Color excesses of classical cepheids and the structure of our Galaxy

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:5472706

Kim, C

Color excesses of 446 classical cepheids were taken from literature and transformed to a single homogeneous system. On the basis of these color excess data, fundamental data for 401 classical cepheids were compiled and a discussion of Galactic structure based on their space distribution is given. The PC-relation is derived and compared with similar relations for the Magellanic Clouds. Major spiral arms were traced from the distribution of long-period cepheids on the projected Galactic plane and the position of these spiral features are compared with those from other optical tracers such as HII regions and OB star groups. The z-coordinate distribution of cepheids confirms the finding of Fernie (1968b) that the cepheid layer is inclined toward a formal Galactic plane and the sun is located above the cepheid plane. It was found that the z-distribution fits better the parabolic form than a barometric form and a scale height of 54 pc was found. The correlation between the distribution of cepheids and the dust complexes within 2 kpc from the sun is investigated. The well known phenomenon that the periods of classical cepheids decrease away from the Galactic center was crudely interpreted as due to an age gradient rather than an abundance gradient under the assumption that relations between the period and Galactocentric distance and between the abundance and period are linear.

• Research Organization: Brigham Young Univ., Provo, UT (USA)
• OSTI ID: 5472706
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
640105 -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CEPHEIDS
COLOR
DISTRIBUTION
GALAXIES
MILKY WAY
OPTICAL PROPERTIES
ORGANOLEPTIC PROPERTIES
PHYSICAL PROPERTIES
PULSATING VARIABLE STARS
STARS
VARIABLE STARS