* Astronomy

Title: The curious case of PDS 11: a nearby, >10 Myr old, classical T Tauri binary system
Author: Blesson Mathew (1), P. Manoj (1), B. C. Bhatt (2), D. K. Sahu (2), G. Maheswar (3), S. Muneer (2) ((1) Tata Institute of Fundamental Research, (2) Indian Institute of Astrophysics, (3) Aryabhatta Research Institute of Observational Sciences)

We present results of our study of PDS 11 binary system, which belongs to a rare class of isolated, high galactic latitude T Tauri stars. Our spectroscopic analysis reveals that PDS 11 is a M2-M2 binary system with both components showing similar H-alpha emission strength. Both the components appear to be accreting, and are classical T Tauri stars. The lithium doublet Li I 6708 Angstrom, a signature of youth, is present in the spectrum of PDS 11A, but not in PDS 11B. From the application of lithium depletion boundary age-dating method and a comparison with the Li I 6708 equivalent width distribution of moving groups, we estimated an age of 10-15 Myr for PDS 11A. Comparison with pre-main sequence evolutionary models indicates that PDS 11A is a 0.4 solar mass T Tauri star at a distance of 114-131 pc. PDS 11 system does not appear to be associated with any known star forming regions or moving groups. PDS 11 is a new addition, after TWA 30 and LDS 5606, to the interesting class of old, dusty, wide binary classical T Tauri systems in which both components are actively accreting.

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