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Here we present high cadence photometry taken by the Acquisition Camera on Gemini South, of a close passage by the $sim540$ km radius Kuiper Belt Object, (50000) Quaoar, of a r=20.2 background star. Observations before and after the event show that the apparent impact parameter of the event was $0.019pm0.004$, corresponding to a close approach of $580pm120$ km to the centre of Quaoar. No signatures of occultation by either Quaoars limb or its potential atmosphere are detectable in the relative photometry of Quaoar and the target star, which were unresolved during closest approach. From this photometry we are able to put constraints on any potential atmosphere Quaoar might have. Using a Markov chain Monte Carlo and likelihood approach, we place pressure upper limits on sublimation supported, isothermal atmospheres of pure N$_2$, CO, and CH$_4$. For N$_2$ and CO, the upper limit surface pressures are 1 and 0.7 $mu{bar}$ respectively. The surface temperature required for such low sublimation pressures is $sim33$ K, much lower than Quaoars mean temperature of $sim44$ K measured by others. We conclude that Quaoar cannot have an isothermal N$_2$ or CO atmosphere. We cannot eliminate the possibility of a CH$_4$ atmosphere, but place upper surface pressure and mean temperature limits of $sim138$ nbar and $sim44$ K respectively.
We have searched for the presence of simple P and S-bearing molecules in Titans atmosphere, by looking for the characteristic signatures of phosphine and hydrogen sulfide in infrared spectra obtained by Cassini CIRS. As a result we have placed the fi
We report the detection of an atmosphere on a rocky exoplanet, GJ 1132 b, which is similar to Earth in terms of size and density. The atmospheric transmission spectrum was detected using Hubble WFC3 measurements and shows spectral signatures of aeros
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