Solar Section        

September 16, 2017

A short Summary of Carrington Rotation 2194

Carrington Rotation 2194 covered the time period from 2017-08-16 1126 UT – 2017-09-12 1729 UT.
488 Submissions were added to ALPO’s Solar archive at the time of this summary, while the activity of the Sun dramatically increased. They can be viewed in ALPO’s Solar Archive for CR2194:
http://www.alpo-astronomy.org/gallery/main.php?g2_itemId=104412
The rotation started with one active region covering an area of 170 millionths and a Wolf Number of 21, and ended with two regions covering 420 millionths and a Wolf Number of 38. The Total Active Region Area, during the rotation was a whopping 12 times that of the previous rotation. This was mainly due to a burst of activity during a seven day period in which the Sun produced 7 flares, which caused R2 alerts to be issued. In addition to 3 flares larger than an M5.0, four X-class flares were detected, an X2.2 and X9.3 on 9/6, an X1.3 on 9/7, and finally an X8.2 on 9/10. The X9.3 flare is the largest flare since I started recording high solar activity almost four years ago, and possibly the largest of the current cycle. Noteworthy here is that we have not had an R2 triggering flare in 5 months, but have had 91 spotless days already since Solar Maximum. During the rotation we could observe 10 regions AR2671 – AR2680, of which AR2679 lasted only two days. The rotation started relative quiet for its first half but then activity increased rapidly with AR2673 and AR2674. AR2673 covered the largest Active Region Area on 9/9 with 1060 millionths, which also coincides with the largest Total Active Region Area for the Sun of the rotation with 1760 millionths. The highest Wolf number 122 was shared on two days 9/5 and 9/6. There were no spotless days during CR2194.
For this Rotation we would like to feature three images by three of our observers, Mike Borman, Christian Viladrich, and a composite by Guilherme Grassman, who managed to capture part of the X9.3 flare on 9/6. Thanks to them, as well as all other contributors for another great rotation. Please take a look at their images by clicking on the link above linking to our archive for CR2194.
Clear Skies,
Theo Ramakers
Acting Assistant Coordinator, the ALPOSS

September 14, 2017

ALPOSS – A report on Carrington Rotation CR2184 through CR2187

The next article on Solar Activity by ALPOSS Coordinator and Scientific Advisor Richard Hill covers his analysis of the activity of the Carrington Rotations: CR2184 thru CR2187, or November 16th 2016 through March 6th, 2017. The reports are based on 1200 reports and image submissions of numerous contributors to the Solar Observations Archive. The report was published in the 2017 Summer issue of the ALPO Journal, the Strolling Astronomer, and can now also be accessed as a stand alone document on ALPOSS Solar Observations & Reports page, or downloading it by “right” clicking on the picture below.

September 12, 2017

ALPOSS – A report on CR2180 through CR2183

We are continuing to post here the reports written by ALPOSS Coordinator and Scientific Advisor Richard Hill. This post contains his analysis of the solar activity of the Carrington Rotations: CR2180 through CR2183, or July 30th through November 16th, 2016. The reports are based on 1933 reports and image submissions of numerous contributors to the Solar Observations Archive. The report was published in the 2017 Spring issue of the ALPO Journal, the Strolling Astronomer, and can now also be accessed as a stand alone document on ALPOSS Solar Observations & Reports page, or downloading it by “right”clicking on the picture below.

August 30, 2017

A short Summary of Carrington Rotation 2193

Carrington Rotation 2193 covered the time period from 2017-07-20 0606 UT – 2017-08-16 1126 UT.
Solar Activity decreased again, and so did the number of submissions. 281 Submissions were added to the archive at the time of this summary, and can be viewed in ALPO’s Solar Archive for CR2193:

The Solar activity, in terms of total active region areas, during the rotation was only approx. 1/6 of the previous rotation. During the rotation we could observe 4 regions AR2668 – AR2671, of which AR2667 lasted only one day. The rotation started with a spotless period of 10 days, interrupted for 1 day on 7/26 with a small 10 millionths’ region AR2668. Another small region AR2669 popped up for two days on 7/30 and 7/31 followed again by two spotless days on 8/1 and 8/2. That’s when AR2670 came around the Eastern limb with 160 millionths on 8/3 which was the largest daily area during the rotation. The highest Wolf number 13 was shared on three days from 8/4 to 8/6 and the total spotless day count for the cycle stands at 91. The rotation ended the first day when the region AR2671 started to come around the Eastern limb.
For this Rotation we would like to feature three images by three of our observers, Dave Tyler, Monty Leventhal, and Howard Eskildsen. Thanks to them, as well as all other contributors, for another great rotation. Please take a look at their images by clicking on the link above linking to our archive for CR2192.
Clear Skies,
Theo Ramakers

August 27, 2017

A short Summary of Carrington Rotation 2192

Carrington Rotation 2192 covered the time period from 2017-06-23 0117 UT – 2017-07-20 0606 UT.
Solar Activity increased again, and so did the number of submissions. 495 Submissions were added to the archive at the time of this summary, and can be viewed in ALPO’s Solar Archive for CR2192:

During the rotation we could observe 5 regions, one of which, AR2667, lasted only one day. The rotation started on 2017-06-23 with 2 Active Regions and a Wolf number of 23. The total Active Region Area was 80 millionths. The highest Wolf Number of 58 was reached on 2017-07-23, while AR2665 was the dominant Active Region. AR 2665 also claimed to be the largest Active Region area for the rotation on 7/10 with 710 millionths (a coincidence?). The rotation had a period of 3 spotless days 0n 7/4 and 7/5 as well as a single day on 7/19, bringing the total spotless days since Solar Maximum to 80. The rotation ended with a spotless Sun.
For this Rotation we would like to feature three observations by three of our observers, Tony Broxton, Monty Leventhal, and Joe Gianninoto. Thanks to them, as well as all other contributors, for another great rotation. Please take a look at their images by clicking on the link above linking to our archive for CR2192.
Clear Skies,
Theo Ramakers

July 31, 2017

The Great American Eclipse Archive

The ALPO Solar Section has setup a folder in its archive for images made during the Great American Eclipse on August 21, 2017. The folder is a sub-folder in Carrington Rotation 2194 and can also be found at the following URL:
http://www.alpo-astronomy.org/gallery/main.php?g2_itemId=104414 .
Any observer who has made an image of the event, be it the total eclipse, or partial, can submit the image(s) to ALPO by emailing it to:
solarimages@alpo-astronomy.org . We are asking that the images are identified with the observer’s name, the exact time in Universal Time, and location, from where the image was taken. Staff will upload the images into the archive where they are available for analysis. Please note that the size of the images is limited to <2500 pixels wide and we prefer images in the 200k – 300kB file size. However, larger images are also accepted. We hope that many will make use of this option to document the Great American Eclipse of 2017!
The Solar Section Team.

July 17, 2017

A short Summary of Carrington Rotation 2191

Carrington Rotation 2191 covered the time period from 2017-05-26 2030 UT – 2017-06-23 0117 UT.
The rotation showed a decrease in Active Regions compared to previous rotations, and so did the number of submissions. 298 Submissions were added to the archive at the time of this summary, and can be viewed in ALPO’s Solar Archive for CR2191:

The rotation started 2017-05-26 with 1 Active Region and a Wolf number of 22. The total Active Region Area was 170 millionths. During the rotation we could observe 5 regions, AR2659 – AR2664. Please note that AR2660 was a short lived region during the previous rotation. The highest Wolf Number of 35 was reached on the last day of the rotation on 2017-06-23, while AR2659 was the largest Active Region of the rotation at the 3rd day of the rotation on 5/29 with 220 millionths. The rotation had a period of 4 spotless days from 6/10 till 6/13 as well as a single day on 5/31, bringing the total spotless days since Solar Maximum to 77. The rotation ended with three Active Regions, AR2662, 63 and 64, having a Total Active Region Area of 120 millionths and a Wolf Number of 35.

For this Rotation we would like to feature three images by three of our observers, Jon O’Neil, Randy Tatum, and Dave Tyler. Thanks to them, as well as all other contributors, for another great rotation. Please take a look at their images by clicking on the link above, leading to our archive for CR2191.
Clear Skies,
Theo Ramakers
Acting Assistant Coordinator, the ALPOSS

June 05, 2017

A short Summary of Carrington Rotation 2190

Carrington Rotation 2190 covered the time period from 2017-04-29 1509 UT – 2017-05-26 2030 UT.
Solar Activity decreased during the rotation, and so did the number of submissions. 325 Submissions were added to the archive at the time of this summary, and can be viewed in ALPO’s Solar Archive for CR2190:

During the rotation we could observe 9 regions. The rotation started on 2017-04-29 with 3 Active Regions, a Wolf number of 35, and a total Active Region Area of 100 millionths which was the highest Total Active Region Area for the rotation. The highest Wolf Number of 55 was reached towards the end of the rotation on 2017-05-23. The rotation had a period of 7 spotless days from 5/10 till 5/16, bringing the total spotless days since Solar Maximum to 72. Two areas contended for the largest daily area of 80 millionths, AR2664 on May 5th and AR2659 on 5/26. The rotation ended with one Active Region, AR2659, having a Total Active Region Area of 80 millionths and a Wolf Number of 19. Besides the number of Spotless days, the low Active Region Areas, and the low number of spots compared to the previous rotation, CR2190 included three very short lived regions lasting only 1 (AR2657), 2 (AR2660), and 4 (AR2655) days only.

For this Rotation we would like to feature three images by three of our observers, Guilherme Grassmann, Christian Viladrich and Howard Eskildson. Thanks to them, as well as all other contributors, for another great rotation. Please take a look at their images by clicking on the link above, leading to our archive for CR2190.
Clear Skies,
Theo Ramakers
Acting Assistant Coordinator, the ALPOSS

May 18, 2017

A short Summary of Carrington Rotation 2189

Carrington Rotation 2189 covered the time period from 2017-04-02 0848 UT – 2017-04-29 1509 UT.
The increased solar activity created an increase in the number of submitted reports and images which totaled 517 at the time of this summary, and can be viewed in ALPO’s Solar Archive for CR2189:

During the rotation we could observe 9 regions. The rotation started on 2017-04-02 with 4 Active Regions and a total Active Region Area of 740 millionths, and Wolf number of 79. That day the Sun produced several flares, including 2 flares which were the cause of R2 alerts. (>M5.0 flare) The 2 flares were registered as M5.3 and an M5.7, and both originated in AR2644. AR2145 continued to grow to its maximum of 700 millionths which it reached 2 days later on 2017-04-04, which coincided with the maximum Total Active Region Area of the rotation at 1270 millionths, and a max. Wolf Number for the Sun of 97. The Total Active Region Area for the rotation was interrupted briefly twice for a total of 3 spotless days, bringing the total spotless days since Solar maximum to 65. The rotation ended with a Total Active Region Area of 110 millionths and a Wolf Number of 23.

For this Rotation we would like to feature three images by three of our observers, Guilherme Grassmann, who caught the end of an M2.3 flare in AR2644 on April 2nd, Theo Ramakers, showing a WL image of AR2645 when it was at its maximum size of 700 millionths on April 4th, as well as a very nice image of a prominence by Raffaello Braga from Italy on April 3rd. Thanks to them, as well as all other contributors, for another great rotation. Please take a look at their images by clicking on the link above, leading to our archive for CR2189.
Clear Skies,
Theo Ramakers
Acting Assistant Coordinator, the ALPOSS

April 12, 2017

A short Summary of Carrington Rotation 2188

Carrington Rotation 2188 covered the time period from 2017-03-06 0126 UT – 2017-04-02 0848 UT.
328 Reports and images were submitted and can be viewed in ALPO’s Solar Archive for CR2188:

During the rotation we could observe 6 regions, half of which were only visible for about three days or less and two of them did not make it above 10 millionths. The rotation did start with a re-emergence of AR2141 for one day, with a size of 10 millionths, followed with a spotless streak of 15 days. The largest region, AR2645, reached its maximum area of 380 millionths on the last full day of the rotation on April 1st. This day also marks the maximum for the rotation of the Total Daily Active Region Area which was at 580 millionths while the Wolf Number maxed out at 79. The rotation did have a total of 16 spotless days, bringing the total spotless days since Solar maximum to 62.

For this Rotation we would like to feature three images by three of our observers, James Kevin Ty, David Teske, and Howard Eskildsen. Thanks to them, as well as all other contributors, for another great rotation. Please take a look at their images by clicking on the above link leading to our archive.
Theo Ramakers
Acting Assistant Coordinator, the ALPOSS