SCYON Abstract

Received on November 25 2005

NGC 2401: A template of the Norma-Cygnus Arm's young population in the
Third Galactic Quadrant

AuthorsG. Baume(1), A. Moitinho(2), R. Vazquez (1), G. Solivella(1), G. Carraro(3), S. Villanova(4)
(1) La Plata
(2) Lisboa
(3) UChile/Yale
(4) Padova
Accepted byMonthly Notices of the Royal Astronomical Society
Links NGC 2401


Based on a deep optical CCD (UBV(RI)c) photometric survey and on the Two -Micron All-Sky-Survey (2MASS) data we derived the main parameters of the open cluster NGC 2401. We found this cluster is placed at 6.3 ± 0.5 kpc (V0 - MV = 14.0 ± 0.2) from the Sun and is 25 Myr old, what allows us to identify NGC 2401 as a member of the young population belongin g to the innermost side of the extension of the Norma-Cygnus spiral-arm in t he Third Galactic Quadrant. A spectroscopic study of the emission star LSS 440 that lies in the cluster area revealed it is a B0Ve star; however, we could not confirm it is a cluster member. We also constructed the cluste r luminosity function (LF) down to V ~ 22 and the cluster initial mass function (IMF) for all stars with masses above M ~ 1-2 M(sun). It wa s found that the slope of the cluster IMF is x ~ 1.8 ± 0.2. The presence of a probable PMS star population associated to the cluster is weakly revealed.