Farnham Astronomical Society » Donal McDonnell http://www.farnham-as.co.uk The Farnham Astronomical Society was founded in 1971 by a group of keen local amater astronomers to further interest in the night sky and all things astronomy. Tue, 27 Jul 2010 12:46:20 +0000 en hourly 1 http://wordpress.org/?v=3.0 Horsehead and Flame Nebulae Imaged by Donal McDonnellhttp://www.farnham-as.co.uk/2009/08/horse-head-nebula-imaged-by-donal-mcdonnell/ http://www.farnham-as.co.uk/2009/08/horse-head-nebula-imaged-by-donal-mcdonnell/#comments Mon, 17 Aug 2009 11:21:40 +0000 pcburns http://farnham-as.co.uk/?p=643 The Horsehead Nebula (Barnard 33) is a dark nebula in bright nebula IC 434, in the constellation of Orion.  The Flame nebula can be seen to the bottom left of the image.

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 mostly by thick dust.   The bright red emissions are evidence of ionized hydrogen (HII regions).  UV light is ionising clouds of molecular hydrogen; when the ionised hydrogen returns to the ground state the energy of this transition yields a wavelength of 6563A. This is in the visible red light spectrum. HII regions are known to have very strong H-Alpha

Lookup the Horsehead Nebula on SEDS

DM_Large_Horse

Horsehead nebula by Donal McDonnell - click to enlarge

Image taken using an Atik16HR and Takahashi FSQ106ED at F3.8 mounted on an EQ6 (with EQMOD) and guided with an ST4 on on an ED80.

  • Ha 110m (11 x 600s)
  • Lum: 41m
  • Red: 21m
  • Green 21m
  • Blue 26m.

]]> http://www.farnham-as.co.uk/2009/08/horse-head-nebula-imaged-by-donal-mcdonnell/feed/ 0 Orion Nebula (M42) Imaged by Donal McDonnellhttp://www.farnham-as.co.uk/2009/08/orion-nebula-m42/ http://www.farnham-as.co.uk/2009/08/orion-nebula-m42/#comments Sat, 08 Aug 2009 18:34:31 +0000 Richard Kacerek http://farnham-as.co.uk/?p=125 The exposure details / channel assignments are as follows:

  • Ha= 25m (R)
  • SII = 35m (G)
  • OIII = 35m (B)

Taken on Takahashi FSQ106ED at F5 with an SBIG STL6303 CCD and Astronomic Filters.

Click here for a larger image.

DM_M42Dec08

]]> http://www.farnham-as.co.uk/2009/08/orion-nebula-m42/feed/ 0 Heart Nebula (IC 1805) Imaged by Donal McDonnellhttp://www.farnham-as.co.uk/2009/08/heart-nebula-m42/ http://www.farnham-as.co.uk/2009/08/heart-nebula-m42/#comments Sat, 08 Aug 2009 18:32:00 +0000 Richard Kacerek http://farnham-as.co.uk/?p=122 Exposure details:

  • Ha 2h45m
  • SII 8h
  • OIII 8h30m

Camera STL6300, Telescope FSQ106ED, Mount EQ6. Processed in CCDStack.

Click here for larger image

DMic1805

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