It has been just over one year since I posted my last solar blog. As an individual who enjoys observing and imaging our Sun, going through the period known as solar minimum was not enjoyable. The Sun was virtually void of sunspots, prominences, filaments, and plages for a very long time. To review, a solar cycle is approximately an 11-year period that is measured by the number of sunspots visible on its surface. During this time the Sun becomes evermore magnetically active creating all kinds of very interesting visible features when observed using various type of solar filters. At its peak the cycle is known as solar maximum. During the cycle there is a reverse in the magnetic fields and the activity diminishes to what is known as solar minimum. And the cycles repeat themselves at varying levels of activity.
The chart below (courtesy of Hathaway NASA/ARC) shows that Solar Cycle 24 was relatively calm as compared to the two cycles preceding it.
Spaceweather.com (www.spaceweather.com) keeps a running total number of days that are "spotless".
Spotless Days
Current Stretch: 0 days (as of 3/27/2021)
2021 total: 32 days (37%)
2020 total: 208 days (57%)
2019 total: 281 days (77%)
2018 total: 221 days (61%)
2017 total: 104 days (28%)
2016 total: 32 days (9%)
2015 total: 0 days (0%)
December 2019 marked the official beginning of Solar Cycle 25. As an observer, you really could not tell that much had changed from solar minimum at the end of Solar Cycle 24. But as 2020 marched on, there were moments of excitement where sunspot groups as well as other features appeared.
November 8, 2020
November 26, 2020
Keep in mind, although sunspots may be visible on any given, my observing and imaging is often blocked by clouds and pay-job working hours. Relative to these conditions, combined with some incredibly cold weather, there was not much solar observing going on in my life for the early part of 2021. Along comes March with some milder weather and clear skies on the weekend, and solar observing on my deck in the backyard is resumed. Although sunspot activity has been minimal, there have been other activities such as prominences, filaments and plages. One thing I really like to look at is the magnetic activity around a sunspot and a plage. It is clearly visible when observing in Hydrogen-alpha (Hα - 656.28nm) as was done in all of these pictures. You can see this by observing of the shapes the plasma takes on around those features. It is much like the experiments we did in school with a magnet and metal filings.
March 7, 2021
March 13, 2021
March 20, 2021
March 21, 2021
March 27, 2021
Will Solar Cycle 25 be another mild activity cycle. That had been the prediction and discussion for much of the end of Solar Cycle 24. However, EarthSky (https://earthsky.org/space/sunspot-cycle-25-among-strongest-on-record-says-ncar) ran a story on December 26, 2020 suggesting that Solar Cycle 25 "could be among the strongest on record". Not so good for those responsible for keeping our communications systems, power grids, and satellites safe and working properly. However, for a solar observer and imager, it would be liking striking solar gold.
Until next time.... Clear Skies!
Phil Whitebloom is currently the President of Howard Astronomical League (HAL) and continues in his role as Solar Observing chairperson.
www.howardastro.org
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