New Candidate Eruptive Young Stars in Lynds 1340

TL;DR

This study discovers three candidate eruptive young stars in Lynds 1340, revealing diverse outburst behaviors and suggesting no direct correlation between outburst characteristics and stellar evolution stages.

Contribution

The paper reports the identification of three new candidate eruptive young stars with varied outburst types and provides multi-wavelength observations linking their activity to different evolutionary stages.

Findings

Identified three candidate eruptive young stars with diverse outburst behaviors.

Observed FUor-like spectrum and EXor-type brightening in the candidates.

Found no clear correlation between outburst amplitude/time scale and stellar evolution.

Abstract

We report on the discovery of three candidate eruptive young stars, found during our comprehensive multi-wavelength study of the young stellar population of the dark cloud L1340. These stars are as follows. (1) IRAS 02224+7227 (2MASS 02270555+7241167, HH 487 S) exhibited FUor-like spectrum in our low-resolution optical spectra. The available photometric data restrict its luminosity to 23 L_sun < L_bol < 59 L_sun. (2) 2MASS 02263797+7304575, identified as a classical T Tauri star during our H alpha survey, exhibited an EXor type brightening in 2005 November, at the time of the SDSS observations of the region. (3) 2MASS 02325605+7246055, a low-mass embedded young star, associated with a fan-shaped infrared nebula, underwent an outburst between the DSS1 and DSS2 surveys, leading to the appearance of a faint optical nebula. Our [SII] and H alpha images, as well as the Spitzer IRAC 4.5 micron images revealed Herbig-Haro objects associated with this star. Our results suggest that amplitudes and time scales of outbursts do not necessarily correlate with the evolutionary stage of the stars.