The
famous HorseHead Nebula in Orion (also known as Barnard 33) as seen from Calar Alto. Its unusual
shaped nebula was first spotted in 1888 on a photographic plate taken
at the Harvard College Observatory. The nebula is located just below
Alnitak, the easternmost star of Orion's Belt, lies at a distance of
about 1500 light-years from Earth, and is approximately 3.5 light-years
wide. The red glow originates from hydrogen gas predominantly behind
the nebula, ionized by the nearby bright star Sigma Orionis. The
darkness of the Horsehead is caused by tiny, sub-micron sized particles
of interstellar dust (smaller than 40 millionths of an inch).
This image is a RGB composition produced by the combination of the four
images obtained simultaneosly with an exposure of 300 seconds by Oliver
Cordes with the Simultaneous CCD camera BUSCA at Calar Alto 2.2m
telescope, in Southern Spain. The filters used are Strömgren u,b,y and
Cousins I. The scaling between the different filters is arbitrary.
Field of view is about 12x12 arcminutes (approx. one third of the diameter of the full Moon).
Full resolution image (1.2 MB)
© Calar Alto Observatory, July 2006