Resumen

CHAVARRIA-K, C.; MORENO-CORRAL, M. A.; TERRANEGRA, L.  y  LARA, E. de. On the PMS Star HBC 498 and its associated nebolous stars¹ (Research note). Rev. mex. astron. astrofis [online]. 2005, vol.41, n.1, pp.77-85. ISSN 0185-1101.

We present recent spectroscopic (resolution ≥ 1750 at λ = 6708 Å) and photometric (ubvy-β) observations of the singular weak-line T Tauri star HBC 498 (= DL Ori/G1) still associated with its parental dust cloud and of at least four other bright neighboring stars associated with reflection nebulosities that together form a tight trapezium in L1641 in Orion. Most of them have the youth signature of Li I in their spectra. We find that two of the objects are "classic" T Tauri and another two are "weak-line" T Tauri stars. From the data and their comparison with models of pre-main sequence stellar evolution we find that they are coeval, and that they have masses of the order of 1 M_๏ and ages of the order of their gravitational contraction times or less (≈1 - 5 x 10⁵ yr). Finally, we briefly discuss their evolutionary state and its repercussions.

Palabras llave : Stars [Abundances]; Stars [Emission line]; Stars [Individual (HBC 498)]; Stars [Pre-main sequence].

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