Issue |
Astron. Astrophys. Suppl. Ser.
Volume 136, Number 2, April II 1999
|
|
---|---|---|
Page(s) | 363 - 372 | |
DOI | https://doi.org/10.1051/aas:1999219 | |
Published online | 15 April 1999 |
The nature of the star clusters ESO 93-SC08 and ESO 452-SC11 *
1
Universidade Federal do Rio Grande do Sul, Dept. de Astronomia, CP 15051, Porto Alegre 91500-970, Brazil
2
Università di Padova, Dept. di Astronomia, Vicolo dell'Osservatorio 5, I-35122 Padova, Italy
3
Universidade de São Paulo, CP 3386, São Paulo 01060-970, Brazil
Received:
13
November
1998
Accepted:
February
1999
We present V and I colour-magnitude diagrams of the
star clusters ESO 93-SC08 and ESO 452-SC11. Both clusters are poorly
populated, and the colour-magnitude diagrams show that ESO 93-SC08
is an intermediate age open cluster, while ESO 452-SC11 is confirmed
as a globular cluster.
The magnitude difference between the turnoff and the clump/horizontal
branch indicates an age of Gyr for ESO 93–SC08, while
ESO 452–SC11 has an age comparable to the average of the halo
globular clusters.
ESO 93–SC08 has a reddening of
= 0.64 and is
located at
kpc
from the Sun. It is a distant open cluster in the outer disk.
ESO 452–SC11 appears to be a southern counterpart of the Palomar clusters.
We derive a reddening of
,
a distance
kpc and a
metallicity
Fe/H
≈
-1.5 for ESO 452–SC08.
The deep CMD shows evidence of depletion at the lower main sequence,
similarly to other poorly populated globular clusters.
Key words: globular clusters: ESO 452–SC11, open clusters: ESO 93–SC08 / HR diagram
© European Southern Observatory (ESO), 1999