"And therefore I have sailed the seas and come
To the holy city of Byzantium. 
O sages standing in God's holy fire
As in the gold mosaic of a wall,
Come from the holy fire, perne in a gyre,
And be the singing-masters of my soul.”
– W.B. Yeats

A majestic black stallion rears atop a misty ridge, its silhouette cast in bold relief against the glowing sky. The air is thick with ethereal tendrils of fog that curl around the nearby hills, as if the land itself is draped in a veil of gossamer. The sunlight dances across the landscape, casting long shadows behind the hills and illuminating the clouds in a golden halo. The water of the bay shimmers and glows, rippled by delicate filaments of light that flicker like flames on its surface.

Whenever I look at deep sky images, whether they are nearby nebula or distant galaxies, I tend to think in terms of “how long ago” rather than “how far away”, or “when” rather than “where”.  Maybe it’s because I love history almost as much as I love science.  The light captured in the image above originated in a massive cloud of gas and dust in the Orion Arm of the Milky Way galaxy some 1,750 years ago, when the great city of Constantinople (present day Istanbul), heart of the Byzantine empire, was still relatively young.  Known as the Orion A molecular cloud, it is one of the most active and well-studied star-forming regions in our galaxy and home to some of the most famous and recognizable celestial objects.  The image we are seeing here started its journey during an era in which artisans and craftsmen were working on the elaborate mosaics that adorn the Hagia Sophia; when this capitol of the Eastern Roman Empire was besieged on successive occasions, and “Greek Fire” was in use for the first time.  At its height the famous Hippodrome of Constantinople hosted chariot races for over 30,000 cheering spectators.  Perhaps this “Horsehead” is a monument to the great steed of a champion charioteer?


Astronomers know that the “stallion” in this image is a dense cloud of dust and gas nearly four light-years in length, erupting out of a ridge of glowing ionized hydrogen gas illuminated by energetic stars of the nearby σ (Sigma) Orionis cluster, above the horsehead, toward the upper part of the field of view.   At the center of it all is the brilliant Alnitak with its halo, one of the three bright stars of Orion’s belt.  Just below that is the brightly burning Flame Nebula, with its thick tendrils of smoky dust snaking through and obscuring the surrounding emission nebula.  A couple of reflection nebula are also visible – the bluish glowing NGC 2023 just below Horsehead, and IC 432 farther to the left.


I’ve always been fascinated by the Horsehead – there is something ethereal about it.  When I first started into astrophotography just two years ago, it was the second DSO I tried to image, after the Orion nebula itself.  I’ve often come back to it but given the ubiquity of images of this distant object on Astrobin and elsewhere, I’ve reached the point where I kind of feel like I’ve seen it all before, and I began to lose interest in it.  For this image I captured 26 hours of narrowband data (Ha, OIII, and SII), hoping to get enough detail that I could crop it and focus attention on the area immediately surrounding the dark nebula.  In processing it, I used BXT for the first time to deconvolute and reduce star size. I applied the Forax technique in Pixelmath to combine the narrowband channels in RGB, then used Ha as a Luminance channel. I tweaked the curves to bring out a sunrise/sunset vibe that feels, at least to me, very natural.  Alnitak is a bit annoying – the halo effect is a little distracting, and I also might have gone overboard with star reduction – but overall, I really like the way the image turned out.  It almost feels like an oil painting to me and is easily one of the most detailed images I have produced yet. 

Friends often ask me about the images I share (and about other Astro images, such as Hubble images and JWST) whether the colors are “real” – as in, is that what the object really looks like, or did I just paint them whatever random colors I wanted to so it would look pretty?  Here’s the way I see it: centuries before the Impressionists set brush to canvas and reinvented the way that artists think about light and color in capturing the essential nature of the world around us, this spectacular show of light and shadows from one of the most breathtakingly beautiful star-forming regions visible from our planet played out on a cosmic-sized canvas. I’ve often thought that modern astrophotography is as much akin to impressionist art as it is to science.  John Ruskin, a British art critic and influential writer during the early Impressionist era argued that artists should strive to capture the "truth" of nature rather than just copying what they saw.  Likewise, contemporary astronomers aim to uncover fundamental truths about our cosmos, even when the process of translating these truths to something that is visible to the human eye and comprehensible to the human mind often requires sifting the faintest of signals from the noisiest data and stretching and shaping those signals on a palette of human technology.  What a shame it would be if such exquisite detail were to remain hidden from us just because our eyes did not evolve to see all of the colors of the invisible spectrum that makes up our physical universe! 

Here is my first try, Feb 2021, just 10 minutes total exposure time, taken with my William Optics ZenithStar 73 refractor and an astro-modified Nikon DSLR.