Catching the Tail of a Meteor
This is what you missed last night
Time to take a break from the “dreary science”, i.e., economics.
One of my other hobbies is astro-photography. I have two telescope systems, one in Aspen, Colorado, the other one in San Diego. You will be surprised how many good images I have captured on my driveway in coastal San Diego with its still air.
Both systems are configured exclusively for taking pictures, you can see samples of my work at:
Last night was the peak of the Geminids Meteor shower, so I decided to capture some meteors.
First step was setting up my Canon EOS 6D outdoors where I had a northerly view of the constellation Gemini. I wanted each 30 second picture to be the same part of the sky, so the camera had to be mounted on a tracker. I use an iOptron Sky Tracker, which is then mounted on the tripod.
I think that the air temp was about 15 deg F.
Set the camera ISO to 2000, and used a 24mm wide angle zoom lens with the aperture set at the minimum f stop of 1.4, meaning that the opening was wide as possible, letting in as many photons as possible. This does make focusing more sensitive, so I used the “live view” mode at 10X zoom to manually adjust my focus.
The histogram of a test 30-second image confirmed that my settings were good, plenty of gathered photons, no saturation.
Final step was using the remote timer to tell the camera to take 30-second images over and over.
An hour later I checked the camera and saw that it was covered in frost. Temp was now about 10 deg F. Darn. Note to self, next time put a heated strap on the camera. Expecting the worst, I took the camera inside and inspected the images.
The good news is that the lens was not covered in frost for most of the images, and a quick scan showed that I had captured a few meteors, plus some airplanes and satellites.
This is what a raw image looked like:
While I did capture that meteor on the left, “a pretty crappy picture Eric”, might be your first thought. No problem, time to apply my post-processing magic (a software package called Pixinsight), which converts a crappy image to something like this:
Nice. The Milkyway is quite defined, those red blotches are nebula’s, and the small group of stars in the upper right is the Seven Sisters, otherwise known as Pleiades.
The stars being small and round tells me that the focus and sky tracking were both spot-on.
I then processed the next 30-second image, this is what I saw:
Hello! What is that red thing where the meteor was 30 seconds ago? Has to be a contrail from the passing of the meteor! Sun reflecting of the dust trail or glowing energized air? I honestly do not know, but suspect the latter as the sun had set some time ago.
I knew what I had to do next, take the next several images, process them all, crop them all, and make a short movie.
And this is it:
And that is what most of us missed last night, what the meteor left behind.
Eric
