Astrophotography allows us to peer into the universe in extraordinary detail, revealing the beauty and complexity of regions far beyond our solar system. Today, we’re excited to dive into one of our latest images: the Elephant Trunk Nebula (IC 1396A) and the mysterious OU4 Nebula, captured in stunning SHO (Sulfur II, Hydrogen-alpha, Oxygen III) narrowband filters. Imaging for nearly 40 hours, we’re able to capture detail and resolution that is astounding and great to work with – we love seeing what our members have done with this data! The Elephant Trunk Nebula and OU4 prove to be fascinating targets and challenging to compose in a single field of view but we feel our data does a great job letting us bring out amazing detail and structure.
Image Acquisition details:
Acquired from our dark sky observatory on:
Dates:
July 8, 2024
July 10 – 16, 2024
July 24 – 25, 2024
Frames:
Antlia 3nm Narrowband H-alpha 2″: 174×300″(14h 30′)
Antlia 3nm Narrowband Oxygen III 2″: 178×300″(14h 50′)
Antlia 3nm Narrowband Sulfur II 2″: 104×300″(8h 40′)
Integration:38h
What is the Elephant Trunk Nebula?
The Elephant Trunk Nebula, part of the larger IC 1396 emission nebula, is located about 2,400 light-years away in the constellation Cepheus. Discovered in 1899 by American astronomer Edward Emerson Barnard, this dense, elongated cloud of gas and dust is a stellar nursery—an area where new stars are born.
The “trunk” shape of the nebula, which gives it its name, is the result of interstellar winds and radiation from nearby hot, young stars pushing against the cloud. Inside, new stars are forming, their light slowly eating away at the surrounding gas and dust. The region is rich with ionized hydrogen, which glows in deep reds when captured in narrowband imaging. When combined with data from Sulfur (SII) and Oxygen (OIII), the nebula comes alive in a rainbow of colors that highlight its structure.
What’s Happening with OU4?
One of the more intriguing features in this image is the OU4 Nebula, discovered in 2011 by French amateur astronomer Nicolas Outters. OU4, also known as the “Giant Squid Nebula,” is a rare bipolar outflow nebula within the same region as the Elephant Trunk Nebula. It is believed to be an oxygen-rich outflow, most likely ejected by a triple star system at its core.
OU4 is notable because of its unusual shape and faint structure. The oxygen in the nebula emits light in the OIII wavelength, glowing a faint teal when captured with narrowband filters. This massive outflow structure stretches about 50 light-years across, making it an impressive but challenging target for astrophotographers.
Imaging with Antlia Pro 3nm Filters
This image was captured using Antlia Pro 3nm SHO filters, which allow us to isolate specific wavelengths of light emitted by ionized Sulfur, Hydrogen, and Oxygen gases in the nebula. By using these narrowband filters, we can highlight the fine details of the nebula and create an image with vibrant contrast and rich color that wouldn’t be visible to the naked eye.
The imaging setup included a William Optics RedCat 51 paired with a high-resolution 6200mm camera, offering the ability to capture these delicate structures in crisp detail. The resulting image reveals the Elephant Trunk Nebula’s glowing gas pillars and the faint, otherworldly tendrils of the OU4 Nebula.
Why This Region is Special
What makes the Elephant Trunk Nebula so fascinating is its role in star formation. The dense clouds within the trunk hide young, hot stars, which gradually blow away the surrounding gas and dust, creating cavities and triggering further star formation in a process known as sequential star formation. This region of space is a dynamic and evolving stellar nursery, providing astronomers with insights into how stars like our Sun are born and develop.
OU4 adds another layer of intrigue, as the nature of this outflow nebula and its interaction with the surrounding region is still a subject of study. Its enormous size and faint glow make it difficult to observe, but its discovery highlights how much we still have to learn about the complex processes taking place in nebulae like IC 1396.
Process Your Own Version of This Image
One of the best parts of astrophotography is sharing data with others so they can explore these regions of space on their own. At SadrAstro, we’re offering a chance for you to download the raw data from this image and try your hand at processing it. Whether you’re new to narrowband imaging or a seasoned astrophotographer, this data set will provide a fun and challenging opportunity to work with SHO filters and deep-sky objects.
Observatory Membership
Choose an affordable $149/year Annual Membership or select our one-time $299 perpetual lifetime plan and get full access to our existing and future imaging library, 100GB of personal storage & more!
We’re always happy to take interesting frames and custom observation requests from our members! Join today and let us know what you’d like to image next!
