Accretion in low-mass members of the Orion Nebula Cluster with young transition disks

¹ Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal
e-mail: Raquel.Albuquerque@astro.up.pt
² Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal
³ Laboratoire Univers et Théories, Observatoire de Paris, Université PSL, CNRS, Université de Paris, 92190 Meudon, France
⁴ Departamento de Física – ICEx-UFMG, Av. Antônio Carlos, 6627, 30270-901 Belo Horizonte, MG, Brazil
⁵ LUPM, Université de Montpellier, UMR 5299 CNRS/IN2P3, cc072, Place Eugène Bataillon, 34090 Montpellier, France
⁶ European Southern Observatory, Alonso de Córdova 3107, Vitacura, Región Metropolitana, Chile

Received: 13 September 2019
Accepted: 24 February 2020

Abstract

Context. Although the Orion Nebula Cluster is one of the most studied clusters in the solar neighborhood, the evolution of the very low-mass members (M_* < 0.25 M_⊙) has not been fully addressed due to their faintness.

Aims. Our goal is to verify if some young and very low-mass objects in the Orion Nebula Cluster show evidence of ongoing accretion using broadband VLT/X-shooter spectra.

Methods. For each target, we determined the corresponding stellar parameters, veiling, observed Balmer jump, and accretion rates. Additionally, we searched for the existence of circumstellar disks through available on-line photometry.

Results. We detected accretion activity in three young stellar objects in the Orion Nebula Cluster, two of them being in the very low-mass range. We also detected the presence of young transition disks with ages between 1 and 3.5 Myr.