利用Philips 840K及Andor iXon相機進行小角距雙星之散斑干涉觀測

Abstract

在地面的天文觀測解析度受到大氣擾動的影響而受限，利用散斑干涉的觀測方法所得到短時間的曝光影像經過處理後可以穫得被觀測雙星的角距及方位角訊息。本研究利用商用相機及研究級的Frame transfer CCD進行觀測，兩次的觀測都在鹿林山天文台使用口徑1公尺的蓋賽格林式望遠鏡完成，並分別在2006年四月2~3日使用Philips 840K CCD以及2007年二月9-11日使用Andor iXon CCD取得14及21組雙星的影像資料。第一次觀測使用Castor做為參考星校準，第二次則是使用60公分間距的雙狹縫做像素對應角以及拉線式的方法做影像旋轉的校準。第一次在角距的量測誤差為0.017角秒，方位角誤差為0.89度，第二次的角距誤差為0.087角秒，方位角誤差為3.39度。For the observations of binaries, angular separation could approach to the diffraction limit of the telescope using speckle interferometry method. Fast exposure within 20ms can freeze and take the star spread to many spots called speckle and the imaging technique is speckle interferometry. The distribution area of speckle is called seeing disk and angular separations of the binaries are usually closer than seeing. In this research, binaries are studied with their speckle images taken by a commercial webcam and a frame transfer CCD and images reductions are processed with autocorrelation function to analyze their spatial information. Two observations at Lulin Observatory of National Central University were carried out on April, 2~3, 2006 and February, 9~11, 2007. For the observation of 2006, April, 2~3, a Philips 840K webcam were used to observe 14 targets and 13 binaries were resolved. The targets were calibrated separation and position angle with a wide binary star as reference, Castor. The standard error is 0.017 arcsec in separation and 0.89 degree in position angle. For the observation on 2007, February, 9~11, a Andor iXon frame transfer CCD was used to observe 21 targets and 17 binaries were resolved. The targets were calibrated separation with a 60-cm interval double slits mask and calibrated position angle with drift scan image of each target, and standard error 0.087 arcsec in separation and 3.39 degree in position angle.