The Horsehead nebula in Orion

Back in the '80s, when I was a kid, I remember to be totally amazed with a photograph of the Horsehead and Flame nebulas made by David Malin with the AAO (Anglo-Australian Observatory). The book also included a portrait of Malin, with the photographic plate camera behind him, inside the prime focus cage of the AAO telescope where he 'rided' all night long, making the long exposures. I recall that I thought he looked like an astronaut in a small chamber of a spaceship. Years after, I realized that was completely true.

Here is a humble tribute to his work. Humble by today's standards, but that little boy wouldn't have believed he would made this astrophotograph some ("sooome"??!) years after.

The Horsehead is a dark molecular cloud, Barnard 33, overlapping the HII region IC 434 (yellowish to red, here, due to the varying contribution of the sulfur emission). The overwhelming star is Alnitak or Zeta Orionis, the easternmost star of the Orion's Belt asterism. Under Alnitak is the Flame nebula, or NGC 2024. The prominent nebula under the Horsehead is NGC 2023, the brightest of several reflection nebulae portrayed in the image. 

Captured under city sky with narrowband filters, this was a tough one especially due to the challenging [O III] data. Weak signal even with 600 seconds subframes, and quite bright background gradient, not to mention the multiple reflections and scattered light of the brighter stars. The noisy, good old KAF-8300 sensor seems now like a photographic plate compared to the pretty cool CMOS out there, but that also contributed to the nostalgic or even romantic feeling while working on this image. Hope you like it.

Hα : 47x 600s
[O III]: 115x 600s
[S II] : 37x 600s

Dates: 2021-11-16, 2021-11-17, 2021-11-18, 2021-12-05, 2021-12-06, 2021-12-07, 2021-12-30, 2021-12-31, 2022-01-02, 2022-01-08

North is left.