#barnard's loop

Orion at Cowcowing Lakes, Western Australia

Barnard's Loop

It's likely you'll be fairly familiar with the constellation of Orion in the night's sky, whether you view it from the Northern or Southern Hemisphere it's easily identifiable by the 3 stars, the belt of Orion, with Betelgeuse and Rigel, large bright stars either side of it.

The human eyes can even detect a fuzzy area just below the three stars, M42 Orion Nebula, best seen by not looking directly at it, but just off to the side in what we call Averted Vision.

But what our eyes cannot see, is that Orion is covered in a huge nebulous region of hydrogen gas, it's only 1,500 light years from us, making it the closest star forming area to Earth.

In the top image, you can see the extent of the gas and dust, stretching far beyond the belt of Orion, and forming what appears to be a loop like structure, known as Barnard's loop.

Astronomers have long argued how such a loop was created in the first instance, but recent evidence appears to point towards a "recent" supernova, 4 million years ago in a cluster of stars known as OBP-B1.

You can see a visualisation of the area here which lets you zoom in and out.

It gives you a small indication of the power of supernova, carving out huge voids in hydrogen gas, creating bubbles, but also shock waves as the pressure pushes out against the gas, and in doing so, creating clumps and areas where future stars can be born.

Source :

Barnard's Loop

From Astronomy Picture of the Day; October 14, 2018:

Orion in Red and Blue David Lindemann

Orion constellation