Briceno, Cesar

Contact Email: briceno@cida.ve
Institute: Centro de Investigaciones de Astronomia (CIDA)
Apartado Postal 264, Merida 5101-A, Venezuela
First Coauthor: Nuria Calvet
Institute: Anna K. Vivas
Second Coauthor: Lee Hartmann
Research URL:http://www.cida.ve/formacion_estelar.html
Subject Area: Star Formation, Very Young Stars, T-Tauri, H-H Objects
Waveband: Optical
Technique: Photometry
Other: also: Photometric Variability, Spectroscopy
Presentation: Poster Display
Title: A Large Area Variability Survey in Orion OB1: digging into the fossil record of low-mass star formation
Abstract: We present the latest results of our ongoing large scale variability survey of the Orion OB1 Association, carried out with the 8k $\times$ 8k CCD Mosaic Camera on the 1m Schmidt telescope at the Venezuela National Observatory. We extend our initial sample (Briceño et al. 2001 to lower masses ( $\sim 0.15 \> M_{\odot}$). In an area of over 60 square degrees we have unveiled new populations of low-mass young stars over a range of environments, from the dense molecular clouds in Ori OB 1b, to areas devoid of gas in Orion OB 1a. These new young stars span ages from 1-2 Myr in Ori OB 1b to roughly 10 Myr in Ori OB 1a, a likely scenario of sequential star formation triggered by the first generation of massive stars.
Proxy indicators like H$\alpha$ emission and near-IR excesses show that accretion from circumstellar disks in the 10 Myr stars of Ori OB 1a has mostly stopped. This population is a numerous analog of groups like TW Hya, making it an excellent laboratory to look for debris disks and study the epoch of planet formation in sparse, non-clustered environments.