# The outburst and nature of young eruptive low mass stars in dark clouds Source: [The outburst and nature of young eruptive low mass stars in dark clouds]() Collection index: [llms.txt]() Data updated: 2025-10-24T14:09:36.667Z Authors: J. P. Ninan, D. K. Ojha, B. C. Bhatt, K. K. Mallick, A. Tej, D. K. Sahu, S. K. Ghosh, V. Mohan Published: 2012-06-24T17:02:30.000Z ## Abstract The FU Orionis (FUor) or EX Orionis (EXor) phenomenon has attracted increasing attention in recent years and is now accepted as a crucial element in the early evolution of low-mass stars. FUor and EXor eruptions of young stellar objects (YSOs) are caused by strongly enhanced accretion from the surrounding disk. FUors display optical outbursts of $\\sim$ 4 mag or more and last for several decades, whereas EXors show smaller outbursts ($\\Delta$m $\\sim$ 2 - 3 mag) that last from a few months to a few years and may occur repeatedly. Therefore, FUor/EXor eruptions represent a rare but very important phenomenon in early stellar evolution, during which a young low-mass YSO brightens by up to several optical magnitudes. Hence, long-term observations of this class of eruptive variable are important to design theoretical models of low-mass star formation. In this paper, we present recent results from our long-term monitoring observations of three rare types of eruptive young variables with the 2-m Himalayan {\\it Chandra} Telescope (HCT) and the 2-m IUCAA Girawali Observatory (IGO) telescope. ## Recorded benchmark results A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage. ## Original sources and implementation [Original paper]() [PDF]()