Hemisphere:  Southern  ·  Constellation: Ophiuchus (Oph)  ·  Contains:  IC 4592  ·  IC 4601  ·  IC 4603  ·  IC 4604  ·  IC 4605  ·  M 4  ·  NGC 6121  ·  Part of the constellation Scorpius (Sco)  ·  The star 13Sco  ·  The star Al Niyat (σSco)  ·  The star Antares (αSco)  ·  The star Graffias (β1Sco)  ·  The star νSco  ·  The star τSco  ·  The star χOph  ·  The star ω1Sco  ·  The star ω2Sco  ·  The star ωOph  ·  rho Oph Nebula
Rho Ophiuchi and the Blue Horsehead, 


            Mark Forteath
Rho Ophiuchi and the Blue Horsehead
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Rho Ophiuchi and the Blue Horsehead

Rho Ophiuchi and the Blue Horsehead, 


            Mark Forteath
Rho Ophiuchi and the Blue Horsehead
Powered byPixInsight

Rho Ophiuchi and the Blue Horsehead

Technical card

Imaging telescopes or lenses: William Optics Star 71 II

Imaging cameras: Nikon D750

Mounts: SkyWatcher EQ6R Pro

Guiding telescopes or lenses: William Optics 50mm Guidescope

Guiding cameras: ZWO ASI290MC

Software: PixInsight  ·  DeepSkyStacker (DSS) deepskystacker  ·  PHD 2  ·  APT  ·  Adobe Systems Inc. Photoshop CC 2019

Accessory: Orion Dew Zapper Orion Controller and Heating Bands

Dates:Aug. 9, 2020

Frames: 1162x60" (19h 22') ISO3200

Integration: 19h 22'

Darks: ~80

Flats: ~80

Bias: ~80

Avg. Moon age: 20.18 days

Avg. Moon phase: 70.31%

Bortle Dark-Sky Scale: 3.00

Temperature: 2.00

Basic astrometry details

Astrometry.net job: 3747947

RA center: 16h 30' 28"

DEC center: -23° 30' 36"

Pixel scale: 3.621 arcsec/pixel

Orientation: 90.970 degrees

Field radius: 8.697 degrees

Resolution: 12992x11409

Locations: Home Observatory, Wynyard, Tasmania, Australia

Data source: Backyard


Well here is the photo I am most proud of in my 5+ years of astrophotography so far. This is the Rho Ophiuchi complex with the Blue Horsehead to the left. Imaged over the last 3 months on every clear moonless night I could get, this is a total of 1162 images over a total of 23 tiles stacked and combined. Imaged through a William Optics Star 71 II APO on a Sky-Watcher EQ6-R Pro mount with a Nikon D750 unmodified dslr camera.

Initially I set out to image just Rho Ophiuchi but quickly realised there was a lot more to get in the fringes to do it justice. I must thank Angie for the encouragement and understanding through the many nights I spend on this project.

The colorful clouds surrounding the star system Rho Ophiuchi compose one of the closest star forming regions. Rho Ophiuchi itself is a binary star system visible in the blue reflection nebula in the image center. The star system, located only 400 light years away, is distinguished by its multi coloured surroundings, which include a red emission nubula and numerous light and dark brown dust lanes. Near the right of the Rho Ophiuchi molecula cloud system is the yellow star Antares, while a distant but coincidentally superposed globular cluster of stars, M4, is visible just above Antares. On the image left lies IC 4592, the Blue Horsehead nebula. The blue glow that surrounds the Blue Horsehead's eye, and other stars around the image, is a reflection nebula composed of fine dust. This is an incredible piece of sky with so much going on.

The image in its full resolution is 4.67m x 4.10m. I've had to reduce that considerably to make it fit here.


Sky plot

Sky plot


Rho Ophiuchi and the Blue Horsehead, 


            Mark Forteath