Transmission spectroscopy using high-resolution spectrographs is quickly becoming a major tool to detect and understand planetary atmospheres, from ultra hot Jupiters to Neptunes-size planets. The CARMENES spectrograph started operations in 2016, and since then we have been using it for the study of planetary atmospheres taking advantage of it simultaneous wavelength coverage from visible to near-infrared (0.5-1.7 micron). This has led to several innovative results, including the first ground-based detections of the He I triplet, allowing the study of exoplanetary tales and scape ratios, or the detection for the first time of the Ca triplet (together with FeII, Na I, and the Balmer series of Hα, Hβ, and Hγ) in the atmosphere of the ultra hot Jupiter (UHJs) MASCARA-2b/KELT20-b. In this talk we will update the several He detections on a sample of about a dozen planets, including various levels of stellar irradiation and planetary masses. I will also discuss CARMENES's capabilities for the characterization of UHJs atmospheres, where our results are consistent with theoretical models, predicting a rich day-side ionosphere.

For the SOC: The CARMENES team as a large sample of exoplanets observed (some published some not yet), which can for the first time provide correlations between stellar irradiation and the detectability of He I triplet and Hα lines, in some cases both, useful for both observers and modelers. I can review the overall results, currently in preparation for a number of publications. For UHJ atmospheres, we can detect several atmospheric species with both trasnmission spectroscopy and cross-correlation techniques simultanoeuly, again for a sample of hot planets. So I think this talk will nicely summaryze several results in two important hot topics of exoplanet atmospheres.