WINERED: A Near-Infrared High-Resolution Spectrograph in Regular Operation at Magellan Clay, LCO

WINERED is a PI-instrument now in regular operation on the Magellan Clay telescope at Las Campanas Observatory. It is a near-infrared high-resolution spectrograph covering the Y and J bands (0.9–1.35 µm), offering resolving powers of R ≈ 28,000 and 70,000. Thanks to its exceptionally high efficiency (∼50%), WINERED is currently the most sensitive high-resolution spectrograph in the YJ bands. This capability enables precise elemental abundance measurements of relatively faint stars, such as those in the Magellanic Clouds, and opens new opportunities in exoplanet transmission spectroscopy. In this talk, after the general introduction to the WINERED’s operation and performance at Magellan Clay, I’d like to highlight results and plans for one of my main scientific targets, the chemical abundances of Cepheid variables across different stellar populations. I will also present new analysis tools under development, including a PCA-based telluric correction pipeline.