English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We report on the high-resolution spectroscopic observations of two planetarytransits of the hot Jupiter KELT-7b ($M_{\rm p}$ $=$ 1.28 $\pm$ 0.17 M$_{\rmJup}$, $T_{\rm eq}$ $=$ 2028 K) observed with the High Optical ResolutionSpectrograph (HORuS) mounted on the 10.4-m Gran Telescopio Canarias (GTC). Anew set of stellar parameters are obtained for the rapidly rotating parent starfrom the analysis of the spectra. Using the newly derived stellar mass andradius, and the planetary transit data of the Transiting Exoplanet SurveySatellite (TESS) together with the HORuS velocities and the photometric andspectroscopic data available in the literature, we update and improve theephemeris of KELT-7b. Our results indicate that KELT-7 has an angle $\lambda$ =$-$10.55 $\pm$ 0.27 deg between the sky projections of the star's spin axis andthe planet's orbital axis. By combining this angle and our newly derivedstellar rotation period of 1.38 $\pm$ 0.05 d, we obtained a 3D obliquity $\psi$= 12.4 $\pm$ 11.7 deg (or 167.6 deg), thus reinforcing that KELT-7 is awell-aligned planetary system. We search for the presence of H$\alpha$, Li I,Na I, Mg I, and Ca II features in the transmission spectrum of KELT-7b but weare only able to determine upper limits of 0.08-1.4 % on their presence afteraccounting for the contribution of the stellar variability to the extractedplanetary spectrum. We also discuss the impact of stellar variability in theplanetary data. Our results reinforce the importance of monitoring the parentstar when performing high-resolution transmission spectroscopy of the planetaryatmosphere in the presence of stellar activity.

HORuS transmission spectroscopy and revised planetary parameters of KELT-7b