Astronomy and Astrophysics, volume 632A, 69-69 (2019/12-0)
Ionized calcium in the atmospheres of two ultra-hot exoplanets WASP-33b and KELT-9b.
YAN F., CASASAYAS-BARRIS N., MOLAVERDIKHANI K., ALONSO-FLORIANO F.J., REINERS A., PALLE E., HENNING T., MOLLIERE P., CHEN G., NORTMANN L., SNELLEN I.A.G., RIBAS I., QUIRRENBACH A., CABALLERO J.A., AMADO P.J., AZZARO M., BAUER F.F., CORTES CONTRERAS M., CZESLA S., KHALAFINEJAD S., LARA L.M., LOPEZ-PUERTAS M., MONTES D., NAGEL E., OSHAGH M., SANCHEZ-LOPEZ A., STANGRET M. and ZECHMEISTER M.
Abstract (from CDS):
Ultra-hot Jupiters are emerging as a new class of exoplanets. Studying their chemical compositions and temperature structures will improve our understanding of their mass loss rate as well as their formation and evolution. We present the detection of ionized calcium in the two hottest giant exoplanets - KELT-9b and WASP-33b. By using transit datasets from CARMENES and HARPS-N observations, we achieved high-confidence-level detections of CaII using the cross-correlation method. We further obtain the transmission spectra around the individual lines of the CaII H&K doublet and the near-infrared triplet, and measure their line profiles. The CaII H&K lines have an average line depth of 2.02±0.17% (effective radius of 1.56Rp) for WASP-33b and an average line depth of 0.78±0.04% (effective radius of 1.47Rp) for KELT-9b, which indicates that the absorptions are from very high upper-atmosphere layers close to the planetary Roche lobes. The observed CaII lines are significantly deeper than the predicted values from the hydrostatic models. Such a discrepancy is probably a result of hydrodynamic outflow that transports a significant amount of CaII into the upper atmosphere. The prominent CaII detection with the lack of significant CaI detection implies that calcium is mostly ionized in the upper atmospheres of the two planets.
© ESO 2019
planets and satellites: atmospheres - techniques: spectroscopic - planets and satellites: individual: WASP-33b - planets and satellites: individual: KELT-9b
VizieR on-line data:
<Available at CDS (J/A+A/632/A69): f6w33hk.dat f6w33irt.dat f7k9hk.dat f7k9irt.dat f8w33hk.dat f8w33irt.dat f8k9hk.dat f8k9irt.dat>
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