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Orion in H-alpha

H-alpha reverse
conventional view
with labels

Date:16.11.2001 Time:0:22 UT Exposure:6 x 10min
Field of View:17o x 30o Receiver: DWARF, 20482 CCD Filter:H-alpha
Instrument: f=100mm, 1/2.8 Observatory: Hoher List Observer:Till Credner

© Copyright by the observers

The image shows the entire field of the constellation Orion in the light of ionized hydrogen at 656 nm. The field is filled with glowing hydrogen gas: in the north the spherical nebula Sh 2-264 around the star lambda Orionis, in the lower left the huge arc called Barnards Loop, in the lower center at the three belt stars the well known IC 434 (including the prominent horsehead dark nebulae), and below Orions sword region with the great Orion nebula M 42/43.

This region is home of the giant Orion molecular cloud in which strong star formation takes place. Young and hot stars make up the Orion OB1 association at Orions belt and sword region but also around lambda Orionis. The intense ultraviolet radiation of these stars ionizes the surrounding hydrogen and therefore makes it glow at the so called H-alpha wavelength of 656 nm (at recombination).

  • the Orion Cloud page at SEDS