冬の星空は，天の川をはじめ，明るい星がたくさん輝いています． 中でも， オリオン座のベテルギウス，おおいぬ座のシリウス， こいぬ座のプロキオンは目を惹きます． この3つの星を結んだ三角形を，冬の大三角形と呼びます． Map of Constellation
In the winter sky, many bright stars including the Milky Way are twinkling. Especially, Betelgeuse of Orion, Sirius of Canis Major and Procyon of Canis Minor are shining brightly. The triangle which connected these three stars is called Winter Triangle. By courtesy of A.Fujii

Spectra of Winter Triangle in Wide Field

	左は，カメラにグリズム分光器をつけて撮影した写真です． 星のすぐ右側に，スペクトルが写っています． スペクトルを見ると， ベテルギウス(αOri)とシリウス(αCMa)は， 他の星に比べてやや赤い部分が強いのがわかります． これは温度が低いことを表しています． またオリオン星雲(M42)では輝く点（輝線）が見えています． Map of Constellation and Stellar Spectra
The top is the photograph taken with the camera which attached the grism spectrometer. The spectrum is seen to stellar right-hand side. If a spectrum is seen, Betelgeuse and Sirius looks strongly in red region compared with other stars. This expresses that temperature is low. Moreover, in the Orion Nebula, emission can be seen. By courtesy of K.Ohnishi (Nagano National College of Technology)