Oregon Star Party, Ochoco National Forest, July 17 – 20, 2023

With a wide field telescope, it was possible to image both M8 and M20 in the same frame.  While M8 and M20 were very low in the sky, between 18 and 22 degrees, the transparency was excellent and the seeing was good enough with an image scale of 1.47 arcsec/pixel to capture a decent rendering.  I used Red, Green and Blue filters to capture the data and a 5nm Hydrogen-alpha narrowband filter to supplement the red channel to bring out more nebulosity and detail.  Image acquisition went well with a few hiccups due to operating a Mele Quieter 3C fanless Windows 11 PC using MS Remote Desktop on a new Apple iPad.  I made several image processing mistakes that resulted in colorful halos around small, light disks for the bright stars across the field.  This may have been caused by applying BlurXTerminator  to red, green, and blue masters before combining into an RGB color image.

The Lagoon nebula is a very bright and large hydrogen emission region and star nursery.  M8 was discovered in 1654 by the Italian astronomer Giovanni Battista Hodierna, who, like Charles Messier, sought to catalog nebulous objects in the night sky so they would not be mistaken for comets.  This star-forming cloud of interstellar gas is located in the constellation Sagittarius and its apparent magnitude of 6 makes it faintly visible to the naked eye in dark skies.  Located 5,200 light-years from Earth, M8 is home to its own star cluster, NGC 6530.  The massive stars embedded within the nebula give off enormous amounts of ultraviolet radiation, ionizing the gas and causing it to shine.

The Trifid nebula has it all, an emission nebula trisected by dark molecular clouds, and topped with a blue reflection nebula.  The dark dust filaments that lace M20 were created in the atmospheres of cool giant stars and in the debris from supernovae explosions.  Which bright young stars light up the blue reflection nebula is still being investigated.  The light from M20 we see today left perhaps 3,000 years ago, although the exact distance remains unknown.  Light takes about 50 years to cross M20. (NASA)

Imaging details:

Stellarvue SVX102T refractor with 0.74x focal reducer (FL = 528mm, f/5.2)
ZWO large off-axis guider with a ZWO ASI 174MM mini guide camera
Losmandy G11 mount with Gemini 2
ZWO ASI 2600MM Pro cooled monochrome camera (-5C)
Chroma 36mm Luminance, Red, Green, and Blue filters
Equatorial camera rotation: 90 degrees

Software:    Sequence Generator Pro, ASTAP plate solving, PHD2 guiding, 
    Losmandy Gemini ASCOM mount control and web client interface,
    SharpCap Pro for polar alignment with a Polemaster camera,
    PixInsight 1.8.9-1,
    Photoshop 2023

Hydrogen-a 10 min x 19 subframes (190 min), Gain 100, Offset 32, 1x1 binning
Red             2 min x 36 subframes (72 min), Gain 100, Offset 32, 1x1 binning
Green          2 min x 34 subframes (68 min), Gain 100, Offset 32, 1x1 binning
Blue            2 min x 34 subframes (68 min), Gain 100, Offset 32, 1x1 binning