在這個研究工作裡，我們想要探測XO-1這個系外行星系統是否存在第三個星體，會對XO-1b繞行XO-1產生擾動，我們是藉由觀察XO-1b的軌道運行周期是否有周期性的微小變化來達成此目的。因此，我們對XO-1這個行星系統的兩次凌日現象共進行了三次觀測並取得三條光變曲線。此外，我們還搜集了二十八次凌日事件的光變曲線，共計三十五條。接著，我們對這三十八條光變曲線進行分析，並取得凌日事件的時間中點，然後計算其與預期時間之間的差值。我們在時間差值中尋找可能的周期性震盪訊號，並用觀測數據進行擬合，然後以χred2來表示擬合結果的吻合程度。我們獲得無週期性震盪之擬合結果的χred2為2.1764，有震盪訊號且頻率為0.483985之擬合結果的χred2為1.7962，而震盪頻率是0.10706的χred2則為2.0867。

We observed two newly transits of the XO-1 planetary system. The observations of one of these transit events are done by using the 46-cm telescope hosted by Wise Observatory in Israel. The observations of the other one are done by using both 104-cm and 130-cm telescopes located at ARIES in India. We investigate the possibility for the transit timing variations (TTVs) in the orbital period of XO-1b that may aroused by the existents of an additional planet in this system, so we collected 28 transits from public data and analyzed with our own data. After the O-C diagram of the XO-1 system is obtained and analyzed, we found that a null TTV produces a fit with χred2=2.1764. We also find that the ephemeris with a sinusoidal function of a frequency 0.483985 has a fit with χred2=1.7962 and the one of a frequency 0.10706 has a fit with χred2=2.0867.

Agol, E., Steen, J., Sari, R., and Clarkson, W. 2005, MNRAS, 359, 567
Brijesh Kumar and Kuntal Misra, 2006, Users Manual of 104-cm Sampurnanand Telescope
Eastman, J., Siverd, R., and Gaudi, B. S. 2010, PASP, 122, 935
Everett, M. E., and Howell, S. B. 2001, PASP, 113, 1428
Holman, M. J., and Murray, N. W. 2005, Science, 307, 1288
Holman, M. J., Winn, J. N., Latham, D. W., et al. 2006, ApJ, 652, 1715
Jiang, I.-G. et al., 2013, AJ, 145, 68
Maciejewski, G., Dimitrov, D., Neuhuser, R., et al. 2011, MNRAS, 411, 1204
McCullough, P. R., et al. 2006, ApJ, 648, 1228
McCullough, P. R., Stys, J. E., Valenti, J. A., Fleming, S. W., Janes, K. A., and Heasley, J. N. 2005, PASP, 117, 783
Official website of Aryabhatta Research Institute of Observational-Sciences (http://www.aries.res.in/)
Official website of the Florence and George Wise Observatory (http://wiseobs.tau.ac.il/)
Ping Chien, et al. 2012, NTHU master thesis, Observations and Study of Transit Events in the Exoplanet System WASP-10
Poddany S., Brat L., Pejcha O., New Astronomy 15 (2010), pp. 297-301, Exoplanet Transit Database. Reduction and processing of the photometric data of exoplanet transits (arXiv:0909.2548v1)
Ram Sagar, et al. 2011, ASI Conference Series, Vol. 00, pp 19