系外行星凌星時間的變化之研究

由於系外行星 Qatar-1b 和HAT-P-23b 的凌星時間的變化之研究，尚未有明顯的結論。對於Qatar-1b系統，我們觀測並提供 10 條新的凌星光度曲線且研究分析凌星時間的變化。我們在假警報率 (false-alarm probability)為35%所對應的頻率之正弦模型，得到最小的簡化卡方檢定 (reduced chi-square )為 2.14，所得到的凌星參考時間為2455647.63345 ± 0.00008 (BJD)，軌道週期為 1.4200236 ± 0.0000001 (day)。對於 HAT-P-23b系統，我們觀測並提供了4條新的凌星光度曲線且研究分析凌星時間的變化。我們在假警報率 (false-alarm probability)為36%所對應的頻率在正弦模型下，得到最小的簡化卡方檢定 (reduced chi-square )為 0.94，所得到凌星參考時間為 2456135.49914 ± 0.00015 (BJD)，軌道週期為 1.2128866 ± 0.0000001(day)，另外我們更新了兩個系統的軌道半長軸與恆星的半徑比，並且計算了恆星潮汐因子。

關鍵字

系外行星；凌星時間的變化

並列摘要

Motivated by the unsettled conclusion on whether there are any transit timing variations (TTVs) for the exoplanet Qatar-1b and HAT-P-23b, we decided to study these two systems. For Qatar-1b, ten new light curves are presented and the TTV analysis with a baseline of 1400 epochs are performed. The sinusoidal model provides a good fitting with minimum reduced chi-square χ2red = 2.14, and the false-alarm probabilities of corresponding frequency is 35.2%. A new ephemeris with the reference time T0 = 2455647.63345 ± 0.00008 (BJD), the period P=1.4200236±0.0000001 (day) is obtained. For HAT-P-23b, four light new light curves as presented, and the TTV analysis with a baseline of 1600 epochs are performed. The sinusoidal model provides a good fitting with minimum reduced chi-squareχ2red = 0.94 and the false-alarm probability of corresponding frequency is 36.3%. A new ephemeris with the reference time T0 = 2456135.49914 ± 0.00015 (BJD), the period P = 1.2128866±0.0000001 (day) In addition, the updated orbital semi-major axis and planetary radius in the unit of stellar radius are provided, and the lower limit of modified stellar tidal quality factor is also determined for these two systems.