Abstract
view Abstract Citations (3) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Kinematical Analysis of the Cepheid Variables. Takase, Bunshiro Abstract The selected 130 Cepheid K term K (km/sec) Sun's distance R0 (kpc) Zero-point correction ~M (mag.) Angular rotational ~ (R0) (km/sec kpc) velocity and its 1st w'(R0) (km/sec kpc2) and 2nd derivatives w" (R1) (km/sec kpc3) Oort's constant A (km/sec kpc) Solar motion S (km/sec) Apex in galactic L"0 (deg) coordinates B011 (deg) variables which have accurate photometric data and also the radial velocity and/or proper motion data were used to determine a consistent set of values concerning the galactic distance scale, the galactic rotation, and the local stellar motion. We solve the equations which express the relations between the observed motion, the solar motion, the differential galactic rotation, the peculiar motion, and other systematic motions, under the condition that the expectation of the peculiar motions is zero. Distances of the Cepheids were calculated using the period-luminosity relation and the period-color relation recently established by Kraft (Kraft, R. P., Astrophys. J. 134, 616, 1961). Thus we obtain the solar motion, the differential galactic rotation, the K term, and so on. We tried two kinds of solutions, one of which includes K term and the other of which does not. Calculations were also made for several R0 values, the distance of the sun from the galactic center, and for cases where the various zero-point corrections, AM, to the Kraft's period-luminosity relation were applied. The table shows results for cases selected from many others because of the reason that they give the A R0 values, where A is the Oort constant, closest to 156 km/sec determined by Schmidt (Schmidt, M., Bull. Astron. Inst. Neth. 13,15,1956) from the 21-cm radio observation. Since the photometric data of the Cepheids have been more accurately determined than their velocity data, it seems better to adopt the cases where no zero-point corrections were applied. Publication: The Astronomical Journal Pub Date: March 1963 DOI: 10.1086/108919 Bibcode: 1963AJ.....68...80T full text sources ADS |
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