Astronomy Picture of the Day: 06/01/2026

Object Name: Seagull Nebula

Copyright: Christopher Seaton

Location: Geraldton, Western Australia

Connect: NA

Skill level: Intermediate 2-4 years

Image Title

Seagull Nebula in SHO false-colour

Artists' statement

An image of the Seagull Nebula taken with narrowband filters, presented in SHO. Red represents Sulphur, green is Hydrogen, and blue is Oxygen.

How This Image Was Captured

Gear used

ToupTek ATR2600M Pro camera

RedCat 51 telescope

Sky-Watcher GTi mount

Exposure details

60-second exposures, 54 in Hydrogen-alpha, 56 each in Oxygen-III and Sulphur-II

Processing notes

Flats and darks for calibration, stacked and processed in PixInsight. Final image cropped down from full.

Exploring The Seagull Nebula

The Seagull Nebula (IC 2177) is an expansive emission complex lying roughly 3,800 light-years away, straddling the constellations Monoceros and Canis Major. Dominated by H II regions, its bright hydrogen gas glows under the intense ultraviolet radiation of embedded OB-type stars, while cooler molecular clouds trace dark lanes that thread through the nebula. Within this complex, several star-forming regions, including the clusters NGC 2335 and NGC 2343, are actively producing young, massive stars whose stellar winds and radiation sculpt cavities and shock fronts. The interplay between ionised gas and dust creates a striking contrast of red Hα emission and faint blue reflection nebulae. IC 2177 offers a textbook example of triggered star formation, where radiative feedback from massive stars compresses nearby clouds, potentially initiating the next generation of stellar birth.

Behind the Selection

This image was selected for its rich structural detail and dramatic contrast revealed through SHO mapping. The combination of sulfur, hydrogen, and oxygen channels highlights the intricate interplay of ionised gas and dust lanes, showcasing both the active star-forming regions and the sweeping cavities carved by massive stars. The image brings out the nebula’s full scale and depth, letting viewers appreciate the dynamic processes shaping this stellar nursery across thousands of light-years.