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Properties of Bright Variable Stars in Unusual Metal Rich Cluster NGC 6388
Cardona Velasquez, Gustavo Adolfo

2011, Master of Science (MS), Bowling Green State University, Physics.
We have searched for Long Period Variable (LPV) stars in the metal-rich cluster NGC 6388 using time series photometry in the V and I bandpasses. A CMD was created, which displays the tilted red HB at V = 17.5 mag. and the unusual prominent blue HB at V = 17 to 18 mag. Time-series photometry and periods have been presented for 63 variable stars, of which 30 are newly discovered variables. Of the known variables nine are LPVs. We are the first to present light curves for these stars and to classify their variability types. We find 3 LPVs as Mira, 6 as Semi-regulars (SR) and 1 as Irregular (Irr.), 18 are RR Lyrae, of which we present complementary time series and period for 14 of these stars, and 7 are Population
II Cepheids, of which we present complementary time series and period for 4 of them. The newly discovered variables are all suspected LPV stars and we classified them, using time series photometry and periods, as Mira for 1 star, SR for 15 stars, Irr for 7 stars, Suspected Variables for 7 stars, out of which there are 3 very bright stars that could have overexposed the CCD, with no definite borderline between the SR and Irr stars. Once classified we
used probable distance for the cluster center and location on the CMD to establish possible membership, which left us with 63 possible cluster members, but the crowdedness of the cluster and the fact that the cluster is located near the bulge of the Milky Way prevents us from establishing a better certainty for its membership.
Andrew C. Layden, Dr. (Advisor)
John Laird, Dr. (Committee Member)
Dale W. Smith, Dr. (Committee Member)
171 p.

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Cardona Velasquez, G. (2011). Properties of Bright Variable Stars in Unusual Metal Rich Cluster NGC 6388. (Electronic Thesis or Dissertation). Retrieved from https://etd.ohiolink.edu/

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Cardona Velasquez, Gustavo. "Properties of Bright Variable Stars in Unusual Metal Rich Cluster NGC 6388." Electronic Thesis or Dissertation. Bowling Green State University, 2011. OhioLINK Electronic Theses and Dissertations Center. 03 Jul 2015.

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Cardona Velasquez, Gustavo "Properties of Bright Variable Stars in Unusual Metal Rich Cluster NGC 6388." Electronic Thesis or Dissertation. Bowling Green State University, 2011. https://etd.ohiolink.edu/

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