Astron. Astrophys. Suppl. Ser. 144, 451-456

Spectroscopy and $BVI_{\rm C}$ photometry of the young open cluster NGC 6604

R. Barbon¹ - G. Carraro¹ - U. Munari² - T. Zwitter³ - L. Tomasella²

Send offprint request: R. Barbon,
e-mail: barbon@pd.astro.it

1 - Osservatorio Astrofisico del Dipartimento di Astronomia, Università di Padova, I-36012 Asiago (VI), Italy
2 - Osservatorio Astronomico di Padova, Sede di Asiago, I-36012 Asiago (VI), Italy
3 - University of Ljubljana, Department of Physics, Jadranska 19, 1000 Ljubljana, Slovenia

Received November 16, 1999; accepted March 21, 2000

Abstract:

$BVI_{\rm C}$ photometry and classification spectroscopy is presented for the young open cluster NGC 6604. Additional Echelle spectroscopy of the brightest members is used to check the reddening against the interstellar NaI and KI absorption lines, to measure the cluster radial velocity and to derive the individual rotational velocities. We obtain 1.7 kpc as the cluster distance, an age of $\sim 5~10^{6}$ years and a reddening E_B-V= 1.02 ($\pm 0.01$ from three independent methods). Pre-ZAMS objects are apparently not detected over the $\bigtriangleup m$ = 8.5 mag explored range. The cluster radial velocity is in agreement with the Hron (1987) model for the Galaxy disk rotation.

Key words: open clusters: general -- open clusters: individual (NGC 6604)