Photometry

[rustigsmed]

Hi all,

I am almost certain I want to get into photometry with the view of detecting/measuring exoplanet transits.

I have a few questions.

What type of camera will I need? I have heard of amateurs detecting transits with dslrs and even simple planetary cameras. I assume for the data to be taken more seriously as a measurement a cooled mono ccd is a must?

What type of software will I need? I have heard Maxim DL can be used? Which is best / easiest? Maxim, SIP, Mira AL?

What else do I need (apart from patience)? A way to record precise UT? filter to cut out blue light?

Any other tips things to be aware of?

It seems to me that right now is a great opportunity for amateurs to contribute to exoplanet science with the possibility of even discovering a planet. In another 10-20 years there will probably be more spacecraft/professional programs out there sucking up all the discoveries.

Cheers,

Russell

[malclocke]

Russel, have a look at Bruce Gary's free book 'Exoplanet Observing for Amateurs', it will probably answer most of your questions.

http://brucegary.net/book_EOA/x.htm

Malc

[rustigsmed]

thanks malc,

I have had a look at the original edition it seems - that link appears to be a newer version, briefly going over the first few pages it seems a lot clearer. I admit the original seemed to jump around quite a bit which made it hard to follow, it would seem to over explain some very basic concepts but then seeming to leap up some of the actual complex parts without much explanation.

I'll have a go at this one.

Cheers,

Rusty

[Merlin66]

AstroartV5 has a photometric module which works very well....
The book you're looking for is
"A practical Guide to Lightcurve Photometry and Analysis" by Brian D Warner, Springer, 2006.
A cooled mono CCD is the recommended weapon of choice.

[AstralTraveller]

Russell,

That sounds like a great endeavor. I can't help with advice but I do have a suggestion. With the gear you will need for exoplanets you could also do asteroid occultation timings. There is really a lot yet to learn about our own solar system and most asteroids have not had their sizes measured directly. This is an area where amateurs can really contribute and where you aren't in 'competition' with professionals. It's likely you will only have a candidate event every week or so, so the rest of the time you can get on with your exoplanet search.

http://www.occultations.org.nz/
http://www.lunar-occultations.com/iota/iotandx.htm

Some software you may want to look at

http://www.lunar-occultations.com/iota/occult4.htm
http://www.occultwatcher.net/

[tonybarry]

Hi Russell,

I would second David's suggestion.

Probably the best reference would be Jacquie's excellent How-To-Do Occs PDF, available here:-

http://www.occultations.org.nz/videotime/manual.htm

Regards,
Tony Barry
WSAAG

[rustigsmed]

thanks for the info Ken appreciated, i'll order that book off fishpond and look into Astroart :thumbsup: I guess there is no avoiding getting a cooled mono.



Thanks David, that doesn't sound too time consuming in terms of observational time, which is of interest. As like everyone i'm time and good weather poor and I also image. I thought that you needed video setup for recording occultation measurements :question:



Thanks Tony - i'll have a look into it - although I think I have skimmed over it in the past.

One equatorial mount just doesn't seem enough these days! I sometimes think I should have purchased two NEQ6's rather than one EQ8 however without a permanent setup it would be a fair juggle.

[DaveO]

Hi Russell

All the above is good advice. I'll also make the following suggestions.

You have set a reasonably high bar to do exoplanet work. Yes, amateurs are definitely making great contributions these days. But if you are new to photometry, then I'd start on something simpler and work up to the exoplanet work.

Start with doing some basic photometry work on variable stars. The suggestion (above) on occulations is also a good starting point. Once you are familiar with the software and equipment, then moving up to something like eclipsing binary stars would be my next suggestion - there are similarities between EB and exoplanet work.

If you want to get involved in photometry, then you should probably spend some quality time on the website of the American Association of Variable Star Observers (www.aavso.org). They have lots of information and tutorials for those new to VSO. They also provide software and tools for members, and any data you submit is also used by other amateurs and lots of professionals, so you get a "feel good" feeling by participating as well.

The books listed above are also good references, and are on my bookshelf too.

In the southern hemisphere, Variable Stars South (www.variablestarssouth.org) focuses on projects covering all sorts of variable stars (visual, DSLR and CCD) and there are projects involved in eclipsing binaries and indeed exoplanets that you can get involved in. I think that's a great organisation, and I learned everything I know from working with them. [full disclosure: I'm VSS's webmaster :D]

There are plenty of people in both of these organisations that can provide assistance and recommendations, so you don't need to do it all by yourself. Your objectives as achievable, and the results are scientifically valid and can be published, so have a look at those sites and hopefully they can help you on the way.

I hope that helps you.

[Blue Skies]

I would recommended video for occultations too, as there are concerns about getting the right time measured when using a CCD device. But it can be done, if you really want it.

However I am very glad to see this thread as I have been contemplating going in a similar direction myself to do photometry of asteroid light curves, so thanks for all the suggestions here everyone.

And I agree about needing an extra mount! I will undoubtedly be looking to invest in a new one in the near-ish future.