Details

Autor(en) / Beteiligte

• Platais, I
• Melo, C
• Fulbright, J P
• Kozhurina-Platais, V
• Figueira, P
• Barnes, S A
• Mendez, R A

Titel

Trumpler 20 a an old and rich open clusteraaNBa

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2008-12, Vol.391, p.1482-1488

Erscheinungsjahr

2008

Quelle

Wiley-Blackwell Full Collection

Beschreibungen/Notizen

• We show that the open cluster Trumpler 20, contrary to the earlier findings, is actually an old Galactic open cluster. New CCD photometry and high-resolution spectroscopy are used to derive the main parameters of this cluster. At [Fe/H] = -0.11 for a single red giant star, the metallicity is slightly subsolar. The best fit to the colour-magnitude diagrams is achieved using a 1.3-Gyr isochrone with convective overshoot. The cluster appears to have a significant reddening at E(B - V) = 0.46 (for B0 spectral type), although for red giants this high reddening yields the colour temperature exceeding the spectroscopic Teff by about 200 K. Trumpler 20 is a very rich open cluster, containing at least 700 members brighter than MV = +4. It may extend over the field of view available in our study at 20 x 20 arcmin2.