Browsing by Author "Barnes, TG"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    BV(RI)C photometry of Cepheids in the Magellanic Cloud
    (1998) Moffett, TJ; Gieren, WP; Barnes, TG; Gomez, M
    We report BT/(RI)(C) data for a select group of 14 Cepheids in the Large Magellanic Cloud and eight in the Small Magellanic Cloud that have preexisting radial velocity curves. The photometry was obtained as part of a program to determine distances to these Cepheids by means of the visual surface brightness technique and to improve significantly the optical BV(RI)(C) light curves of Magellanic Cloud Cepheids. The data were acquired on the 0.9 m telescope at Cerro Tololo Inter-American Observatory with the CFCCD instrument and with the 1 m photometric telescope at ESO using aperture photometry. The median number of measures per Cepheid is 46 in each band, and the uncertainty in the photometry is typically +/-0.01 mag. Using these data together with data from the literature, we determined improved periods for all variables. For most of the Cepheids, these revised periods lead to excellent, low-noise light curves, but for a few variables, the periods are obviously variable.
  • No Thumbnail Available
    Item
    Cepheid variables in the Large Magellanic Cloud cluster NGC 1866.: I.: New BVRI CCD photometry
    (2000) Gieren, WP; Gómez, M; Storm, J; Moffett, TJ; Infante, L; Barnes, TG; Geisler, D; Fouqué, P
    We report BV(RI)(C) CCD photometric data for a group of seven Cepheid variables in the young, rich cluster NGC 1866 in the Large Magellanic Cloud. The photometry was obtained as part of a program to determine accurate distances to these Cepheids by means of the infrared surface brightness technique and to improve the LMC Cepheid database for constructing Cepheid P-L and P-L-C relations. Using the new data together with data from the literature, we have determined improved periods for all variables. For five fundamental mode pulsators, the light curves are now of excellent quality and will lead to accurate distance and radius determinations once complete infrared light curves and radial velocity curves for these variables become available.