Disk Animations

The major changes to the site (excluding disk drawing and regular updates) are listed below.

  • 28th September 2020 - New versions of the Helio programs now available. Updates information about measuring sunspot areas.
  • 24th April 2020 - Created a Solar Papers page.
  • 21st December 2014 - The Solar Observing DVD is no longer available.
  • 1st June 2013 - Added PDF document describing how to construct a project box to the Observing the Sun webpage.
  • 28th February 2013 - Animations are back! This time for whole years.
  • 4th June 2010 - Solar Observing CD-ROM replaced with a data DVD.
  • 25th April 2006 - Included new page on the parallactic angle (for observing with altazimuth mounts).
  • 8th March 2006 - Included new pages for eclipses of the Sun.
  • 17th February 2006 - Included new page for hydrogen alpha disk drawings.
  • 5th February 2006 - Helio Viewer and Helio Creator programs now freeware and price of Solar Observing CD-ROM reduced.
  • 19th January 2006 - included larger version of the 'Sun from Earth' animation and a zip version of the Helio v3.2 software.
  • 23rd November 2005 - Web site transfered to http://www.petermeadows.com with all drawings and animations.
  • 10th September 2005 - The freeware Helio program upgraded to v3.2 (the orientation of the solar disk can be selected for altazimuth telescope mounting).
  • 16th January 2005 - Disk animations from 2001 are only available on CD-ROM.
  • 16th October 2004 - The freeware Helio program upgraded to v3.1 (the user can change the number of digits displayed for various parameters, the number of digits output to the logfile has been increased and a message can be displayed when using the logfile).
  • 30th June 2004 - The freeware Helio program upgraded to v3.0.
  • 20th June 2004 - Disk drawings from 2000 (159 drawings) and disk animations from 2000 are only available on the CD-ROM.
  • 10th June 2004 - Added transit of Venus observations.
  • 22nd February 2004 - Disk drawings from 1997 (1 drawing), 1998 (45 drawings) and 1999 (177 drawings) are only available on the CD-ROM.
  • 22nd February 2004 - Disk animations for 1999 are only available on the CD-ROM.
  • 1st September 2003 - Introduced the HelioViewer and HelioCreator software programs and CD-ROM.
  • 13th May 2003 - Added pages on Solar Books and Transits.
  • 15th January 2002 - Further information on the McIntosh sunspot group classification given in the Glossary.
  • 17th November 2001 - Included new pages showing the development of sunspots for some groups during 2000 and 2001.
  • 25th February 2001 - All disk animations for 2000 have been generated using jpg disk drawings.
  • 11th February 2001 - All disk drawings for 2000 are in jpg format.
  • 19th August 2000 - The Sunspot Area page now includes charts to derive the angular distance of a sunspot from the disk centre to enable sunspot area to be calculated via an equation.
  • 15th July 2000 - Helio v2.0 has been issued - this version includes a display for solar right ascension/declination, solar altitude/azimuth and calculates sunspot areas. See the Software page to download this program.
  • 15th July 2000 - Helio v1.2 has been issued. See the Software page to download this program.
  • 27th April 2000 - The Helio program has been modified to enable the date and time box sizes to be changed to accommodate different windows date and time formats. The date can now be shown in either the short or long formats.
  • 25th April 2000 - A new page - Sunspot Trends - has been added to show the long term trends in the Sunspot Number and Sunspot Area using smoothed data.
  • 20th April 2000 - A new page - Sunspot Numbers - has been added to show the the sunspot number R derived from individual drawings.
  • 6th March 2000 - A new plot has been added to the Sunspot Measurements page to shows the northern and southern hemisphere sunspot group numbers: one hemisphere can dominate activity for several months before switching to the other hemisphere.
  • 14th January 2000 - Self extracting zip file included for Helio v1.0 software.
  • 8th January 2000 - Launch of re-formated web site.

Last updated on 28 September 2020.