The Report of Spectroscopy Group

by Kambiz Janamian

It was for the first time in Iran that an amateur group decided to do the spectroscopy of the Sun and the corona. We did not have any equipment ready for this job; and we had to make everything. The group on spectroscopy, too, had started its work one month before the eclipse.

The group had to do tree main jobs: First, they had to make an equipment being able to always focus the Sun's light on a specific place ( Heliostat ). Second, they had to make an equipment determining the spectrum of the light of the Sun and corona. Third, they had to select the tool for registering these spectra.

To do the first job they made the Heliostat, getting help from and industrial company. In this tool, the light of the Sun was reflected on a convex mirror by means of a flat mirror; and it could be fixed on a specific point by means of the convex mirror. The flat mirror was joined to an engine and it could follow the movement of the Sun. After having the permanent light of the Sun, now it was the time for us to make a spectroscope. The group used two 45-degree prisms and a achromatic lens. In order to make the gap for penetration of the light, after testing the shaving razors and pencil sharpener razors, the group decided to make a mechanical gap. All the parts were installed in a small box. The box was put on a desk in the way that the light coming from the Heliostat was focused on the gap where the light entered.

In order to register the spectrum, the members of the group made use of two instruments: a film making camera and a photography camera. For magnifying the spectrum lines more, they put a 4.5" Newtonian telescope behind the spectroscope and did their photography of the spectrum with the eyepiece of the telescope. The watched the solar spectrum and different lights before the eclipse and took some photos. Their report the August 11th eclipse is as follows:

Final Experiment

The final experiment was carried out in Chadegan. After the experiment, photography and developing the films we came to the conclusion that, the 4.5" telescopes were not suitable for the job due to some reasons and the ASA 400 film is more suitable. After installing the system, we could get the solar spectrum well and the Fraunhofer lines were almost visible. But during the total eclipse we could not get spectrum of the corona due the shortage of light, which we could compensate in some way which again required some experience we did not have for it was our first time observing the eclipse and could not prepare the spectroscope earlier for the experiment.

Of course, the reason why we really could not get the corona's spectrum by means of our prismatic spectroscope requires more study, which we will do in the future. But our main problem was the presence of little light in the corona to the extent we had not predicted. Of course, we had been able to get the spectrum of the very faint lamps before; and although we had the light of the solar spectrum up to the last minutes of the partial eclipse, the light totally faded in the time of total eclipse.

We hope to find the problem on the corona's spectrum by more research, and revise the system if it has some problems ( if we can do this with the available facilities ). No doubt, this spectroscope is suitable for most of the related works such as getting the solar spectrum since we could get a very good solar spectrum.
Notwithstanding, according to the designers of the instrument, the project was 95% successful, especially, when the spectroscopy of space matters ( such as the Sun ) was being done for the first time.

the members:

Kambiz Janamian

Kian Kiani