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Statistical Analysis and the OPEA Model of the White-Light Flares Occurring on Krüger 60B (DO Cep)

Published online by Cambridge University Press:  02 January 2013

Hasan Ali Dal
Hasan Ali Dal
Affiliation:
Department of Astronomy and Space Sciences, University of Ege, Bornova, 35100 İzmir, Turkey. Email: ali.dal@ege.edu.tr
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Abstract

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In this study, new observations and some results of statistical analyses are presented. The largest flare data set of DO Cep in the literature has been obtained with 89 flares detected in 67.61 hours of U-band flare patrol. First of all, the observations demonstrated that the star is one of the most active flare stars in respect to the computed flare frequency. Secondly, using the independent samples t-test, the detected flares were classified into two subtypes, and then they were modelled. Analysing the models demonstrated that the fast and slow flares occurring on the star can be separated with a critical value of the ratio of their decay time to rise time. The critical value was computed as 3.40. According to this value, the fast flare rate is 20.22%, while the slow flare rate is 79.78%. Besides, there is a 39.282 times difference between the energies of these two types of flares. However, the flare equivalent durations versus the flare rise times increase in similar ways for both groups. In addition, all the flares were modelled with the one-phase exponential association function. Analysing this model, the plateau value was found to be 2.810. Moreover, the half-life value was computed as 433.1 s from the model. The maximum flare rise time was found to be 1164 s, while the maximum flare total duration was found to be 3472 s. The results of the flare timescales indicate that the geometry of the flaring loop on the surface of the star might be similar to those seen on analogues of DO Cep. Consequently, considering both the half-life value and flare timescales, the flares detected on the surface of DO Cep get maximum energy in longer times, while the geometries of the flaring loops or areas get smaller.

Keywords

methods: data analysismethods: statisticalstars: spotsstars: flarestars: individual (DO Cep)
Type
Research Article
Information
Publications of the Astronomical Society of Australia , Volume 28 , Issue 4 , 2011 , pp. 365 - 377
Copyright
Copyright © Astronomical Society of Australia 2011

References

Benz, A. O. & Güdel, M., 2010, ARA&A, 48, 241Google Scholar
Contadakis, M. E., Mahmoud, F. M., Mavridis, L. N. & Stavridis, D., 1982, IBVS, 2088, 1Google Scholar
Dal, H. A. & Evren, S., 2010, AJ, 140, 483CrossRefGoogle Scholar
Dal, H. A. & Evren, S., 2011a, AJ, 141, 33CrossRefGoogle Scholar
Dal, H. A. & Evren, S., 2011b, PASJ, 63, 427CrossRefGoogle Scholar
Dawson, B. & Trapp, R. G., 2004, in Basic and Clinical Biostatistics (City: The McGraw-Hill Companies Inc. Press), 61, 134, 245Google Scholar
Doyle, J. G., 1996a, A&A, 307, 162Google Scholar
Doyle, J. G., 1996b, A&A, 307, L45Google Scholar
Favata, F., Flaccomio, E., Reale, F., Micela, G., Sciortino, S., Shang, H., Stassun, K. G. & Feigelson, E. D., 2005, ApJS, 160, 469CrossRefGoogle Scholar
Gershberg, R. E., 1972, Ap&SS, 19, 75Google Scholar
Gershberg, R. E., 2005, Solar-Type Activity in Main-Sequence Stars (New York: Springer), 53, 191, 192, 194, 211, 325, 360Google Scholar
Gershberg, R. E. & Shakhovskaya, N. I., 1983, Ap&SS, 95, 235Google Scholar
Glebocki, R. & Gnacinski, P., 2005, yCat., 3244, 0Google Scholar
Green, S. B., Salkind, N. J., & Akey, T. M., 1999, Using SPSS for Windows: Analyzing and Understanding Data (Upper Saddle River, N.J.: Prentice Hall Press), 50Google Scholar
Grinin, V. P., 1983, Activity in Reddwarf Stars, Proc. Seventy-first Colloq., Astrophys. Space Sci. Libr. 102, Dordrecht: Reidel, 613Google Scholar
Gurzadian, G. A., 1988, ApJ, 332, 183CrossRefGoogle Scholar
Hardie, R. H., 1962, in Astronomical Techniques, ed. Hiltner, W. A. (Chicago: Univ. Chicago Press), 178aGoogle Scholar
Haro, G. & Chavira, E., 1955, BOTT, 21, 3Google Scholar
Haro, G. & Parsamian, E., 1969, BOTT, 5, 45Google Scholar
Henry, T. J., Walkowicz, L. M., Barto, T. C. & Golimowski, D. A., 2002, AJ, 123, 2002CrossRefGoogle Scholar
Herr, R. B. & Brcich, J. A., 1969, IBVS, 329, 1Google Scholar
Hudson, H. S. & Khan, J. I., 1997, ASPC, 111, 135Google Scholar
Imanishi, K., Nakajima, H., Tsujimoto, M., Koyama, K. & Tsuboi, Y., 2003, PASJ, 55, 653CrossRefGoogle Scholar
Ishida, K., Ichimura, K., Shimizu, Y. & Mahasenaputra, , 1991, Ap&SS, 182, 227Google Scholar
Jenkins, J. S., Ramsey, L. W., Jones, H. R. A., Pavlenko, Y., Gallardo, J., Barnes, J. R. & Pinfield, D. J., 2009, A&A, 704, 975Google Scholar
Kirkup, L. & Frenkel, R. B., 2006, An Introductio n to Uncertainty in Measurement (Cambridge: Cambridge University Press)CrossRefGoogle Scholar
Kunkel, W., 1967. An optical study of stellar flare. Thesis. Austin, TexasCrossRefGoogle Scholar
Lacy, C. H., Moffett, T. J & Evans, D. S, 1976, ApJS, 30, 85CrossRefGoogle Scholar
Lacy, C. H., 1977, ApJS, 34, 479CrossRefGoogle Scholar
Landolt, A. U., 1992, AJ, 104, 340CrossRefGoogle Scholar
Leto, G., Pagano, I., Buemi, C. S. & Rodonó, M, 1997, A&A, 327, 1114Google Scholar
Mavridis, L. N. & Avgoloupis, S., 1986, A&A, 154, 171Google Scholar
Meištas, E. G., 2002, High-Speed Three-Channel Photometer (HSTCP) User's Guide, To Molétai version (Vilnius: Astronomical Observatory of Vilnius University)Google Scholar
Moffett, T. J., 1974, ApJS, 29, 1CrossRefGoogle Scholar
Motulsky, H., 2007, in GraphPad Prism 5: Statistics Guide, ed. Motulsky, H. (San Diego, CA: GraphPad Software Inc. Press), 94, 133Google Scholar
Nicastro, A. J., 1975, IBVS, 1045, 1Google Scholar
Osawa, K., Ichimura, K., Noguchi, T. & Watanabe, E., 1968, TokAB, No. 180Google Scholar
Oskanian, V. S., 1969, in Non-Periodic Phenomena in Variable Stars, Proc. AUI Coll. No 4., ed. Detre, L. (Budapest: Academic Press), 131CrossRefGoogle Scholar
Pandey, J. C. & Singh, K. P., 2008, MNRAS, 387, 1627Google Scholar
Petschek, H. E., 1964, in Proc. of AAS-NASA Symp. on the Physics of Solar Flares, ed. Hess, W. N., NASA SP-50, 425Google Scholar
Pettersen, B. R., 1991, MmSAI, 62, 217Google Scholar
Pettersen, B. R., Coleman, L. A. & Evans, D. S., 1984, ApJ, 282, 214CrossRefGoogle Scholar
Reeves, K. K. & Warren, H. P., 2002, ApJ, 578, 590CrossRefGoogle Scholar
Rodonó, M., 1990, IAUS, 137, 371Google Scholar
Schmitt, J. H. M. M. & Liefke, C., 2004, A&A, 417, 651Google Scholar
Skumanich, A. & McGregor, K., 1986, AdSpR., 6, 151Google Scholar
Söderhjelm, S., 1999, A&A, 341, 121Google Scholar
Spanier, J. & Oldham, K. B., 1987, An Atlas of Function (Washington D.C., USA: Hemisphere Publishing Corporation Press), 233Google Scholar
Tamazian, V. S., Docobo, J. A., Melikian, N. D. & Karapetian, A. A., 2006, PASP, 118, 814CrossRefGoogle Scholar
Van Den Oord, G. H. J. & Barstow, M. A., 1988, A&A, 207, 89Google Scholar
Van Den Oord, G. H. J., Mewe, R. & Brinkman, A. C., 1988, A&A, 205, 181Google Scholar
Vandenberg, D. A., Hartwick, F. D. A., Dawson, P. & Alexander, D. R., 1983, ApJ, 266, 747CrossRefGoogle Scholar
Veeder, G. J., 1974, AJ, 79, 702CrossRefGoogle Scholar
Vilhu, O., Neff, J. E., & Walter, F. M., 1986, in New Insight in Astrophysics, ESASP-263, ed. Rolfe, E. J., 113Google Scholar
Vilhu, O. & Rucinski, S. M., 1983, A&A, 127, 5Google Scholar
Walker, A. R., 1981, MNRAS, 195, 1029CrossRefGoogle Scholar
Wall, J. W. & Jenkins, C. R., 2003, in Practical Statistics For Astronomers (Cambridge: Cambridge University Press), 79CrossRefGoogle Scholar
Wilson, O.C., 1978, ApJ, 226, 379CrossRefGoogle Scholar