RR Lyrae stars in local group galaxies. II. NGC 147

Journal Article · Sun Jul 01 00:00:00 EDT 1990 · Astronomical Journal; (USA)

DOI:https://doi.org/10.1086/115495· OSTI ID:6593721

Saha, A; Hoessel, J G; Mossman, A E ^[1]

---

1. Mount Wilson and Las Campanas Observatories, Pasadena, CA (USA) Space Telescope Science Institute, Baltimore, MD (USA) Washburn Observatory, Madison, WI (USA)

Deep CCD images of NGC 147 taken with the 4-shooter on the Hale 5 m telescope have been processed to find and photometrically measure RR Lyrae stars. 36 variable stars have been found, of which 32 are surmised to be RR Lyrae stars. Finding charts, periods, and light curves are presented. The mean magnitude of the RR Lyraes is determined to be 25.25 mag. A distance modulus 23.92 is derived, based on the best currently available values of foreground extinction and mean absolute magnitudes of RR Lyrae stars. A wide range of periods is seen for the RR Lyrae stars, indicating a correspondingly wide range of metallicities for the stars in NGC 147. The distance modulus derived here places NGC 147 at a distance of 154 kpc from the center of M31, and in conjunction with the line sight velocities of these two galaxies, this implies a lower limit of 7.2 x 10 to the 11th solar masses for the mass of M31. 23 refs.

• OSTI ID: 6593721
• Journal Information: Astronomical Journal; (USA), Vol. 100; ISSN 0004-6256
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
GALAXIES
DISTANCE
VARIABLE STARS
PHOTOMETRY
BRIGHTNESS
CHARGE-COUPLED DEVICES
CHEMICAL COMPOSITION
DETECTION
IDENTIFICATION SYSTEMS
MASS
POPULATIONS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SEMICONDUCTOR DEVICES
STARS
640105* - Astrophysics & Cosmology- Galaxies
640102 - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources