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Petar b

Detecting exoplanet

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Checking one of the 30sec exposures, I get an integrated count of ~70k so assuming the camera gain is set so the well depth of 100k matches 64k counts, this would be ~100k counts which would give ~0.3% 1 sigma uncertainty. (I am assuming you will use an ensemble of comparison stars and that will not significantly contribute to the stochastic uncertainty). Enough signal in principle to see the transit even in the single exposures. 

(The FWHM was ~3 arcsec so perhaps not as good as I might have expected for a good site. The star is K2v so a V filter would be ok.  Plugging these into Richmond's calculator gives a predicted uncertainty of 0.18% )

Edited by robin_astro

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It looks like the conditions were a bit variable so it was either a bit of high cloud or variable seeing.  Nevertheless either the 30s or 60s exposures should be fine (I would recommend the 30s as you can always bin the data).  

Clear can be dependent on your interpretation.  In professional circles you have what is called photometric conditions which is when there are no clouds at all (even high cloud).  Clear is usually referred to as conditions when there is likely to be a bit of high cloud that will impact on photometric calibration of objects.  For the depth of transit you are looking at 'clear' should be fine (by using comparison stars you will remove most of the effect of clouds).

As to whether something needs to be in focus it depends on what you are observing.  In your case you want to be at best focus you can (up to a point and not spending hours doing it).  For very bright stars sometimes people deliberately defocus to stop stars saturating even in very short exposures.  It's no different to having poor seeing and you can just broaden the aperture when you are doing the photometry - the object is that bright you don't need to worry about it.

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I've never used it myself so have no experience personally.  However, the results seem consistent with the other site so it is probably OK.

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Exoplanets sounds exiting. When analyzing the light curve you can use AstroImageJ. I used it when analyzing Kepler data, but not for exoplanets, I looked for variable stars.

You find AstroImageJ here:



And here what I found:



Not bad to use a space telescope !



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