| Title | The secular period behavior of 38 RR Lyrae stars in the LMC globular cluster NGC 2257. |
| Authors | Nemec, J. M.; Hazen-Liller, M. L.; Hesser, J. E. |
| Bibcode | 1985ApJS...57..329N Search ADS ↗ |
| Abstract | The secular period behavior of 38 RR Lyrae stars in the LMC globular cluster NGC 2257 is investigated using new PDS and visual photometry of plates taken during 1951-61 and recent photometry of CTIO plates taken during 1971-82. Accurate periods, light curves, and phases of maximum light are derived for the cluster variables. The period behavior of the stars is derived under the assumption that the periods are either constant or changing uniformly with time. Detailed remarks on all the NGC 2257 variables are made. As a check on the reduction procedures, period change rates are also derived for 15 RR Lyrae stars in four galactic globular clusters and the results are compared with previously derived results. Period change rate distributions and mean period change rates as a function of position in the color-magnitude diagram and RR Lyrae type are derived and compared with galactic globular cluster stars. |
| Objects | 19 Objects Search NED ↙ |
