Abstract

CCD photometry of the northern open star cluster NGC 7790 has been carried out in BVI photo- metric passbands down to V 21 mag for 1150 stars of which for 700 stars, the data is obtained for the rst time. We derive the most reliable parameters for this cluster using all the available photometric, spectro- scopic and proper motion data. The interstellar extinc- tion over the cluster area is uniform and normal with E(B V )=0 :51 0:03 mag. We determine a distance of 3.3 0.23 Kpc to the cluster. The theoretical isochrone ttings to the Cepheid variables as well as the evolved part of the main-sequence near turn-o point indicate that the cluster is 120 20 Myr old. We estimate the cluster ra- dius to be 3: 0 7 using radial stellar density prole. Both the distance and age determined using period luminos- ity/age relations for the Cepheid variables are consistent with their membership of the cluster. This unique oppor- tunity has therefore been used to rene the zero-point of the period-luminosity relation for the Galactic Cepheids.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.