WLM
Wolf-Lundmark-Melotte I

 

            
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This Local Group Galaxy
            outlier is extremely difficult to image due to its low surface
            brightness, extended size and low declination. Located on the
            border of Cetus and Aquarius, this 11th magnitude object is 12
            x 4 arcminutes in size and was first discovered in 1909 by Max
            Wolf. Its nature as a galaxy was only established in 1926 by
            Knut Lundmark and Philibert Jacques Melotte (1880-1961). Not
            only is WLM at the frontier of the Local Group, but it is also
            very isolated – its nearest neighbor, the dwarf galaxy IC
            1613, a full million light-years away. Quite elongated, with
            a largest extension of more than 8,000 light years, WLM is about
            12 times smaller than the Milky Way. Yet the discovery around
            it of many outlying red stars suggests that even such galactic
            minnows may have haloes and that WLM may be similar to our own
            galaxy in age.

            
Imaging this object
            is a challenge to say the least. Because it is very low on the
            horizon, the seeing dominates the quality. Here, stars have been
            resolved across the face of the galaxy, most dimmer than magnitude
            20. A lack of obvious HII regions in the RGB data shows the galaxy
            to be rather gas poor, however I do plan on some deep hydrogen
            exposures to be certain.

Instrument:  12.5" f/5 Home made Newtonian
Mount:  Astrophysics 1200 QMD
CCD Camera:  SBIG 10XME NABG with Enhanced Water Cooling
Guider: Meade DSI Pro  w/Lumicon Newt Easy Guider
Exposure:  LRGB = 80:20:20:20 (RGB Binned 2x2)
AstroDon RGB Combine Ratio:  1: 1.05: 1.11
Location:  Payson, Arizona, Elevation:  5150 ft.
Sky:  Seeing FWHM = 4.5 arcsec (Maxim DL - 10min subframe), Transparency 8/10
Outside Temperature:  30 F
CCD Temperature:  -30 C
Image Processing Tools: 
Maxim DL:  Calibration, deblooming (Starizona Debloomer), aligning, stacking
PixInsight:  Curves, Deconvolution, noise reduction
Photoshop CS2:  Curves, Color Correction, Gradient removal (Grad Xterminator), Cleanup

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