20. March 2015: Partial Solar Eclipse from Munich
Giancarlo Lombardi, Manfred Rudolf, Giancarlo Tomezzoli
The Eclipse Observation Session organised on 20/03/2015 by the EurAstro
Association, the ASTRO Club and the Marco Polo Club here in Munich, was
well attended and successful thanks to the favourable weather.
We were surprised by the large and enthusiastic interest the eclipse
generated among the public.
Various instruments, from small telephoto lenses to big telescopes, were brought
by the observers for observation and photographing the eclipse.
The eclipse begins..
The sun was very quiet on eclipse day and only a tiny sunspot could be seen (at lower left).
Note that the center of the Sunīs disc appears brighter than the Sun's edge or limb ("limb darkening").
This effect is due to the increased absorption of the Sunīs atmosphere in the line of sight to the limb.
For more info on limb darkening see here.
People watched the progress of the eclipse, with protective glasses, their mobile phone cams or through the telescopes...
The eclipse reached its maximum in the late morning, with a coverage of 68%, and ended just in time for lunch...
Some colleagues used their mobile phone cameras to get pictures of the eclipsed Sun from larger instruments
Some instruments allowed observation of the Sun in the monochromatic light emitted by hydrogen. A H-alpha filter
blocks all wavelengths of the visible light except the red light emitted by hydrogen (656.3 nm). Such filter arrangement
allows one to see the upper atmosphere (chromosphere) of the Sun, including prominences on the solar limb which would otherwise
be too faint to be seen because of the extreme brightness of the Sun's disc in the other wavelengths.
More info about H-alpha filters and observations can be found here.
Note the tiny yellow dot on the left side of the image above: this dot is, to scale, of the size of the Earth. The Sun, although a dwarf star,
has a diameter of 109 times that of the Earth. One sees that even the small prominences visible on eclipse day surpass the size of the Earth.
Note also that the tiny sunspot visible in the solar images above, is about the size of the Earth...