Saturday, March 22, 2008
What the f&*ck is that?
Perhaps a bit more clear than the GZ blog explanation of The Hanny's Voorwerp, this article from the Chandra X-Ray Observatory Press Room details the findings stemming from an earlier investigation of a supernova remnant now married with the results of 2 optical studies of a nearby gaseous cloud. What they studied was a phenomenon known as "light echo". Basically, there was a great big bang (supernova) in the past, that gave off light. We can see the remains of the supernova, but we have no way of quantifying the amount of light given off by the supernova event, other than an estimation from it's remnant. In the Chandra/XXM study, they went a step further and focused their attention on a dusty cloud, not too far from the supernova and found the reflection of the supernova, or it's "light echo". All they had to do was decide how long ago the explosion was and find something that would reflect the light and was also a certain distance away from the supernova. That distance being the distance it would take light to travel from the supernova to the reflecting object in the time since the explosion.
So, see the remnant of an explosion that happened 400 years ago. Find an object 400 light-years from the explosion and it should be reflecting the light from an explosion 400 years ago, right now. In truth, it's a wee bit more complicated than that, when you factor in the distance between us and the remnant and more importantly, the distance between us and the reflecting remnant, but in a nutshell, that's the very cool phenomenon of "light echo". A cosmic fossil if you will. Any geologists, or paleontologists out there should really appreciate the coolness factor of a true cosmic fossil.
Now, back to The Hanny's Voorwerp. Her object is another just another dusty, gaseous cloud, but oddly, a deep blue. She noticed it was VERY blue, bluer than the thousands of galaxies she'd classified and lacked any definable stars, star forming regions, or the shapes and structure we've come to recognize after classifying so many galaxies. Curious, she posted on the GZ forum, asking if anyone knew what it was. Nobody knew. Many theories, but no answers. The closer they looked at things like it's spectrum, the stranger it became. Finally, astronomers and astro-geeks realized it was unique and needed to be studied, now. Proposals went out to several of the world's largest and most powerful observatories, including HUBBLE.
Preliminary results have identified the Voorwerp as a dusty, gaseous cloud reflecting the light from a long-gone Quasar! Scientists estimate it existed 50,000-75,000 years ago, somehow disappeared from view and we're seeing it's light reflected in a space cloud today. From this, we should be able to go back in time and as this reflected light plays like a movie for us, determine how the missing Quasar met it's end. That, my friends is a pretty amazing result of an ordinary person finding a blue blob in an image posted on a website and wondering aloud what it is.
In the spirit of The Hanny's Voorwerp and identifying heretofore unknown objects, I'll post an image and ask if anyone (besides mr bud and PW!) can identify exactly what it is?