我們利用鹿林天文台的LOT及SLT望遠鏡以及托洛洛山美洲際天文台（Cerro Tololo Inter-American Observatory，CTIO）的SMARTS 1.3m望遠鏡觀測兩顆IIn型超新星：SN 2008ip及SN 2009au以取得其光變曲線。SN 2008ip在2008年12月31日發現，其宿主星系NGC 4846之z值為0.015124，發現時的亮度則為15.7等。SN 2009au則是在2009年3月11日發現，其宿主星系ESO 443-21之z值為0.009404，發現時的亮度為16.4等。IIn型超新星是一種光譜中帶有Hα窄發射線的類型，窄發射線來自於震波與環星物質的交互作用，這種超新星類型較為少見，約佔所有超新星數量的三個百分點。過去也有人對其他IIn型超新星進行觀測，例如SN 1988Z、SN 1995G以及SN 2006tf，我們比較SN 2008ip及SN 2009au和這幾顆IIn型超新星的光變曲線、色曲線，發現SN 2008ip及SN 2009au亮度較其他IIn型超新星低，且光度下降速率也較快，由色曲線可以看出它們和一般IIn型超新星的顏色變化方式相似，但由於周圍有濃厚的環星物質包覆造成初期不斷變紅的其間比其他型超新星來得久。 We have observed two type IIn supernovae, SN 2008ip and SN 2009au, to obtain the light curves by LOT and SLT at Lulin observatory and SMARTS 1.3m at CTIO. SN 2008ip, with mag= 15.7 at discovery, was first observed on 2008.12.31 in host galaxy NGC 4846 with z= 0.015124. SN 2009au, with mag=16.4, was discovered on 2009.3.11 in host galaxy ESO 443-21 with z= 0.009404. Type IIn supernovae is a rare kind of supernovae with the narrow line emission, especially at Hα line. The narrow emission lines come from the interaction between the shock wave and the circumstellar medium. SN 2008ip and SN 2009au are with those of SN 1988Z, SN 1995G and SN 2006tf. We compare the light curves, color curves and spectra of them to understand the characteristic of the progenitors and the supernova environments. We noticed that SN 2008ip and SN 2009au are fainter than other type IIn supernovae, and decay faster than others. SN 2008ip and SN 2009au had the similar color curves with type IIn supernovae, but the era of increasing B-V value are longer than other type supernovae. That might caused by the dense circumstellar medium.
