The Dark Horse (Photo Release)


horse_head175The 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).
 
© Calar Alto Observatory, July 2006