The activity of the sun is constantly changing. In the region of ionized hydrogen (in the H-alpha spectral line) it shows an active surface and prominences.

Sun on May 9, 2024

The gigantic sunspot AR3664/AR3668 is the origin of the largest geomagnetic storm of the last 19 years! From there several Flares reached earth.

Telescop: Coronado SolarMax III 70mm

Camera: ZWO ASI2600MM Pro                                      & ZWO ASI174MM


True-Etalon-Filter 60 mm <0.7 Ångström, BF15 Blockfilter


The difference between H-Alpha and white light solar photography

Observing the sun through a telescope is only safe with special filters!

The term H-Alpha solar photography refers to photographing the sun with an H-Alpha filter (fig. A). The line of ionized hydrogen corresponds to a certain bandwidth of the electromagnetic spectrum and is 656 nm (nanometers).This is how the surface structure of the sun (chromosphere) and protuberances become visible.

Observing the Sun in white lightmeans observing the part of the spectrum that is visible to the eyes - from short-wave blue light to long-wave red light (fig. B) . The mixture of these colors produces white light.

Date:  (A.) April 30. 2023 in H-Alpha , (B.) May 09. 2021 in white light

SUN DISK in H-Alpha

Partial Solar Eclipse on June 10, 2021


Solar eclipses occur when the sun, moon and earth are exactly in line. The moon moves in front of the sun and casts a shadow on the earth. So they can only occur at new moon, when the moon moves between the earth and the sun. However, a solar eclipse does not occur on every new moon phase. During the 1919 solar eclipse, Albert Einstein's theory of relativity was proven for the first time. Einstein predicted that a large mass deflects light.   In fact, during the eclipse, researchers saw light from  stars adjacent to the sun that were actually behind it.