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Solar Observations for May 2017

Monty Leventhal (pictured right on his balcony in Maroubra) is a regular solar observer who reports his observations daily to many organisations around the world. This is his monthly summary for May 2017.

Once again activity on the Sun continued to be very low. Only a single Axx spot was seen on the 1st of May in Active Region 12653. No further observations were made until the 4th due to cloud cover and on that day 2 small groups were seen, one a Cso group in AR12654 and the other a small Bxi group in AR 12655, both in the northern hemisphere. By the 6th the group in AR12655 had disappeared and the group in AR12654 was last seen on the 7th as a single Axx spot.

Since then no spots could be seen on the Sun until the 16th when a single Axx spot was observed close to the NE limb in AR12656. By the 17th it had developed into a small penumbral Hrx spot.

Due to bad weather no observations were made until the 20th when 2 single spots were seen, one being a single Hsx spot in AR12656 and the other a single Axx spot in AR12658. Another small Bxo group of spots appeared on the solar disc in AR12659 on the 21st and another Bxi group appeared in AR12660 on the 22nd. By the 23rd the next day all that remained was a single Axx spot and a single Hsx spot in AR12659

On the 24th the single Hsx spot had grown to a much larger Dsi (28) group and the following day had shrunk to a Cai (9). This remained a solitary group on the solar disc until 28th when it was last seen close to the NW limb .

The Sun was clear of Sunspot on the 29th and on the 31st only a single Axx spot was observed in AR12660 very close to the NE limb.


Most prominences on the Sun were seen during every observation but small and faint, though some were of most interest. These occurred on the 4th. An active Prominence on the NW limb reached a height of 56,000km, a Single Arch on the 5th, height about 47,000km, another on the 15th, height about 56,000km.

On the 16th a broken Column type Prominence reached an approximate height of 130,000km.


Only 2 Flares were seen during the month. The first was a type 1F flare on the 28th May in AR12659 (as seen in the diagram above). It started at 23.10 hrs UT, peaked at 23.20 & ended at 23.45. It had an X-ray class of C1. The second one was seen on the 31st. It was a type 2B (recurring) Flare. I started at 22.20, peaked at 23.15 & ended at 23.50 (as seen in the diagram below). This type 2B Flare was seen on the NE limb of the Sun and appeared to have emanated from a group of spots just around the limb. It had an X-ray class of 2C.

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