Astro -Thermography

[Atlas]

I have been tossing this idea in my head for awhile now. Has anyone else been considering this. I noticed there is a large price flux on thermal imaging cameras. Ultimately I want to take thermal shots of planets, but I also want to try my hand at detecting Brown Dwarfs.

Is this a known area of research in our hobby?

[Psychobilly]

Aren't the IR wavelenghts drastically attenuated by the earths atmosphere which is why IR telescopes are either in orbit or flown at extremely high altitude - NASA has a scope in a converted jumbo jet IIRC??

Peter...

[Atlas]

Aren't the IR wavelenghts drastically attenuated by the earths atmosphere which is why IR telescopes are either in orbit or flown at extremely high altitude - NASA has a scope in a converted jumbo jet IIRC??

Peter...

I have no idea to be honest about the interference. I do know of the Flying Laboratory though.

[Psychobilly]

It might be worth doing a bit of research on the net before purchasing any kit...

A quick google turned up this...

http://coolcosmos.ipac.caltech.edu/cosmic_classroom/ask_astronomer/faq/obs.shtml

Peter...

[Atlas]

It might be worth doing a bit of research on the net before purchasing any kit...

A quick google turned up this...

http://coolcosmos.ip...r/faq/obs.shtml

Peter...

I agree, I have no intentions of buying anything until I have a detailed picture of what's involved.

[Ben Ritchie]

I've used VISIR on the VLT, which is optimised for two mid infrared (MIR) atmospheric 'windows' between 8 to 13μm and between 16.5 and 24.5μm. That's at 2600 metres in the Atacama though, so far better conditions than you'd ever get in the UK.

There are technical challenges too, once you're in the thermal infrared you have to remember that both the atmosphere and the telescope itself are strong emitters at around 250K; it's roughly equivalent to trying to image in the optical during daytime with a telescope made of bright luminescent panels and a reflective but luminescent mirror. There are specific techniques to help deal with this ('chopping and nodding', for one) but it's rather different to optical imaging

[Ben Ritchie]

Here's a nice example

(Top) Four raw signal images

(Middle) "Chopped-Difference" images constructed from (signal1 - signal2) and (signal4 - signal3). The peak-valley variation is only 1% of the absolute signal

(Bottom) The final "Net Source Signal" image showing NGC 253.

slightly edited to remove counts to hopefully make it a bit clear - the important bit though is the background can be far larger than the source signal

[dph1nm]

You can probably do y-band imaging at about 900nm with a standard CCD from the ground. That should enable you to color-select the odd brown dwarf. Any more than that and you are in to specialist territory.

NigelM

[laser_jock99]

You could send your IR camera up with a helium balloon at night

The biggest technical problem would be keeping the camera stable (gyroscopes?). A kit may soon be available http://www.sentintospace.com/