Abstract Details
| Name: SAMRAT GHOSH Affiliation: Aryabhatta Research Institute of Observational Sciences: ARIES Conference ID: ASI2025_744 Title : Dynamic Photometric Variability in Three Young Brown Dwarfs in Taurus: Detection of Optical Flares with TESS data Authors and Co-Authors : Samrat Ghosh 1,2, Soumen Mondal 2, Somnath Dutta 3, Ramkrishna Das 2, Santosh Joshi 1, Sneh Lata 1, Rajib Kumbhakar 2, Abstract Type : Poster Abstract Category : Stars, Interstellar Medium, and Astrochemistry in Milky Way Abstract : We present I-band time-series photometric variability studies of three known nearby (∼ 140 pc) and young ( ∼1 Myr) brown dwarfs (BD) in the Taurus star-forming region in the Perseus Molecular Cloud. From 10 nights of ground-based observations over a time span of 10 years, with a typical run of 3 to 6 hours each night, we estimated that the BDs show unstable short-scale periodicity from 1.5 to 4.8 hours. Using the long-term photometry from the Transiting Exoplanet Survey Satellite (TESS), we have conducted a time-resolved variability analysis of CFHT-BD-Tau 2 and CFHT-BD-Tau 4, revealing orbital periods of ∼ 0.96 days and ∼ 3 days respectively, consistent with earlier studies. We also found two superflares in TESS data for CFHT-BD-Tau 4 and estimated the flare energies in the 10^35 - 10^36 erg range. A magnetic field of ∼ 1.66 kG is required to generate such flare energies on this BD. We performed spot modelling analysis on CFHT-BD-Tau 2 and CFHT-BD-Tau 4 to address the variability detected in the data using the package BASSMAN. The sources ' spectral energy distribution and infrared colours suggest sufficient circumstellar material around them. |