The secondary transit of the hot Jupiter WASP-121b at 2 $\mu$m

Abstract

Ground-based observations of the secondary transit in the 2MASS K band are presented for the hot Jupiter WASP-121b. These are the first occultation observations of an extrasolar planet carried out with an instrument attached to a 1m-class telescope (SMARTS' 1.3 m). We find a highly significant transit depth of (0.228 +/- 0.023)%. Together with the Hubble Space Telescope near infrared emission spectrum, current data support more involved atmosphere models with species producing emission/absorption features, rather than simple smooth black body emission. Analysis of the time difference between the primary and secondary transits and the durations of these events yield an eccentricity of e=0.0207 +/- 0.0153, which is consistent with the earlier estimates of low/zero eccentricity, but with a smaller error. Together with the existing K-band data on other systems, WASP-121b lends further support to the lack of efficient heat transport between the day and night sides for nearly all Hot Jupiters.

Size:0.3 MB; Status: After the 1st referee report, re-submitted to A&A

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Cited by in corpus (11)

• Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) IV. A spectral inventory of atoms and molecules in the high-resolution transmission spectrum of WASP-121 b
• Atmospheric Rossiter-McLaughlin effect and transmission spectroscopy of WASP-121b with ESPRESSO
• An emission spectrum for WASP-121b measured across the 0.8-1.1 micron wavelength range using the Hubble Space Telescope
• Confirmation of water emission in the dayside spectrum of the ultrahot Jupiter WASP-121b
• High-resolution atmospheric retrievals of WASP-121b transmission spectroscopy with ESPRESSO: Consistent relative abundance constraints across multiple epochs and instruments
• Emergent Spectral Fluxes of Hot Jupiters: an Abrupt Rise in Day Side Brightness Temperature Under Strong Irradiation
• Spitzer thermal phase curve of WASP-121 b
• The Wanderer: Charting WASP-77A b's Formation and Migration Using a System-Wide Inventory of Carbon and Oxygen Abundances
• Transit-period search from single-event space-based data: the role of wide-field surveys
• Near infrared and optical emission of WASP-5 b
• Secondary eclipses of two brown dwarfs in the K2 fields: detection by multiple dataset merging