Details

Autor(en) / Beteiligte

• Burton, J. R.
• Watson, C. A.
• Rodríguez-Gil, P.
• Skillen, I.
• Littlefair, S. P.
• Dhillon, S.
• Pollacco, D.

Titel

Defocused transmission spectroscopy: a potential detection of sodium in the atmosphere of WASP-12b

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2015-01, Vol.446 (1), p.1071-1082

Ort / Verlag

London: Oxford University Press

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We report on a pilot study of a novel observing technique, defocused transmission spectroscopy, and its application to the study of exoplanet atmospheres using ground-based platforms. Similar to defocused photometry, defocused transmission spectroscopy has an added advantage over normal spectroscopy in that it reduces systematic errors due to flat-fielding, point spread function variations, slit-jaw imperfections and other effects associated with ground-based observations. For one of the planetary systems studied, WASP-12b, we report a tentative detection of additional Na absorption of 0.12 ± 0.03[+0.03] per cent during transit using a 2 Å wavelength mask. After consideration of a systematic that occurs mid-transit, it is likely that the true depth is actually closer to 0.15 per cent. This is a similar level of absorption reported in the atmosphere of HD 209458b (0.135 ± 0.017 per cent; Snellen et al. 2008). Finally, we outline methods that will improve the technique during future observations, based on our findings from this pilot study.