Author Archives: Roger Samworth

Spot 2706 and “Chromosphere Sequence” 22/04/2018

Here is this morning’s image of spot 2706, together with the “chromosphere sequence” for the spot as suggested in my post the other day. (

Here is a movie as you travel down through the chromosphere:

Layers in the Solar Chromosphere

Here is an interesting thought inspired by Pete Hill’s “solar array”.

If we observe the Sun in white light, we are seeing the photosphere.

If we observe the Sun in H-alpha light, we are seeing the chromosphere.

The chromosphere (literally, “sphere of color”) is the second of the three main layers in the Sun’s atmosphere and is roughly 3,000 to 5,000 kilometers deep.

If we therefore mix a white light with a Ha image in different proportions, are we seeing different layers as we go through the chromosphere?

By a fortuitous coincidence my Ha scope and the scope I use for white light imaging have the same focal length, and so produce the same sized images. So this mixing is quite easy to do.

Here is sunspot 2699 on 07/02/2018 together with the mixed sequence.