Photometry of Praesepe in BVRI colors

Journal Article · Mon Oct 01 04:00:00 EDT 1979 · Astron. J.; (United States)

DOI:https://doi.org/10.1086/112580· OSTI ID:5790367

Upgren, A R; Weis, E W; DeLuca, E E

Photoelectric photometry in BVRI colors has been obtained for 55 stars in the region of the Praesepe cluster. The stars to be observed were chosen from the proper motion studies of Klein Wassink and Hertzsprung. Their colors cover the range between 0.75 and 1.50 in B-V and between 0.25 and 0.85 in R-I and are thus mostly K and early M members of the lower main sequence. Five of the stars appear to be nonmembers on the basis of their positions in V,B-V and V,R-I diagrams, and several others appear to be binary star members. The rest of the stars define a sequence similar in slope to that of the Hyades and lying 3.0 mag below it. The modulus is thus 6.20 +- 0.05 mag and the distance is 174 +- 4 pc. The presently widely quoted modulus of 6.0 mag based on UBV and uvby..beta.. photometry of brighter stars was based on a modulus of 3.0 mag for the Hyades. The recent correction of +0.2 mag for the Hyades modulus raises the earlier determinations into close agreement with that of 6.2 mag found here.

• Research Organization: Van Vleck Observatory, Wesleyan University, Middletown, Connecticut 06457
• OSTI ID: 5790367
• Journal Information: Astron. J.; (United States), Journal Name: Astron. J.; (United States) Vol. 84:10; ISSN ANJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BINARY STARS
MAIN SEQUENCE STARS
MOTION
PHOTOMETRY
PROPER MOTION
STAR CLUSTERS
STARS