Takahashi FSQ106N Refractor @ f5
SBIG Colour Filter CFW-10
MaxIm DL V4.07
25 November 2005 - 15 January 2006
0% - 20% Moon phases, mag 4.5 sky
Low altitude at this site.
SII and OIII = 8 exposures each @ 20 min 1x1 binned. Sub-exp ratios
CCD Temp @ -20°C
Raw Ha, SII and OIII narrowband filtered
images, Dark, Bias, Flat and Flat Dark frames acquired, reduced &
combined in MaxIm
All images Sigma clip combined, de-bloomed and stretched in FITS Liberator.
HaSII and OIII masters combined and finished in PhotoShop CS.
The Hubble false colour scheme was used to bring out the finer details:-
R=SII, G=Ha, B=OIII. Light
layer mask blend in PhotoShop CS to smooth background. No other processing
except removal of hot pixels not picked up at the combining stage.
lower image uses the same master Ha, OIII and SII images but re-weighted
in MaxIm's colour combine to strengthen the OIII contribution.
In this mix Ha=R, SII=G and OIII=B.
IC 434 (Horsehead), Barnard 33
NGC2024 (Flame Nebula) Lower left of image
RA and Dec
Dec: -02° 23' 40"
Highest Altitude at This Site
Est 1500 light years.
Size & Magnitude
Horsehead: 2.7 x 1.8 light years.
Magnitude n/a - dark nebula
What it is
The Horsehead Nebula in Orion is part
of a large, dark molecular cloud. The horse head shaped dark cloud is
also known as Barnard 33. The red glow originates from hydrogen gas
predominantly behind the nebula, ionized by the nearby bright star Sigma
Orionis (Alnitak) - the brightest star in the image. The darkness of
the Horsehead is caused mostly by thick dust, although the lower part
of the Horsehead's neck casts a shadow to the left .Streams of gas leaving
the nebula are funneled by a strong magnetic field. Bright spots in
the Horsehead Nebula's base are young stars just in the process of forming.
Light takes about 1500 years to reach us from the Horsehead Nebula.
The Flame Nebula to the lower left is part of the same Orion Molecular
Cloud Complex, a star-forming region that includes the Horsehead Nebula.