Sol – Our Sun

To understand more about the stars, we have Sun right next to us in the solar system to learn and study more and have better in depth knowledge about the life cycle of other stars. Sun is bright and hot object in the sky. Even at 150 million kms it is still very bright and hence we need to follow certain precautions in order to avoid any damage to us or the instruments while observing.

Direct Observations

The sun is too bright to look directly at it. The observation will lead to permanent complete damage to the human eye or irreparable damages to the equipment used for direct observations. So what are the ways in which we can look at the Sun but still protect ourself?

• • Use of Solar filters: There are special filters which can be used to block about 99.9% of the light coming from Sun. The filter can be made using specialise thin aluminium sheet which gives a white image of the Sun or using a black polymer natural density filters which gives orange/yellow images of Sun. The filters not only block the visible light from the Sun but also filter out most of the wavelength of light and hence help us in observing Sun in specific light colours. These filters can be placed in front of the telescope or binoculars or lens of the camera if looking for astrophotography. These filters are available for your telescope/binocular and you can order the same online. It is of utmost importance to purchase the filters from reliable astronomy store near you or else it may risk your eyes. The filters shall be preserved very carefully as even a microscopic scratch can allow enough amount of light to pass through which can cause damage to your eyes. So please be careful and use the filters very carefully.
  • Use of Pinhole Projectors: The pinhole projector is a simple tool we have made in our arts and craft workshops in school where we made small pinhole devices and tend to look at the surroundings. This time we will make one to observe the Sun. The direct method can help you observe the Sun during any solar event (like eclipses, transits of inner planets or big sunspots).

Indirect Observations

If you can not get a solar filter for yourself don’t loose hope as there a many indirect ways to locate, observe and study the Sun.

• • Using Telescope Projection Method: The telescope is a good tool for magnifying images of the object. Also the lens arrangement help you achieve a sharp and focused images which can be projected on a piece of white paper placed normal to the eyepiece. The image so projected will be sharp, and big enough to make substantial observation. This method can enable mass observation as more people can see the image in one go rather than one person spending minutes looking at the sun through the telescope and filter. This also ensures that you are avoiding the risk of damaging your eyes in all possibilities.
  • Using Binocular Projection Box: Indeed a very good tool especially for the students and individuals interested in measuring the diameter of Sun and do other mathematical calculations, this method is very practical and leads to many new findings. The students create a wooden/card box and place binoculars on top and put a graph paper at the bottom inside the box. One can follow the Sun as it moves in the sky while marking the position of Moon during an eclipse, Mercury/Venus during transit or simply tracking a sunspot in order to observe them from long periods and also track their path/measure surface area/velocity of rotation etc.
  • Using Ball Projector: The ball protector is a simple device we can make at home using a concave mirror and a convex lens placed at the right distance to obtain a sharp image of Sun on a wall or board for general large gathering. The next topics can be useful for your school projects as well.