NGC 6357

Imaged by Jean-Yves Beninger from Singapore on 14 July 2005

H-Alpha filter imaging

SKY90 - SBIG ST8 - AP600EQMD mount

Stack of 28 images, 3 minutes each

H-Alpha Bin 1x1 : 84mn


NGC 6357 is a large emission nebula in Scorpius.

When an electron from an hydrogen atom falls from a higher to a lower energy level, the energy difference is emitted as a photon.

This image is taken through a filter that selects the Hydrogen Alpha photon, the smallest fall in the Balmer series ( from level 3 to level 2 of the different levels allowed for an electrron).