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Sunspots, 25 June - 23 August 1975

During 1974 there was considerable interest among members of OASI in observing the Sun. Responding to the interest, John Deans, Newsletter editor, encouraged members to make observations daily. The following year, on 01 June 1975, the committee launched a project aiming to record the progress of sunspots on a day-by-day basis by means of sketches of the solar disk produced on a standard 60 mm diameter template. It was intended to display the drawings at the open day on 04 October 1975. The project was supported by an article in the Newsletter describing techniques for solar observation.

Unfortunately, fewer observations were submitted than was hoped! Nevertheless, the best observations, by Roy Cheesman and John Deans, are reproduced below. Key parameters of the observations are as follows:
 


Date


Time

Observer


Telescope


Mag.

Rotation Number


P


B0


L0

25 June
19:05
R M Cheesman
Orwell Park refractor
132x
1629
-5.4°
2.2°
126.4°
02 July
18:45
R M Cheesman
Orwell Park refractor
144x
1629
-2.1°
3.0°
40.9°
09 August
15:00
J D Deans
80 mm refractor
54x
1631
13.9°
6.4°
256.5°
13 August
18:45
J D Deans
80 mm refractor
54x
1631
15.3°
6.6°
205.6°
16 August
15:30
J D Deans
80 mm refractor
54x
1631
16.3°
6.7°
164.2°
23 August
12:00
J D Deans
80 mm refractor
54x
1631
18.6°
7.0°
69.8°

19750625_sunspots_RMC.gif 25 June.

19750702_sunspots_RMC.gif 02 July.

19750809_sunspots_JDD.gif 09 August.

19750813_sunspots_JDD.gif 13 August.

19750816_sunspots_JDD.gif 16 August.

19750823_sunspots_JDD.gif 23 August.