Gazing into the Eye of a Cosmic Seagull

Stars form inside dense clouds of gas and dust. They start out as small eddies bound by mutual gravitation, and continue to grow more massive and hotter until, finally, a new star ignites:

The blue giant star HD 53367 dominates the center of Sh-2-292, causing the hydrogen in the nebula to glow a rich red color. Click to see the 1280×1275 version, or get the über-colossal 6554×6528 version.

Is that beautiful or what? This is an image of Sharpless 2-292, a region of a larger complex called the Seagull Nebula. It was taken by the 2.2-meter telescope at the European Southern Observatory’s (ESO) La Silla Observatory in Chile.

And what an image it is! At the center of Sharpless 2-292 is a bright star called HD 53367, a newly formed monster weighing in at 20 times the mass of our Sun! HD 53367 actually has a smaller companion star that is “only” 5 times more massive than the Sun. We can’t actually see the companion in this image because it too close to its giant, about 1.7AU* apart.

Still, this giant is having quite an effect on the surrounding nebula. HD 53367 is so bright it floods the gas in the surrounding nebula with so much radiation, it strips the hydrogen in the gas of their electrons. In other words, the hydrogen becomes ionized. Eventually, those electrons are recaptured by hydrogen ions and the gas glows a rich red color, much like a neon sign.

The nebula also features a dark lane of thick dust, which stands out in silhouette against the glowing hydrogen. But it’s not all dark – if you look closely at the image you’ll find that blue haze “hanging” about throughout the nebula. This is due to blue light from the star being scattered by tiny particles in the dust itself.

This nebula is really part of a larger complex called the Seagull Nebula:

Wide-field view of the entire Seagull Nebula (IC 2177) Credit: ESO/Digitized Sky Survey 2. Acknowledgement: Davide De Martin

HD 53367 and its immediate surroundings form the “head” of the Seagull (ok, use your imagination!).

What’s great about images like this – apart from their sheer gorgeousness – is that they give us a front-row seat to the process of star formation and their impact on the very nurseries in which they formed.


* An AU is short for Astronomical Unit, which is the distance between the Sun and Earth, so the two stars are separated by a little less than twice the Earth-Sun distance, which is too close to each other to be seen 3700 light-years from Earth.

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