Nova KT Eridani於2009年11月爆發,並於2009年11月14日到達了最大亮度5.4等,之後其亮度下降非常快速,並且在2011年3月的時候回到了寧靜態,亮度約為15等。在2010年3月31日SWIFT太空望遠鏡24小時持續監測這顆星的X-ray變化,我們利用地面望遠鏡在台灣鹿林、美國亞歷桑那州Tenagra以及智利CTIO天文台SMARTS提供可見光同步觀測。我們比較在同步觀測這一天X-ray和可見光的關係。此外我們蒐集了美國變星觀測者協會 (AAVSO) 觀測此目標星的星等變化,以及新星爆發後期我們持續監測,得到此顆星從爆發到回到寧靜期的光變曲線,並且做週期分析找出了56.7天的周期,我們認為這很有可能是雙星系統中,吸積盤上熱點 (hot-spot) 所造成的週期。我們的研究支持KT Eri是顆再發性的新星 (recurrent nova),而其伴星很有可能是K0光譜型態的巨星。 The nova KT Eri exploded in November 2009. The peak brightness reached 5.4 mag at 2009 November 14.63 UT. After then, the brightness has faded very fast and went into its quiescence (V~15) in the spring 2011. On March 31, 2010, Swift undertook a 24-hour monitoring of this nova, for which we provided ground-based CCD imaging photometric measurements taken with telescopes at Lulin (Taiwan), Tenagra (Arizona), and SMARTS/CTIO (Chile) covering the day before, during, and the day after the Swift campaign. The X-ray and optical light curves are compared. We also present long-term optical light curves and find a period of 56.7 days, which we interpreat as due to the hot spot on the WD accretion disk. We propose the companion of KT Eri to be a giant of an early K type.