Abstract: 1. Observing and drawing of sunspots using a telescope and a paper screen. Gauging of the Wolf numbers. Estimating the areas of the sunspots. Determining the heliographic coordinates of the sunspots. Calculating the rotational period of the Sun for certain heliographic latitudes. 2. Estimating the velocity of the matter in a prominence on the limb of the Sun. Needed are few CCD images of such a prominence for different moments of time, obtained in some of the professional observatories in Astronomy On-Line. 3. Estimating the velocity of the particles of the solar wind. Needed are data from the scientific centres taking part in Astronomy On-Line about the moments of time when a chromospheric eruption on the Sun occurred and when a magnetic storm on the Earth was caused.

Full Text of Proposal

Comments by OPC

General Comments: The proposed exercises are interesting, but unfortunately parts 2 and 3 require professional equipment dedicated to solar observations, which is not available for Astronomy On-Line. As to part 1, the equipment available in the participating observatories is not suitable for observing the Sun; the authors are however encouraged to carry it out with a small telescope and extend the observations over a period longer than that covered by the "hot week" of Astronomy On-Line.

Visibility: No problem for the Sun!

Special Comments: The authors may also consider carrying out some of the proposed exercises using already published material, in addition to measurements obtained from their own observations. Unfortunately, the solar cycle is near minimum at present.

Expected time consumption (including overhead):Devoting only 10 or 15 minutes every day over a period of a few months would allow measurements of the rotation of the Sun and statistics of sunspots (unfortunately, the solar cycle is near minimum at present).

Proposed facility: Almost any small telescope could be used for point 1 of the proposal.