Detection Limits of Exoplanetary Atmospheres With 2-m Class Telescopes

The expected atmospheric signal for well-characterised transiting planets as a function of the visual magnitude of the host star. The orange triangle shows the position of HD 189733, while the red triangle is the rescaled value, assuming a 2mclass telescope (see text). All the points above the solid line are suitable candidates to perform transmission spectroscopy with a 2m-class telescope.

Transmission spectroscopy is an important technique to probe the atmospheres of exoplanets.

With the advent of TESS and, in the future, of PLATO, more and more transiting planets around bright stars will be found and the observing time at large telescopes currently used to apply these techniques will not suffice. We demonstrate here that 2-m class telescopes equipped with spectrographs with high resolving power may be used for a certain number of potential targets. We obtained a time series of high-resolution FEROS spectra at the 2.2-m telescope at La Silla of the very hot Jupiter hosting planet WASP-18b and show that our upper limit is consistent with the expectations.

This is the first analysis of its kind using 2-m class telescopes, and serves to highlight their potential. In this context, we then proceed to discuss the suitability of this class of telescopes for the upcoming flood of scientifically interesting targets from TESS space mission, and propose a methodology to select the most promising targets. This is of particular significance given that observing time on 2-m class telescopes is more readily available than on large 8-m class facilities.

P. Kabath, J. Zak, H. M.J. Boffin, V. D. Ivanov, D. Jones, M. Skarka
(Submitted on 12 May 2019)

Comments: accepted PASP
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1905.04665 [astro-ph.EP] (or arXiv:1905.04665v1 [astro-ph.EP] for this version)
Submission history
From: Petr Kabath
[v1] Sun, 12 May 2019 08:14:44 UTC (513 KB)

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