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The Solar Observatory

Undergraduate student Joe Calleja-Gera tunes the H-alpha filter while taking solar observations.

Cardiff undergraduate student Joe Calleja-Gera tunes the H-alpha filter while taking solar observations.

An H-alpha filter is now being used in conjunction with the Meade telescope for solar astronomy.

With this filter we can take images of the Sun to examine details such as sunspots, solar flares and prominences. In this way we can study the energetics of the Sun.

Below: Two different views of the Meade 12-inch telescope with the H-alpha filter mounted:

Side view of the Meade 12-inch telescope with the H-alpha filter mounted.
Close-up of the Meade 12-inch telescope with the H-alpha filter mounted.


Below: These two pictures show Cardiff undergraduate students Alex Nichols and Danielle Moakes with the 12-inch Meade telescope. Alex on the left is mounting the H-alpha filter on the telescope, while Danielle on the right is adjusting the eye-piece and infra-red filter:

Cardiff undergraduate student Alex Nichols with the 12-inch Meade telescope, mounting the H-alpha filter on the telescope
Danielle Moakes with the 12-inch Meade telescope, adjusting the eye-piece and infra-red filter


a very clear solar prominence visible on the limb of the Sun.

Right: The image on the right was taken by Danielle and Alex through the H-alpha filter on the afternoon of 2002 October 10th. It shows a very clear solar prominence visible on the limb of the Sun. There is a vertical column at one end of the prominence and a huge arch connecting the top of the column to the sun's surface. The scale of this image is such that the Earth would fit underneath the arch!



Very clear solar prominence visible on the limb of the sun.

Left: The image on the left was taken by Danielle and Alex through the H-alpha filter on the afternoon of 2002 October 23rd. It shows another very clear solar prominence visible on the limb of the Sun.


An MPEG movie of the above prominence [3.11 MB]

a solar flare visible on the limb of the Sun.

Right: This image was taken by Danielle and Alex through the H-alpha filter on the afternoon of 2002 October 23rd. It shows a solar flare visible on the limb of the Sun.

H-alpha is a fundamental spectral emission line of the Hydrogen atom. It is part of the Balmer series of the Hydrogen spectrum. It is emitted when an electron in a Hydrogen atom goes from the n=3 to n=2 state. The wavelength of this transmission is 656.5nm. By using a narrow filter we block most of the Sun's radiation and see these details.

WARNING: DO NOT LOOK AT THE SUN DIRECTLY OR THROUGH A TELESCOPE WITHOUT SOLAR FILTERS.

IT IS NOT SAFE TO LOOK AT THE SUN EVEN THROUGH SUNGLASSES. SERIOUS EYE DAMAGE CAN RESULT.