Many of you may know that Betelgeuse is due to explode any day now, of course any day now in the galactic time scale could be long after I’m gone, I hope not. The opportunity to witness a major astronomical event is exciting all on its own, but when you consider the technology we have available to us today it becomes something altogether spectacular. What fantastic images could the Hubble Space Telescope provide if it were pointed at something like that?
We’ll have to wait and see.
In the mean time however, Hubble has already provided us a close (again, close in an astronomical sense) look at a different celestial spectacle you may not be aware of. If you’ve spent any time at all browsing Hubble images you’re probably familiar with V838 Monocerotis.
What you may not know is that this is a still image of a very recently active object, at least from our perspective. The variable red star is roughly 20,000 light years away so any observed activity is of course approximately that old. V838 was nested quietly in the constellation Monoceros, invisible to the naked eye and our best telescopes until, in 2002, it suddenly increased in luminosity becoming perhaps one of the biggest and brightest known Milky Way stars.
Hubble observed V838 over the next four years and what it recorded needs to be seen to be believed. The massive amount of light the star was producing (at peak approximately one million times that of our Sun) illuminated surrounding nebulous matter as it arced outward in all directions.
This phenomenon, known as a “light echo” occurs when light hits a cloud of gas and dust and is reflected back. From 2002 until 2006 the sphere of light continued racing outward at its fixed speed creating an expanding sphere of illuminated gas and dust. Despite it’s appearance, most of the gas and dust we see is actually behind the star, not in front of it.
Researchers are unsure what is causing the stars behavior, several hypotheses have been suggested though at this point it remains a mystery. I’m still waiting patiently for Betelgeuse to finally kick the galactic bucket, but this should hold me over for a while.