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rodluger / planetplanet

A general photodynamical code for exoplanet light curves
https://rodluger.github.io/planetplanet
GNU General Public License v3.0
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OST ppm noise floor #30

Closed rodluger closed 7 years ago

rodluger commented 7 years ago

I want to tie in our OST discussion with Figure 14. I argue that if orbital parameters are well known, distinguishing between an airless and a thick atmosphere c requires the sensitivity to a ~80 ppm signal. If the orbital parameters are unconstrained, the signal we're looking for is the asymmetry of the light curve, which is ~10 ppm. Jake, can you calculate what the sensitivity of OST is at 50 microns? I imagine this is just the size of the error bars in ppm, right? That would be the "noise floor" for a 1-sigma detection. We should then calculate how many exposures we would need to stack to get down to 10 ppm. Can you do this?

jlustigy commented 7 years ago

For a 5 min cadence with our OST setup, I find that 11 stacked observations reaches 10 ppm precision on the lightcurve.

[image: Inline image 1]

On Thu, Jul 13, 2017 at 9:38 AM, Rodrigo Luger notifications@github.com wrote:

Assigned #30 https://github.com/rodluger/planetplanet/issues/30 to @jlustigy https://github.com/jlustigy.

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/rodluger/planetplanet/issues/30#event-1162927649, or mute the thread https://github.com/notifications/unsubscribe-auth/AIeJIhkk3k9tqCPhBgzV9obyLlRWOSeSks5sNkf2gaJpZM4OXQFH .

-- Jacob Lustig-Yaeger Astronomy & Astrobiology Graduate Student University of Washington jlustigy.github.io

jlustigy commented 7 years ago

Bad news: I had a bug in my custom filters where I was extrapolating them far beyond their specified boundaries. So now we would have to observe ~500 (!) events to reach 10 ppm precision. Sorry about that!

But I also made a figure of SNR on an occultation of c by b as a function of wavelength from ~10-80 microns, which shows a rise up to ~15-20 microns as the contrast increases, then a decline beyond that as there are fewer and fewer photons to detect. [image: Inline image 1]

On Fri, Jul 14, 2017 at 3:15 PM, Jacob Lustig-Yaeger jlustigy@uw.edu wrote:

For a 5 min cadence with our OST setup, I find that 11 stacked observations reaches 10 ppm precision on the lightcurve.

[image: Inline image 1]

On Thu, Jul 13, 2017 at 9:38 AM, Rodrigo Luger notifications@github.com wrote:

Assigned #30 https://github.com/rodluger/planetplanet/issues/30 to @jlustigy https://github.com/jlustigy.

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/rodluger/planetplanet/issues/30#event-1162927649, or mute the thread https://github.com/notifications/unsubscribe-auth/AIeJIhkk3k9tqCPhBgzV9obyLlRWOSeSks5sNkf2gaJpZM4OXQFH .

-- Jacob Lustig-Yaeger Astronomy & Astrobiology Graduate Student University of Washington jlustigy.github.io

-- Jacob Lustig-Yaeger Astronomy & Astrobiology Graduate Student University of Washington jlustigy.github.io