Whilst you were sleeping: Asteroid 2008 TT26 – a close encounter.
Hello
At midnight, on 23rd October I began my lonely vigil, hunting for Minor Planet 2008 TT26, a Near Earth Asteroid listed on SpaceWeather as being 70m in diameter, scheduled to pass with 3.6LD from our home, planet Earth.
Well, well, well; what I hadn’t anticipated was the frantic pace set by this 70m asteroid, as it zoomed through my field of view! Here is the trail, captured on 15 frames of 60 sec exposure each, with a gap of approx 26 sec between exposures.
Celestron C9.25 F10 SCT with F6.3 Reducer/Corrector.
SBIG ST7e CCD camera (765x510 pixels)
15 frames, 60 sec exposure per frame.
Brisbane, QLD, Australia. 23 Oct 2008, 14:38:07 to 14:58:34 UT. (24th Oct 2008, 12:38am to 12:58am AEST (UT+10)
Later that morning, having seen the animation, my wife humoured my efforts, thanking me for keeping watch on the fast approaching lump of rock whilst she had slept soundly, glad that someone was looking out for planet Earth!
Nice one Dennis! It sure was moving! I took a few shots of Vesta last night (first asteroid for me, but not in the same league as those that you're imaging!!!), and I'm planning on putting together a bit of an animation of its movement over the next few nights as it approaches opposition.
At midnight, on 23rd October I began my lonely vigil, hunting for Minor Planet 2008 TT26, a Near Earth Asteroid listed on SpaceWeather as being 70m in diameter, scheduled to pass with 3.6LD from our home, planet Earth.
Well, well, well; what I hadn’t anticipated was the frantic pace set by this 70m asteroid, as it zoomed through my field of view! Here is the trail, captured on 15 frames of 60 sec exposure each, with a gap of approx 26 sec between exposures.
Dennis
Hi Dennis,
Beautifully captured! Well done.
I used to keep an eye on the NEO list on Spaceweather too a few years back and I've caught
a few on modified webcams.
One of my easier ones was Toutatis, simply because it was due to
go right past Alpha Centauri, so there was no chance I could miss that
by imaging the wrong bit of sky! http://mywebsite.bigpond.com/astrost...s29sep2004.jpg
It was about mag 9, but because I was tracking the stars and not the
asteroid, same as yourself, the object is dimmer and , of course, will
be a trail.
The only way I could see was to do an EXTREME histo stretch and
make it a negative.
You can just make it out, a very faint grey line.
(not to be confused with the paste artifacts around the arrows )
Also, because of the stretch, you can see the dark holes as well.
I usually plan more carefully for these events and plot the position and expected trail of the asteroid using The Sky 6 Professional. However, this one almost caught me out as I hadn’t really planned for this session specifically. I had a general plan to image some small galaxies, but a tree was in the way of my 1st target so whilst waiting, I jumped on the web to have a look at the asteroid action on SpaceWeather and lo and behold, 2008 TT26 was due to make its fly by that very evening! The SpaceWeather website is a great resource for these NEO’s.
Modifying my plans for the evening, I used The Sky 6 Pro to download the orbital elements, crossed my fingers and did a “Find” object and it showed that TT26 would indeed be above the horizon later in the evening – often these objects are below the horizon so it was nice to find this one getting up to around 40 degrees altitude around midnight.
As the hour approached, I had CCDSoft (camera control software) and The Sky 6 Professional running on the Notebook, with The Sky 6 zoomed in to show the field of view of my CCD chip. I kept hitting the “Time” update button as TT26 approached the FOV indicator whilst manually flicking to the live image in CCDSoft to compare the field stars. It was quite amazing (and reassuring!) to see the live TT26 pop into the CCD frame at the place and time as displayed by The Sky 6 simulation! These tools are simply fantastic.
What I hadn’t really expected was the pace of this fella, so I had to grab some quick images to establish the optimum exposure, then leap frog ahead of the rock to begin capturing the trail. A couple of test exposures of 2 and 5 minutes recorded a much fainter tail, as the skies are quite light polluted in that direction (grrr!) so the sky background began to swamp the faint, extended trail. The optimum exposure seemed to be 1 minute so I grabbed 40 frames and of these, TT26 was in 15 of them.
The extra frames were grabbed so I could stack the images to get a smoother background for the animation, to mitigate some of the effects of the horrid light pollution and noise from such short exposures. Whilst my wife is very supportive of my hobby, she still has a somewhat bemused look on her face when I tell her of my latest cosmic exploits!
Dennis, you'll be pleased to hear that my wife said "wow" upon seeing your animation. I think people who aren't thrilled by such images don't have a 3D mental image of the solar system, so to them it's just a line on a picture. Well done.
We’ve been away on a camping holiday for a few days and I have just returned to find these posts – many thanks for your kind words of appreciation and encouragement.
nice work Dennis 
