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Grasslands Observatory :
Interesting Objects with Common Names

Horsehead Nebula
The Horsehead Nebula (IC434)

There are many objects that have a common name(s) associated with them as well as their more formal catalog name(s). Some of these unusual and beautiful objects are pictured here. Many of these color images were first obtained with the 24-inch f/5 reflector at the Grasslands Observatory from 1996- to the present. They were initially taken either with a Spectra Source HPC-1 CCD camera or with an Apogee AP7 CCD camera. The HPC-1 contained a Texas Instruments chip with a 1024 x 1024 array of twelve micron pixels. The Apogee AP7 CCD camera contained a SITe 24 micron 512 x 512 CCD chip that had excellent quantum efficiency throughout the visible spectrum and into the near-infrared portion of the spectrum.

Exposures typically range from Red (R) = 1 minute, Green (V) = 1.5 minutes, Blue (B) = 2 minutes, and Open (O) or Clear (C) = 1-2 minutes to total exposures R = 30 minutes, Green (V) = 30 minutes, B = 60 minutes, and O or C = 5-60 minutes for the Dream Machine CCD camera. Short exposures are used for bright clusters, and long exposures are used for faint galaxies and nebulae. Most color imaging is performed using a Luminance technique with Open or Clear exposures used for the Luminance (L) part of the color composition.

In late 2007 a Quantum Scientific Imaging (QSI) 532 CCD was acquired with an LRGB filter set as well as a hydrogen alpha filter all residing in the QSI 532 internal color wheel.  The QSI 532 CCD has a Kodak KAF-3200ME 2184 x 1472 chip with 6.8 micron pixels.  This camera can give very high resolution images with the 24-inch telescope, but guiding is critical, and 2x2 binning is sometimes used for imaging.  Typical exposures for black and white pictures are 5-10 minute single exposures or three to ten 5-minute exposures median combined.  For color imaging, the black and white exposures are combined with 5 minute or longer exposures through red, green, and blue, or hydrogen alpha filters.

Recent equipment upgrades also include an 8-inch f/4 Meade LXD75 Schmidt-Newtonian telescope which has been mounted onto the side of the 24-inch telescope.  Imaging through the 8-inch telescope is done with a Canon 20Da or 60Da digital camera back, or the QSI 532 CCD camera. 

The Canon 20Da, Canon 60Da, or the QSI 532 can also be used with a Takahashi Epsilon 180 f/2.8 Astrograph which is sometimes mounted on the 24-inch telescope.


tbh 28 April 2014; revised 16 June 2016



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