Hemisphere:  Southern  ·  Constellation: Centaurus (Cen)  ·  Contains:  NGC 4945

Image of the day 07/13/2018

    NGC 4945, 


            Terry Robison
    NGC 4945
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    NGC 4945

    Technical card

    Imaging telescopes or lenses: RC Optical Systems RCOS 10" Ritchey-Chrétien

    Imaging cameras: SBIG STL-11000M

    Mounts: AP900GTO Astro Physics

    Guiding cameras: AOL + SBIG Remote Guide Head

    Filters: Baader Planetarium H-a  ·  Astrondon Astrodon

    Accessory: FLI CW2-7 Filter wheel 7

    Frames: 90x900"

    Integration: 22.5 hours

    Basic astrometry details

    Astrometry.net job: 2136142

    RA center: 13h 5' 26"

    DEC center: -49° 28' 48"

    Pixel scale: 0.804 arcsec/pixel

    Orientation: 59.575 degrees

    Field radius: 0.369 degrees

    Resolution: 2753x1836

    Data source: Own remote observatory

    Remote source: Non-commercial independent facility


    This is NGC 4945, a large barred spiral galaxy located in the constellation Centaurus. It is the second brightest galaxy in the subgroup centred on Centaurus-A with an apparent magnitude of 9.3, and an apparent size of 20’.0 X 3’.8. NGC 4945 is about 13 million light-years distant, and is almost the size of our own Milky Way Galaxy. Both X-Ray and infrared observations have shown unusual high energetic emissions and star formation at its core. Like all happy galaxies, a super-massive black hole is thought to exist at its centre.

    The data was a little tricky to work with, as it comes from 6 calibration streams (multiple cameras, all STL's), spanning about three years. Needless to say, it was a challenge to piece together.

    When I first combined the data, it had a distinct mauve and dirty brown look about it. This was really unusual I thought. No matter what I did, it was present, so I followed the numbers. I managed to collect a reasonable amount of Ha in the process, and decided to add that into the mix as well. The Ha filter allows emission data to be easily identified. Look for the pinks and reds throughout the galaxy to identify these areas.

    Ha 26 X 1200 Binned 1x1 - 8.66 hours
    Lum 34 X 900 Binned 1x1 - 8.5 hours
    Red 15 X 450 Binned 2X2 - 1.8 hours
    Green 14 X 450 Binned 2X2 - 1.7 hours
    Blue 16 X 450 Binned 2X2 - 2.0 hours
    Total hours 22.66

    Instruments Used:
    10 Inch RCOS fl 9.1
    Astro Physics AP-900 Mount
    SBIG STL 11000m
    FLI Filter Wheel
    Astrodon Lum, Red, Green, Blue Filters
    Baader Planetarium H-alpha 7nm Narrowband-Filter

    Disclaimer: All data is pure end-to-end own work from equipment through acquisition through processing.