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The Korean Astronomical Society (한국천문학회)
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VARIABLE STARS IN THE REGION OF THE OPEN CLUSTER NGC 225

산개성단 NGC 225 영역의 변광성

  • Received : 2016.10.04
  • Accepted : 2016.10.26
  • Published : 2016.12.31
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Abstract

Through time-series BV CCD photometry of the open cluster NGC 225 region, we have detected 30 variable stars including 22 new ones. They are five ${\delta}$ Scuti-type variable stars, a slowly pulsating B star, six eclipsing binary stars and 18 semi-long periodic or slow irregular variables, respectively. We have performed multiple-frequency analysis to determine pulsation frequencies of the ${\delta}$ Scuti-type stars and a slowly pulsating B star, using the discrete Fourier transform and linear least-square fitting methods. We also have derived the periods and amplitudes of 6 eclipsing binaries and a long-period variable star from the phase fitting method, and presented the light curves of all variable stars. A slowly pulsating B star is a member of NGC 225, but ${\delta}$ Scuti-type stars are not members from the positions in the color-magnitude diagram and the radial distancies from the center of the cluster. From Dias et al. (2014, A&A, 564, 79), only three variable stars including the slowly pulsating B star are members of clusters: two are in NGC 225 and one is in Stock 24. But a variable star in Stock 24 is not a member of the cluster because of its position of color-magnitude diagarm.

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References

  1. Bilir, S., Funda, B. Z., Talar, Y., et al., 2016, CCD UBV Photometry and Kinematics of the Open Cluster NGC 225, Advances in Space Research, 58, 1900 https://doi.org/10.1016/j.asr.2016.06.039
  2. Breger, M., 1979,  Scuti and Related Stars, PASP, 91, 5 https://doi.org/10.1086/130433
  3. Breger, M., et al., 1993, Nonradial Pulsation of the Delta-Scuti Star Bu-Cancri in the Praesepe Cluster, A&A, 271, 482
  4. Dias, W. S., Monteiro, H., Caetano, T. C., Lepine, J. R. D., Assa n, M., & Oliveira, A. F., 2014, Proper Motions of the Optically Visible Open Clusters Based on the UCAC4 Catalog, A&A, 564, 79 https://doi.org/10.1051/0004-6361/201323226
  5. Hoag A. A., Johnson H. L., Iriarte B., Mitchell R .I., Hallam K. L. & Sharpless S., 1961, Photometry of Stars in Galactic Cluster Fields, Publ. Us. Nav. Obs., XVII part VII, 347.
  6. Jeon, Y. -B., 2008, Variable Stars in the Region of an Open Cluster M50, PKAS, 23, 17
  7. Jeon, Y. -B., 2009, Variable Stars in the Region of an Young Open Cluster M29 (NGC 6913), PKAS, 24, 19
  8. Jeon, Y. -B., Kim, S. -L., Park, Y. -H., et al., 2005a, Short-Period Variability Survey (SPVS) in BOAO, PKAS, 20, 21
  9. Jeon, Y. -B., Park, Y. -H., Nam, K. -H., et al., 2005b, New Variable Stars around the Cepheid Variable TU Cas, PKAS, 20, 29
  10. Jeon, Y. -B., Lee, M. G., Kim, S. -L., & Lee, H., 2003, New SX Phoenicis Stars in the Globular Cluster M53, AJ, 123, 3165
  11. Jeon, Y. -B., Nam, K. -H., Park, Y. -H., et al., 2007, Preliminary Results for Short-Period Variability Survey (SPVS): New Field Variable Stars, PKAS, 22, 141
  12. Jeon, Y. -B., Park, Y. -H., Lee, U. Y., et al., 2013, Variable Stars in the Region of CYG OB3 Association Centered on the Open Cluster NGC 6871 II, PKAS, 28, 831
  13. Jeon, Y. -B., Park, Y. -H., & Lee, S. M., et al., 2015, Variable Stars in the Region of the Open Cluster NGC 1039 (M34), PKAS, 30, 821
  14. Jin, H., Kim, S. -L., Lee, C. -U., et al., 2004, Reclassi cation of ROTSE-I  Scuti Stars with Multiband Photometry and Fourier Decomposition, AJ, 128, 1847 https://doi.org/10.1086/423908
  15. Kim, S. -L. & Lee, S. -W., 1995, CCD Photometry of a Delta Scuti Star in an Open Cluster II. BT CNC in the Praesepe, JKAS, 28, 197
  16. Lata,S., Pandey, A. K., Panwar, N., Chen, W. P., Samal, M. R., & Pandey, J. C., 2016, Variable Stars in Young Open Star Cluster NGC 7380, MNRAS, 456, 2505 https://doi.org/10.1093/mnras/stv2800
  17. Lattanzi M. G., Massone G., & Munari U., 1991, Memberships and CM Diagrams of Young Open Clusters. I. NGC 225, AJ, 102, 177 https://doi.org/10.1086/115865
  18. Massey, P. & Davis, L. E., 1992, A User's Guide to Stellar CCD photometry with IRAF
  19. Phelps, R. L. & Janes, K. A., 1994, Young Open Clusters as Probes of the Star Formation Process. I. An Atlas of Open Cluster Photometry, AJ Suppl., 90, 31 https://doi.org/10.1086/191857
  20. Rose, M. B. & Hintz, E. G., 2007, A Search for Low-Amplitude Variability in Six Open Clusters Using the Robust Median Statistic, AJ, 134, 2067 https://doi.org/10.1086/522963
  21. Samus, N. N., Durlevich, O. V., et al., 2004, Combined General Catalogue of Variable Stars (Samus+2004), VizieR Online Data Catalog, 2250
  22. Stetson, P. B., 1987, DAOPHOT - A Computer Program for Crowded- eld Stellar Photometry, PASP, 99, 191 https://doi.org/10.1086/131977
  23. Subramaniam, A., Mathew, B., & Kartha, S. S., 2006, Star Formation in the Region of Young Open Cluster - NGC 225, Bull. Astr. Soc. India, 34, 315
  24. Sung, H., Lim, B.; Bessell, M. S., et al., 2013, Sejong Open Cluster Survey (SOS). 0. Target Selection and Data Analysis, JKAS, 46, 103
  25. Zacharias, N., Finch, C. T., Girard, T. M., Henden, A., Bartlett, J. L., Monet, D. G., & Zacharias, M. I., 2012, UCAC4 Catalogue, VizieR On-line Data Catalog: I/322. Originally published in: 2012 yCat.1322, 0