 5th as
an Axx group comprising
a collection of small sunspots. By the 7th, with the group approaching
the
central meridian, AR 2734 appeared as a small Cao group with an area of
30
millionths. The followers had disappeared by the 9th to leave a Hax
group of
the same area. As AR 2734 was seen progressing towards the western limb
it
decayed to type Axx on the 10th and 11th. The next observations on the
14th and
17th both showed blank disks.
On
the 18th AR 2735 was seen at 2°N/257°
of type Cso with an area of 30 millionths. By the next observations on
the
24th, AR 2734 was not seen but another group, AR 2736 was seen close to
the
western limb as a Dso group at 12°N/279°. Only faculae
remained on the
following day - the observations on the 25th, 26th, 28th, 29th and 30th
were
all blank. On the
31st a Bxo group had
developed in the north-east quadrant at 12°N/59°
– this was the fourth group of
the month, AR 2737.
Hydrogen Alpha:
Very
few Hα features were seen during the month.
On the 9th plage was seen associated with AR 2734 but not on the 10th.
A curved
prominence was seen on the W limb on the 10th. Two small filaments were
seen on
the 17th while on the 24th plage was seen associated with AR 2736 close
to the
W limb and another region nearer to the middle of the disk. No features
were
seen on the 30th. On the 31st plage was seen associated with AR 2737.
April
2019
On
the 1st AR 2737 was seen at 11°N/61°
type Dso with an area of 70 millionths. By the 4th this group had
disappeared
on the disk and no sunspots were seen as was also the case on the 5th.
The
next observation on the 9th
revealed a moderately sized single penumbral sunspot with two umbra at
6°N/298°
of type Hhx and area 280 millionths (AR 2738). On the 10th two small
pores were
seen following the main sunspot but these had disappeared by the 11th.
On the
13th and 15th a light bridge could be seen within the penumbra and
following
pores on the 13th. On the 16th the sunspot had an area of 430
millionths and a
single umbra. Its form remained the same as it progressed towards the
western
limb – it was last seen on the 19th together with faculae. AR
2737 was seen
with the protected naked eye on each observation between the 10th and
17th
inclusive.
On
the 17th a Bxo group had
developed on the disk just past the central meridian.
This was AR 2739 at 6°N/259°. On the
following day it had developed into a small Dso group with area 50
millionths
while on the 19th it was type Cso. It appeared as an Axx sunspot on the
20th
before disappearing by the 21st when there was a spotless disk. There
were
further spotless disks on the 22nd, 25th, 26th, 29th and 30th.
Hydrogen Alpha:
The
main Hα activity was plage and umbra
associated with the passage of AR 2738 on the 10th, 11th and 15th. Two
moderately sized prominences were also seen on the 10th, the base of
one of
these being above the limb. Observations made during the latter part of
the
month were devoid of any Hα features.
May
2019
Observations
on the 1st and 2nd
showed spotless disks. The next observation on the 4th revealed an Hsx
sunspot
near the eastern limb at 8°N/305° (AR 2740) –
this was the return of AR 2738.
As this group progressed towards the central meridian, the penumbral
sunspot
was asymmetric and it was accompanied by several nearby pores. It
obtained an
area of 90 millionths on the 10th. From the 11th onwards it reduced in
size
such that it was of type Cso on the 11th and 12th with an area of 30
millionth
and then became type Axx on the 13th and 14th. AR 2738 was not seen on
the 15th
when it would have been close to the western limb.
On
the 7th another Hsx sunspot
was seen near the eastern limb – this was AR 2741 at
6°N/270°. This was larger
and more symmetrical than AR 2740 having an area of 210 millionths on
the 9th
and 10th. It was accompanied by pores on the 11th only when the umbra
also
split into two. AR 2741 remained type Hax as it progressed towards to
western
limb.
The
10 observations made from the
20th all showed blank disks.
Hydrogen Alpha:
The
passage of AR 2741 was marked by the
presence of plage, filaments and sunspot umbra as main Hα
activity during the
month (from the 10th to the 15th). A combined prominence/filament was
seen on
the NE limb on the 4th. A
prominence was
seen at a similar location on the NW limb on the 13th, 14th and 15th.
Other
small prominences were seen on the 16th, 25th, 26th, 27th and 31st. A
small
region of plage was seen near the E limb on the 25th.
June
2019
No
sunspots were seen during the
month based on 15 observations.
Hydrogen Alpha:
Hα activity remained low but
there were a few prominences and filaments. A small mound prominence
was seen
on the NW limb on the 1st while two spike prominences were seen on the
E limb
on the 3rd. Also on the 3rd several filaments were seen near the E
limb. On the
6th a curved multi-segment filaments was seen in the NE quadrant.
Smaller
filaments were seen on the 8th and 9th. Small prominences were seen on
the
14th, 15th, 22rd, 27th and 28th. Two ‘blob’ shaped
filaments were also seen on
the 28th.
July
2019
For
the 15 observations made
between the 11th and 30th only one showed any sunspots.
This was on 22nd only when a single Axx
sunspot was seen at 3°N/80°.
Hydrogen Alpha:
Hα
activity also remained low with a few
prominences and filaments (based on 7 observations). Prominences were
seen on
the 20th and 29th with, for the latter date, a detached prominence
above the NW
limb and a spike prominence on the NE limb.
Small filaments were seen on the 14th, 21st, 26th,
28th and 29th. No Hα features
were seen at all on the 12th.
August
2019
Based
on 18 observations made
between up to the 26th, only one observation included a sunspot. This was on the 7th when
AR 2747 was seen at
N07°/201° as a single Axx sunspot.
Hydrogen Alpha:
As
for previous month Hα activity remained low with
a few prominences and filaments (based on 14 observations). Prominences
were
seen on the 19th, 20th and 23rd with, for the latter date, a flame
prominence
above the SE limb. Small
filaments were
seen on the 24th and 25th.
September
2019
No
sunspots were observed from 20
observations from the 4th to 28th.
Hydrogen Alpha:
Once
again very little Hα activity was observed
from 9 observations. Small
filaments
were seen on the 4th, 5th and 21st.
A
small prominence was seen on the SE limb on the 14th and 15th. A more
extensive
prominence was seen on the S limb on the 20th while another small
prominence
was seen on the SW limb on the 28th.
On
several days no Hα features were observed.
October
2019
No
sunspots were observed from 10
observations from the 2nd to 31st. Faculae were observed near the
south-east
limb on the 2nd.
Hydrogen Alpha:
The Sun was observed in Hα just
on one day – the 5th when a small filament and a small region
of plage were
observed.
November
2019
No
sunspots were observed from 11
observations between the 3rd and 30th. Faculae was seen near the
south-east
limb on the 13th and 14th (and Mercury on the 11th).
Hydrogen Alpha:
No Hα features were observed on
each of 5 observations throughout the month (3rd, 9th, 10th, 29th and
30th).
December
2019
Six
observations between the 8th
and 23rd were all spotless. On
the 24th
a Bxo group comprising two sunspots was seen at
32°S/120° (AR 2753).
This group was seen on the following day
together with another new cycle group AR 2754 at
26°N/191° (type Axx).
The final observation of the month on the
30th was also spotless.
Hydrogen Alpha:
The
Sun was observed in Hα on six days.
On the 8th and 23rd small filaments were
seen, no features were seen on the 11th, a small prominence was seen on
the
15th, plage was seen associated with AR 2453 & 2454 on the 24th
and finally
plage associated with AR 2543 was
seen on the 30th.
Page
created on 11 November 2020.
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