This view provides a comparison between a visible image (left) of the reflection nebula IC 1396 – an intense star forming region - and a mid-infrared view of the same area as seen by AKARI’s satellite (right).
In the visible light (left image) it is possible to see the emission from ionized (charged) hydrogen gas as well as light emitted from the massive stars in the centre and scattered by the interstellar dust. High density gas clumps are seen as dark stains. New stars born in these dark regions do however appear bright if observed in infrared light (right image).
Massive young stars, recently born in the centre of the imaged area (right image), blow out interstellar gas and dust and create the giant hollow seen in the central region. The gas that has been swept out creates the bright filament-like structures seen in the infrared in the surrounding regions. The dust in the gas is heated by the intense light coming from both the massive star at the centre of the nebula and the newly born stars in the dense gas itself, and emits infrared light. The bright clump seen on the slightly off-centre right-hand side is known as the ‘Elephant Trunk Nebula’, a star forming region too. It appears as a dark nebula in the visible light (left image), but it is very bright in the infrared. It is a clump of dense gas that was not originally blown away because of its very high density.