New Cepheid distances to nearby galaxies based on BVRI CCD photometry. II - The local group galaxy M33

Journal Article · Wed May 01 00:00:00 EDT 1991 · Astrophysical Journal; (United States)

DOI:https://doi.org/10.1086/169991· OSTI ID:5587593

Freedman, W L; Wilson, C D; Madore, B F ^[1]

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1. Observatories of the Carnegie Institution, Pasadena, CA (USA) California Institute of Technology, Pasadena JPL, Pasadena, CA (USA)

A true distance modulus to the nearby spiral galaxy M33 has been determined based on CCD photometry obtained at BVRI wavelengths. M33 is presently one of five nearby galaxies used in the calibration of the IR Tully-Fisher relation, and thereby in the determination of the Hubble constant. Using period-luminosity relations at several wavelengths offers the advantage that the distance moduli derived can be corrected for the effects of interstellar extinction. These data indicate that there is internal reddening affecting the Cepheid photometry in M33 which must be accounted for if a true distance modulus is to be obtained for this galaxy. Adopting a true distance modulus to the LMC of 18.5 mag, the new CCD data yield a true distance to M33 of 24.64 + or {minus} 0.09 mag, corresponding to a linear distance of 840 kpc. A mean value of the total color excess (foreground and internal) for the Cepheids in M33 is estimated to be E(B {minus} V) = 0.10 + or {minus} 0.09 mag, assuming a value for the total mean LMC Cepheid color excess of 0.10 mag. 33 refs.

• OSTI ID: 5587593
• Journal Information: Astrophysical Journal; (United States), Vol. 372; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
GALAXIES
DISTANCE
CALIBRATION
CEPHEIDS
CHARGE-COUPLED DEVICES
COLOR
HUBBLE EFFECT
INTERSTELLAR SPACE
LUMINOSITY
MAGELLANIC CLOUDS
PHOTOMETRY
SPIRAL CONFIGURATION
CONFIGURATION
OPTICAL PROPERTIES
ORGANOLEPTIC PROPERTIES
PHYSICAL PROPERTIES
PULSATING VARIABLE STARS
SEMICONDUCTOR DEVICES
SPACE
STARS
VARIABLE STARS
640105* - Astrophysics & Cosmology- Galaxies