| 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: | Samrat Ghosh 1,2,
Soumen Mondal 2,
Somnath Dutta 3,
Ramkrishna Das 2,
Santosh Joshi 1,
Sneh Lata 1,
Rajib Kumbhakar 2,
|
| Authors Affiliation: | 1. Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital-263002, India;
2. S N Bose National Centre for Basic Sciences, Salt Lake, Kolkata 700 106, India;
3. Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 10617, Taiwan |
| Mode of Presentation: | 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. |
