We just got back from a little time away in Colorado. ‘Twas nice to be there, but is nice to be back home and in the saddle. So, to celebrate, here’s a picture from the Hubble Space Telescope.

HST imaged the Red Rectangle some years ago in lower resolution, and returned to it again to capture more details at higher resolution. Now, it’s not really a rectangle, but is shaped more like a fuzzy X. What’s causing the X-star? The star in the center of the Red Rectangle is one that began its life as a star similar to our Sun. It is now nearing the end of its lifetime, and is in the process of ejecting its outer layers to produce the visible nebula. The shedding of the outer layers began about 14,000 years ago.

So, what’s with the ejection of the outer layers? Dying stars like the Sun (and all dying stars, really) go through a process called “mass loss” which involves large amounts of stellar material flowing away from the aging star. In this case the outflows are ejected from the star in two opposing directions. The most amazing thing about this picture are the straight features that appear like rungs on a ladder. These rungs could have formed during successive episodes of mass ejection from the star that have happened like clockwork every few hundred years.

In a few thousand years, the star will have become smaller and hotter, and will begin to release a flood of ultraviolet light into the surrounding nebula; at that time, gas in the nebula will begin to fluoresce, producing what astronomers call a planetary nebula.