SEMINÁRIO DO DEPARTAMENTO DE ASTRONOMIA
Young Stellar Objects in Carina nebula. Near-Infrared variability and spectroscopy
a talk by Jura Borissova (Universidad de Valparaiso, Chile)
Abstract: We present a catalog of 652 young stellar objects (YSOs) in the Carina star-forming region. The catalog was constructed by combining near-infrared Ks-band variability from the VISTA Variables in the Vía Láctea eXtended survey and medium-resolution H-band spectroscopy from APOGEE-2, Sloan Digital Sky Survey IV. Analysis of fundamental stellar parameters reveals typical distributions of YSOs, dominated by low-mass (1–4M⊙), solar-metallicity stars with temperatures between 4000 and 6000 K. Only a small fraction (4%) of the sources are more massive than 4M⊙, suggesting limited ongoing massive star formation in Carina.
Short-Bio: I am full professor in the Universidad de Valparaiso, Chile. My scientific interests are primarily centered on the star formation, stellar variability, the characteristics of young star clusters, and the resolved stellar populations within Milky Way galaxy. Furthermore, I am interested of machine learning, the large-scale surveys, and the astronomical databases.
Optical and NIR photometry of YSO candidates
a talk by Radostin Kurtev (Universidad de Valparaiso, Chile)
Abstract: Using data from the Zwicky Transient Facility (ZTF), the ALeRCE broker has classified hundreds of thousands of objects as potential optically visible Young Stellar Objects (YSOs). However, this sample is significantly contaminated, primarily by Long-Period Variables (LPVs). To confirm the youth of these candidates and refine the sample, we applied photometric and astrometric selection criteria, cross-matching the list with data from the Gaia astrometry mission and the WISE infrared survey. In addition, we used a variety of variability indices, including Q–M metrics, to characterize the photometric behavior of the YSOs. We also performed a photometric characterization of candidate massive YSOs in the Carina Nebula—objects for which APOGEE spectra are available—using the VVVX database. Here, we present the first results of our study.
Short-Bio: Dr. Radostin Kurtev is a Full Professor of Astrophysics at the Instituto de Física y Astronomía, Universidad de Valparaíso, Chile. His research focuses on stellar variability, young stellar objects, stellar clusters and the structure of the Milky Way. He has been a founding member of the VVV and VVVX surveys and collaborates closely with the ALeRCE project on time-domain studies of variable stars. Dr. Kurtev is currently involved in the preparation of the KMOS–VVVX_GalCen survey and in several projects linking ZTF, Gaia and infrared data to characterize young and massive stellar populations in the Galactic disk.