Disk Animations

Three freeware Windows® programs are available for the calculation of sunspot locations and their area plus much more: Helio v4.1, Helio Viewer v2.1 and Helio Creator v2

Helio

The freeware Helio v4.1 program includes the following features:

  • Determine the solar position (RA, Dec, altitude and azimuth) and solar parameters (Bo, Lo, P, apparent diameter and Carrington rotation of the central meridian) for a given date and time, and observer latitude and longitude.
  • Select the orientation of the solar disk (including equatorial and altazimuth).
  • Display the central meridian, solar equator, latitude lines and longitude lines.
  • Input or select the position of a sunspot directly on the solar disk.
  • Calculate the sunspot latitude and longitude.
  • Input the sunspot size and calculate the sunspot area (in millionths of a solar hemisphere).
  • Display the Carrington Rotation number at the location of the sunspot.
  • Track a sunspot across the disk and from one rotation to the next (or previous) using either Carrington or differential rotation rates.
  • Produce a log file for sunspot measurements.
  • User guide (PDF format).

Helio v4.1 can be download as a zip file. The user guide is included in the zip files or it can be downloaded here. If you have any problems with this program, please email me.

Helio Viewer

As a solar observer who makes full disk drawings and who wished to determine the latitude/longitude and area of spots groups, I wanted an easy way of measuring these parameters without the need for lots of hand calculations. Developed from Helio v2.0 (see above), Helio Viewer drastically reduces the time required to analyse my solar observations. There are two basic modes of operation of Helio Viewer: with the artificial Sun (as appears above) or a user full disk solar image (such as those on this web site). Helio Viewer has the following features:

  • Input of a user full disk image, such as those on this web site or those with the solar disk surrounded by a black background, in bitmap format.
  • Determine the solar position (RA, Dec, altitude and azimuth) and solar parameters (Bo, Lo, P, apparent diameter and Carrington rotation of the central meridian) for a given date and time, and observer latitude and longitude.
  • Select the diameter of the artificial Sun or display the user solar image at its full size.
  • Select the orientation of the solar disk (including equatorial and altazimuth).
  • Display the central meridian, solar equator, latitude lines and longitude lines.
  • Input or select the position of a sunspot by clicking directly on the solar disk.
  • Calculate the sunspot latitude and longitude.
  • Calculate the sunspot area (in millionths of a solar hemisphere).
  • Display the Carrington Rotation number at the location of the sunspot.
  • Track a sunspot across the disk and from one rotation to the next (or previous) using either Carrington or differential rotation rates (artificial Sun only).
  • Superimpose the Solar Environment Center (SEC) Solar Region Summary (SRS) report to show the location, region number, group type and area.
  • Measure the separation between two points on the solar disk or outside the solar disk.
  • Produce a log file for sunspot measurements.
  • User guide (PDF format).

Further information and screenshots for this program can be found here (based on v1). Helio Viewer can be download as a zip file. The user guide is included in the zip files or it can be downloaded here. If you have any problems with this program, please email me. The previous version is still available as a zip file.

Helio Image Creator

As I create electronic copies of disk drawings for display on this web site, I wanted an easy way of centering the images, adding annotation such as date & time, cropping to a given size and adding a border. Helio Image Creator performs these functions.

Thus Helio Image Creator has the following features:

  • Inputs a user full disk solar image (in bitmap format).
  • Determines the center of the solar image.
  • Changes the orientation of the image via a flip/mirror or rotation by any angle.
  • Creates a solar image of a specified size, adds annotation to top left, top right, bottom left and/or bottom right of the image and/or adds border.
  • Outputs the created image in bitmap format.
  • Creates and outputs a mask (red pixels) for either the whole disk or individual sunspot groups.

Helio Image Creator can be download as a zip file. The user guide is included in the zip files or it can be downloaded here. If you have any problems with this program, please email me.

Last updated on 16 May 2021.