February 20, 2013
The NASA SDO mission released a fascinating video showing "rain" from a magnetic loop falling back onto the surface of the Sun. It's not rain, but hot plasma magnetically levitated off the Sun!
February 15, 2013
Observer k-coefficients have been recalculated or newly-calculated for 60 observers, including 24 active observers who did not previously have them. The January 2013 Solar Bulletin is the first set of Ra' values with these newly-computed ks.
March 9, 2012
The large sunspot group 1429 unleashed another large (M6) flare today, in addition to the very large (X5) flare early in the morning (UT) of March 7, 2012. A geomagnetic storm from the March 7 eruption is currently underway, and many spectacular aurorae have been reported. A CME has also been reported for today's flare, and is expected to make a direct hit on the Earth on March 11. Be on the lookout for more bright aurorae!
December 15, 2011
A paper by L. Lefèvre and F. Clette of the Royal Observatory of Belgium comparing several different sunspot indices during Cycle 23 was published in Astronomy & Astrophysics
October 24, 2011
The Earth was hit by a large Coronal Mass Ejection from the Sun around 18:00 UT, and bright aurorae were visible as far south as the southern continental United States!
October 10, 2011
September 15, 2011
The scanned archives of the Solar Bulletin now extend back to Volume 31, 1975. The NASA ADS Abstract Service now lists the AAVSO Solar Bulletin among its publications! Search for the journal code "AAVSB".
September 14, 2011
September 7, 2011
Multiple SID observers noted the sudden ionospheric disturbance caused by the X2 solar flare on September 6. The NOAA Space Weather Prediction Center predicts a chance for a minor geomagnetic storm beginning around 2011 September 9.
August 5, 2011
Thanks to Roberto Battaiola, we now have back issues of the AAVSO Solar Bulletin from 1989 to the present online! Many thanks to Roberto for providing us with scans of back issues from 1989 through 2001.
August 4, 2011
We have established a new general purpose mailing list for solar observers: aavso-solar ! You can subscribe by clicking that link and the "subscribe" link that's found next to the entry for the Solar Section. And don't forget that we have a list for SID observers as well: aavso-sid-list !
Volunteer Roberto Battaiola of Milan, Italy has provided the first scans of Solar Bulletin back issues! Volume 45, numbers 6-12 (June-December 1989) were added to the Solar Bulletin archive today.
July 21, 2011
Volunteers wanted! If you live within easy commuting distance of AAVSO Headquarters and would like to help us digitize back issues of the Solar Bulletin , please contact Dr. Matthew Templeton at AAVSO Headquarters.
June 7, 2011
March 24, 2011
This beautiful video of time-lapse photography of aurorae taken from Northern Norway has been making the rounds on the internet, and although it's not directly about the Sun itself, it's definitely worth watching!
Bolivian solar observer Gonzalo Vargas sent us another sketch of solar activity from March 21, this time of a loop prominence (possibly associated with group 1165):
February 15, 2011
The Sun is very active right now, and sunspot group 1158 has unleashed a number of C and M class flares, with one X2 flare on February 15! AAVSO SID observers reporting clear SIDs over the past few days. More info from NASA here .
January 28, 2011
Gonzalo Vargas of Cochabamba, Bolivia reports a large solar prominence & filament off the southeastern limb of the Sun, and included a pencil sketch with the report:
January 13, 2011
Lionel Loudet provides an analysis of VLF SID observations during the 2011 January 4 partial solar eclipse.
The Sky & Telescope cover story for February 2011 is a discussion of the impacts of solar storms on terrestrial power systems. This issue also includes an article on the Solar Dynamics Observatory. You can find S&T's page of links about SDO here .
Items of interest
Last Updated: February 21, 2013 - 3:02pm