ULTRACAM z′-band detection of the secondary eclipse of WASP-12b

Föhring, D.; Dhillon, V.S.; Madhusudhan, N.; Marsh, T.R.; Copperwheat, C.M.; Littlefair, S.P.; Wilson, R.W.

Abstract

We present z′-band secondary eclipse photometry of the highly irradiated hot Jupiter WASP-12b using ULTRACAM on the 4.2 m William Herschel Telescope. We measure a decrease in flux of δ = 0.130 ± 0.013 per cent during the passage of the planet behind the star, which is significantly deeper than the previous measurement at this wavelength (0.082 ± 0.015 per cent). Our secondary eclipse is best fitted with a mid-eclipse phase, ϕ, that is compatible with a circular orbit ϕ = 0.501 ± 0.002, in agreement with previous results. In combination with existing data, our eclipse depth measurement allows us to constrain the characteristics of the planet's atmosphere, which is consistent with a carbon-rich model, with no evidence for a strong thermal inversion. If the difference in eclipse depth reported here compared to that of López-Morales et al. is of physical origin, as opposed to due to systematics, it may be caused by temporal variability in the flux, due to atmospheric dynamics.

Citation

Föhring, D., Dhillon, V., Madhusudhan, N., Marsh, T., Copperwheat, C., Littlefair, S., & Wilson, R. (2013). ULTRACAM z′-band detection of the secondary eclipse of WASP-12b. Monthly Notices of the Royal Astronomical Society, 435(3), 2268-2273. https://doi.org/10.1093/mnras/stt1443

• Journal Article Type: Article
• Acceptance Date: Aug 1, 2013
• Publication Date: Nov 1, 2013
• Deposit Date: Oct 15, 2015
• Publicly Available Date: Oct 22, 2015
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 435
• Issue: 3
• Pages: 2268-2273
• DOI: https://doi.org/10.1093/mnras/stt1443
• Keywords: Techniques: photometric, Stars: individual: WASP-12, Planetary systems.
• Public URL: https://durham-repository.worktribe.com/output/1397563