The radii of long-period Cepheids

Journal Article · Thu Jun 01 04:00:00 EDT 1989 · Publications of the Astronomical Society of the Pacific; (USA)

DOI:https://doi.org/10.1086/132473· OSTI ID:5595387

Coker, R; Madore, B; Mould, J; Oke, J B; Picard, A ^[1]

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1. Palomar Observatory, Pasadena, CA (USA)

During the 1986/7 observing year, the radial-velocity and spectral energy distributions of a number of Cepheid variables with periods of 10 days or longer were monitored. The data are used following the Baade Wesselink formalism to estimate the radii of Cepheids and their luminosities. It is concluded that the precision of the velocities presented here is such that the dominant source of error is now the data on temperature variation. With the present data, the mean radius of VX Per is 78 + or - 28 solar radii and the mean radius of SZ Cas is 38 + or - 6 solar radii. A precision of 15 K in measuring temperatures is required to reduce this error to 10 percent. This is beyond the limits of the type of spectrophotometry presented here, but may be within the capabilities of optical/IR (V-K) photometry. 23 refs.

• OSTI ID: 5595387
• Journal Information: Publications of the Astronomical Society of the Pacific; (USA), Journal Name: Publications of the Astronomical Society of the Pacific; (USA) Vol. 101; ISSN PASPA; ISSN 0004-6280
• 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
CEPHEIDS
ENERGY SPECTRA
ERRORS
LUMINOSITY
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PULSATING VARIABLE STARS
RADIAL VELOCITY
SIZE
SPECTRA
SPECTROPHOTOMETRY
STARS
TABLES
TEMPERATURE MEASUREMENT
VARIABLE STARS
VARIATIONS
VELOCITY