Hostname: page-component-8448b6f56d-gtxcr Total loading time: 0 Render date: 2024-04-24T23:36:47.290Z Has data issue: false hasContentIssue false

Investigation of the Double-mode Cepheid TU Cas: Atmospheric Parameters and Chemical Composition

Published online by Cambridge University Press:  15 February 2018

S. M. Andrievsky
Affiliation:
Odessa State University, Department of Astronomy, Shevchenko Park, 270014 Odessa, Ukraine
V. V. Kovtyukh
Affiliation:
Odessa State University, Department of Astronomy, Shevchenko Park, 270014 Odessa, Ukraine
E. N. Makarenko
Affiliation:
Odessa State University, Department of Astronomy, Shevchenko Park, 270014 Odessa, Ukraine
I. A. Usenko
Affiliation:
Odessa State University, Department of Astronomy, Shevchenko Park, 270014 Odessa, Ukraine

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Atmospheric parameters and abundances of 25 elements were determined from two spectrograms of TU Cas (with dispersion 9 Å/mm) obtained in 1977 and 1990. We find Teff= 5860 - 6000K; logg = 1.0 - 1.5; and vt = 2.9 - 5.3 km/s.

The value of [Fe/H] ∼ -0.5 testifies to the fact that TU Cas is deficient in metals compared with other double-mode Cepheids. More exact values of [Fe/H] for 9 double-mode Cepheids in the Southern Hemisphere (Barrell 1982), V367 Set (a member of the open cluster NGC 6649) and our value for TU Cas all show a good correlation with P1/P0. As the atmospheric Fe abundance increases, the ratio P1/P0 decreases.

Our measured values for abundances (in brackets) of various elements in the atmosphere of TU Cas are: C (8.26), Na (6.32), Mg (7.07), Si (6.85), S (6.96), Ca (5.88), Sc (2.71), Ti (4.34), V (3.35), Cr (5.29), Mn (4.92), Fe (6.94), Co (4.47), Ni (5.70), Zn (3.63), Sr (2.00), Y (2.17), Zr (2.21), Ba (1.41), La (1.08), Ce (0.96), Nd (0.82), Sm (0.42), Eu (1.04), and Gd (0.92).

Type
Windows on the Instability Strip
Copyright
Copyright © Cambridge University Press 1993

References

Barrell, S.L., 1982, MNRAS, 200, 127 Google Scholar