2 November 2023

There’s an object in the sky that we can barely see through a telescope equipped with special filters. Even though it’s faint to us the Hubble Space Telescope assures us this object is six times larger than the moon.

The Cygnus Loop Nebula is the expanding remnant of a supernova explosion that occurred 5,000 to 10,000 years ago. The little we can see of it is beautiful, especially a portion of the veil called the Witches Broom, pictured at top and on the right side of the complete nebula photo below. (The bright star, 52 Cygni, is in both photos.) Click here for a large beautiful photo of the Witches Broom at NASA’s Astronomy Picture of the Day.

There is more to this nebula than meets the eye. In addition to visible light it’s emitting radio waves, infrared, X-rays and ultraviolet. Here it is in the ultraviolet range.

Since birds can see ultraviolet light the nebula probably looks brighter and better to them.

Space.com’s video shows the nebula’s size and location in the Cygnus constellation.

Six times larger than the moon!

If we could see what birds see, what would that look like? Here’s my best guess, by superimposing the nebula’s UV image next to the moon.

Moon at Thrissur (Wikimedia) + Cygnus Loop Nebula comparison

It’s amazing what we humans are missing.

(photos from Wikimedia Commons; click on the captions to see the originals)