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  • Monty Leventhal OAM

Solar Observations for July 2017

Every day I observe solar activity and publish my results globally. I also report my monthly findings at the Sydney City Skywatchers meeting on the first Monday of the month. Unfortunately very low activity on the Sun continued throughout July. On the 1st only a single Hax (7) spot could be observed in AR12664, also a Filament in the NE quadrant.

The solar disc was clear of all Sunspots on the 3rd & 4th. On the 5th a new single Hsx (10) spot was observed close to the eastern limb in AR12665. Close to it a Sub Flare was seen right on the eastern limb at 22.50. It peaked at 22.55 and ended at 23.10, it had an X-ray class 0B. By the 7th this group had grown to a CV of Dki (46) and on the 8th produced a strong type 3B Flare. It started at 03.10UT on the 9th, peaked at 03.20 and ended at 04.00. It had an X-ray class of M1.3. You can see this in the photograph above.

This Flare occurred during my outreach time at the Sydney Observatory and many visitors had the opportunity to view this exciting activity on the Sun.

The group of Sunspots in AR 12665 grew even larger on the 9th with a CV Eki (47). It produced a type 2B Flare. It started at 00.00hrs on the 10th, peaked at 00.40 and ended at 01.00. It had an X-ray class of C-1.5.

The group in AR12665 continued to the western limb with the rotation of the Sun and could no longer be seen on the 17th with the solar disc now clear of all Sunspots until the 29th.

A further Flare type 2N did occur on the 18th on the SW limb (shown in my photograph above). It started at 22.20 UT, peaked at 00.10 on the 19th ended approximately at 00.40. The actual end of this Flare could not be seen as it had rotated round the SW limb.

On the 29th a small Bxo (2) group of spots were seen in the NE, AR12669. They had disappeared by the following day. On the 31st again the solar disc was clear of all Sunspots. A small type 1B Flare was observed on the SE limb. It started at 22.15, peaked at 22.30 and ended at 22.45. It had an X-ray class of B4.


Though Sunspot activity was very low Prominence activity remained fairly constant though mostly faint.

A Single Arch prominence on the 3rd reaching 56,000km high; a Mound type reaching 74,000km on the 4th; an Unconnected Arch on the 8th reaching 75,000km; on the 17th a Single Arch on the NW reaching 93,000km.

Most others for the rest of the month were small and faint.


For the month of July 2017 all activity once again on the Sun remained very low.

A total of 26 Observations were made for the month with the remaining days being cloud covered and/or rain.

A total of only 5 groups were observed. This included 4 groups in the north and 1 in the south, comprising of 9 spots in the north and 15 spots in the south.

The average Relevant Sunspot number for the month was 9 and the average CV was 14.2.

Most Prominences observed once again were quiet faint.

Monty Leventhal OAM



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