Detecting Exoplanet Atmospheres from 2-m Ground-Based Telescopes
Abstract
The field of exoplanet atmospheric research is quickly expanding. Exoplanet atmospheres are difficult to detect in transmission because their signatures are so small compared to the light coming from the star during transit. However, by comparing observations of the superimposed exoplanet during transit to observations of the star alone, the planet's transmission spectrum may be obtained. We selected the hot Jupiter Kepler-4b and made observations of its host star during primary transits using the long-slit spectrograph at the 2.3m Wyoming Infrared Observatory (WIRO). We used an 1800 l/mm grating which covered a wavelength range from approximately 5400 to 6800 angstroms. The slit was oriented to include a well-known comparison star of similar brightness, located 60 arcseconds away. The spectrum of this comparison star may be used to perform differential spectroscopy with the target spectrum. This minimizes atmospheric variations and helps to normalize the spectrum, reducing it to Poisson noise only. Absorption features seen only during transit can be attributed to the atmosphere of the planet. We will present preliminary data demonstrating the feasibility of detecting exoplanet atmospheres from medium-sized ground-based telescopes.
- Publication:
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American Astronomical Society Meeting Abstracts #221
- Pub Date:
- January 2013
- Bibcode:
- 2013AAS...22134309H