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Variable stars, particularly eclipsing binaries, are very essential astronomical occurence in order to open our knowledge on star properties. Advanced technology <br /> <br /> <br /> <br /> <br /> in astronomical instruments, enriched obeservational technique, and...
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| Format: | Final Project |
| Language: | Indonesia |
| Online Access: | https://digilib.itb.ac.id/gdl/view/16282 |
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| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | Variable stars, particularly eclipsing binaries, are very essential astronomical occurence in order to open our knowledge on star properties. Advanced technology <br />
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in astronomical instruments, enriched obeservational technique, and upgraded both data quality and quantity have broaden our horizon about the special characteristic <br />
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of eclipsing binaries, notably in formation, structure, evolution, and other related studies. Despite these advances, 90% of all bright variable stars (m < 12) have not been discovered (Paczynski 2001). To remedy this lack of data on variable stars, astronomers have initiated astronomical survey projects. For surveys constitute the <br />
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backbone of astronomy, and many breakthrough resulted from them. <br />
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All-Sky Automated Survey (ASAS, Pojmanski 1997) is one of the observing projects whose ultimate goal is the photometric monitoring of variable stars with I < 13. <br />
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Since its first light in 1997, ASAS has collected 50,099 variable stars, with 11,076 of them are classified as eclipsing binary systems (Paczynski et al. 2006). <br />
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Since the number of data points in each ASAS eclipsing binary light curve are sparse, time-wise (unevenly spaced data), period determination of some systems is <br />
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not a straightforward process. Period determination based on Analysis of Variance method (AoV, Schwarzenberg-Czerny 1989) does not always yield the best result. <br />
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Therefor, the present work is focused on the period determination of the eclipsin binaries. For some of such systems, comparisons are drawn between the implementations of Lomb-Scargle algorithm and Phase Dispersion Minimization (PDM) method in determining their periods. Both methods are implemented to 30 ASAS eclipsing binaries to find a better solution. Those 30 ASAS eclipsing binaries are selected systematically and optimized for follow up utilizing small telescope available at Bosscha Observatory, based on their RA, dec, and Vmax. <br />
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We will analyzed the peridicity of the 30 selected objects using computational program, scargle.pro1 (Joern Wilms 2000) for Lomb-Scargle periodogram and pdm.pro2 (Marc W. Buie 1992) for PDM. The period determination process is semi-automatic. The best candidates among statistically possible periods have to be selected under human supervision. Finally, each period analysis method will give its best results. Lomb-scargle algorithm works <br />
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well in sinusoidal light curve, in this case, the contact eclipsing binaries. While PDM is superior when applied to all types of eclipsing binaries. |
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