Rho Ophiuchi Cloud Complex
A widefield DSLR Lens Astrophotography test of the large beautiful Rho Ophiuchi Cloud Complex with the wispy Blue Horsehead Nebula (IC 4592) visible in the top left (using a standard unmodified Nikon D750 and Nikon 105mm Lens without any filters).
The Rho Ophiuchi Cloud Complex:
Rho Ophiuchi is a dark nebula of gas and dust that is located 1° south of the star ρ Ophiuchi of the constellation Ophiuchus (close to the red Supergiant star Antares).
About the Interstellar Cloud Colors:
Fine dust illuminated from the front by starlight produces blue reflection nebulae. The atoms of gaseous clouds that are excited by ultraviolet starlight produce reddish emission nebulae. Back-lit dust clouds block light and appear dark. Antares (a red Super-giant star, and one of the brighter stars in the night sky), lights up the yellow-red dust clouds. Rho Ophiuchi lies at the center of the blue nebula. Interstellar clouds are even more colorful than we can see in visible light, emitting light across a large portion of the electromagnetic spectrum.
About this image:
While I was imaging a closer view of the Cloud Complex with my Telescope, I literally just pointed the D750 at the red Supergiant star Antares, and set the Intervalometer to shoot 3 minute exposures at ISO 1600. I used my Nikkor-Micro 105mm f2.8 Lens (stopped down from f/2.8 to f/4).
A BIG thank you to Nikon South Africa for letting me test their D750 for my latest Astrophotography events in Southern Africa.
Nikon D750 DSLR.
Nikon AF-S VR Micro-Nikkor 105mm f/2.8G IF-ED (N Series) Lens.
Hahnel Giga T Pro II 2.4GHz Wireless Remote for Nikon.
Orion StarShoot Autoguider (with PHD Guiding).
Orion Mini 50mm Guide Scope.
Celestron SkySync GPS Accessory.
Celestron AVX Mount.
35 x 180 sec. ISO 1600 RAW (NEF) exposures.
30 x Bias
20 x Darks
Pre-Processing and Linear workflow in PixInsight,
and finished in Photoshop.
Center RA, Dec: 247.865, -23.181
Center RA, hms: 16h 31m 27.671s
Center Dec, dms: -23° 10' 52.726"
Size: 14.1 x 10.9 deg
Radius: 8.922 deg
Pixel scale: 31.8 arcsec/pixel
Orientation: Up is 90.8 degrees E of N
View an Aannotated Sky Chart for this image.
View this image in the World Wide Telescope.