Solar Observations for October 2017
Every day I attempt to view the sun using a safe solar filter telescope from Maroubra in Sydney. The American Association of Variable Star Observers and British Astronomical Association receive my observations and add them to the work of other researchers who are also observing our closest star from other locations on the planet. I present my solar activity findings each month at the Sydney City Skywatchers meeting and hope to see you there!
On the first of October the 3 groups of Sunspots seen at the end of last month were still visible on the solar disc, these were a single Hsx (10) spot in AR12681, another Hsx spot in AR12682 and a Cki (39) group in AR12683.
No further observations were made until the 4th due to bad weather and at that time only 2 groups remained; an Hsx spot in AR12682 and a Csi (12) group in AR12683. No Prominences could be seen on that day except for a large Filament close to the spot in AR12682 and a smaller one close to the group in AR12683.
On the 7th the only Sunspot that remained on the Sun was a Hsx spot in AR12683. You can see this in the diagram below.
From the 8th to the 15th October the solar disc was clear of all Sunspot. On that day a single Axx (1) spot was observed in AR12684. Again on the 16th no Sunspots could be seen until the 21st.On that day a single Hsx spot emerged round the south eastern limb in AR12685 and on the 23rd another single Hrx (4) spot was seen close to the north eastern limb. These two single spots were the only ones remaining on the sun until the 29th. No further observations were made for the month due to cloud cover.
PROMINENCES.
Prominence activity remained fairly small & constant, though once again mostly faint. On the 6th a double Arched Prominence stretched across the north western limb for approximately 233,00km. On the north eastern limb a single Arch Prominence reached a height of about 37,000km. A triple Arched Prominence was observed on the 7th on the south eastern limb reaching a height of about 46,000km.
All Prominences until the 14th remained small and faint when a single Arched Prominence on the southwestern limb reached a height of about 84,000km. You can just see this in my photograph below.
On the 15th it could still be seen and looked like an overhanging tree. Very few Prominences could be observed until the 18th. A large single Arched Prominence emerged round the north eastern limb and by the 20th it had grown to a height of approximately 65,000km and 270,000km across the limb.
Further Prominences remained very faint and small for the rest of the month.
FLARES
No Flares were seen for the whole month of observations.
SUMMARY
For the month of October 2017 all activity once again on the Sun remained extremely low.
A total of 19 Observations were made for the month with the remaining 12 days being cloud covered and/or rain.
A total of only 6 groups were observed. This included 3 groups in the north and 3 in the south, comprising of 4 spots in the north and 4 spots in the south giving a total of 8 Sunspots.
This is the lowest Sunspot count since 2011.
The average Relevant Sunspot number for the month was 11 and the average CV was 9.2
Most Prominences observed once again were quiet faint.
No CMEs or Flares were observed.
Monty Leventhal OAM.