EDP Sciences
Free access
Volume 394, Number 2, November I 2002
Page(s) 479 - 488
Section Stellar clusters and associations
DOI http://dx.doi.org/10.1051/0004-6361:20021200

A&A 394, 479-488 (2002)
DOI: 10.1051/0004-6361:20021200

CCD $uvby\beta$ photometry of young open clusters

I. The double cluster h and $\chi$ Persei
G. Capilla1 and J. Fabregat1, 2

1  Observatorio Astronómico, Universidad de Valencia, 46100 Burjassot, Spain
2  GEPI/FRE K2459 du CNRS, Observatoire de Paris-Meudon, 92195 Meudon Principal Cedex, France

(Received 29 March 2002 / Accepted 6 August 2002 )

We present CCD $uvby\beta$ photometry for stars in the nuclei of the young double cluster h and $\chi$ Persei. We find that the reddening is highly variable through the h Per nucleus, increasing from west to east, with values ranging from $E(b-y) = 0.328\pm0.022$ in the western part to $E(b-y) = 0.465\pm0.024$ in the south-east. Towards $\chi$ Per the reddening is fairly constant, with $E(b-y) =
0.398\pm0.025$ . Both clusters share a common distance modulus of $11.7\pm0.1$ mag, and an age of $\log t = 7.10\pm0.05$ years.

Key words: techniques: photometric -- stars: early-type -- Galaxy: open clusters and associations: individual: NGC 869, NGC 884

Offprint request: J. Fabregat, juan@pleione.uv.es

Tables at the CDS

© ESO 2002