The metallicity of Palomar 1

Rosenberg, A.; Piotto, G.; Saviane, I.; Aparicio, A.; Gratton, R.
Referencia bibliográfica

Astronomical Journal, vol. 115, p. 658

Fecha de publicación:
2
1998
Número de autores
5
Número de autores del IAC
1
Número de citas
20
Número de citas referidas
15
Descripción
Palomar 1 is a peculiar Galactic globular cluster suspected of being younger than the bulk of Galactic halo objects. However, such a low age can be confirmed only after a reliable determination of the metallicity. In the present paper, we use the equivalent widths, W, of the Ca II triplet on medium-resolution spectra to determine the metal content of Pal 1. From the comparison of the luminosity-corrected W's in four stars of Pal 1 with those of a sample of stars in each of three calibration clusters, we derive (Fe/H) = -0.6 +/- 0.2 on the Zinn-West scale or (Fe/H) = -0.7 +/- 0.2 on the Carretta-Gratton scale. We also obtain a radial velocity v(r) = -82.8 +/- 3.3 km/s for Pal 1.