Search results for "Distance modulus"

showing 3 items of 3 documents

CCD uvby-beta photometry of young open clusters. I. The double cluster h and chi Persei

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 Persei nucleus, increasing from west to east, with values ranging from E(b-y)=0.328+-0.022 in the western part to E(b-y)=0.465+-0.025 in the south-east. Towards chi Persei the reddening is fairly constant, with E(b-y)=0.398+-0.025. Both clusters share a common distance modulus of 11.7+-0.1 mag., and an age of log t=7.10+-0.05 years.

PhysicsNGC 869Astrophysics (astro-ph)FOS: Physical sciencesAstronomy and AstrophysicsPhotometric ; Stars ; Early-type ; Galaxy ; NGC 869 ; NGC 884AstrophysicsEarly-typeNGC 884PhotometricUNESCO::ASTRONOMÍA Y ASTROFÍSICAAstrophysicsStars:ASTRONOMÍA Y ASTROFÍSICA::Cosmología y cosmogonia [UNESCO]Photometry (optics)StarsDistance modulusGalaxySpace and Planetary ScienceCluster (physics)UNESCO::ASTRONOMÍA Y ASTROFÍSICA::Cosmología y cosmogonia:ASTRONOMÍA Y ASTROFÍSICA [UNESCO]Open cluster
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CCDuvbyβ photometry of the young open cluster NGC 663

2004

NGC 663 is a young, moderately rich open cluster, known to contain one of the largest fractions of Be stars among all galactic clusters. In this work we present CCD uvby-beta photometry for stars in its central area. We have used these data to obtain the main cluster physical parameters. We find that the reddening is highly variable, with values ranging from E(b-y)=0.639+/-0.032 in the central part to E(b-y)=0.555+/-0.038 in the south-east. The distance modulus is found to be 11.6+/-0.1 mag.(2.1 Kpc), and the age log t=7.4+/-0.1 years (25+7/-5 Myr). The age obtained is consistent with the interpretation of the Be phenomenon as an evolutionary effect.

PhysicsPhotometry (optics)StarsDistance modulusGalaxy groups and clustersSpace and Planetary ScienceAstrophysics (astro-ph)FOS: Physical sciencesAstronomy and AstrophysicsAstrophysicsAstrophysicsOpen clusterMonthly Notices of the Royal Astronomical Society
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Parameter properties and stellar population of the old open cluster NGC 3960

2004

We present a $BVI$ photometric and astrometric catalogue of the open cluster NGC 3960, down to limiting magnitude $V\sim22$, obtained from observations taken with the Wide Field Imager camera at the MPG/ESO 2.2 m Telescope at La Silla. The photometry of all the stars detected in our field of view has been used to estimate a map of the strong differential reddening affecting this area. Our results indicate that, within the region where the cluster dominates, the $E(V-I)$ values range from 0.21 up to 0.78, with $E(V-I)=0.36$ ($E(B-V)=0.29$) at the nominal cluster centroid position; color excesses $E(V-I)$ up to 1 mag have been measured in the external regions of the field of view where field …

PhysicsStellar populationAstrophysics (astro-ph)CentroidFOS: Physical sciencesAstronomy and AstrophysicsAstrophysicsAstrophysicsPower lawPhotometry (optics)StarsDistance modulusSpace and Planetary ScienceLimiting magnitudeOpen cluster
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