We have determined the disk size of Be stars by using Hα emission. We observed spectra of Be stars with telescope in SNU, equipped with SB SGS (Santa Babara Self Guided Spectrograph) and CCD ST-8. The size of disk of Be stars was estimated with the Be star model of Grundstrom & Gies (2006). This study suggests that the medium resolution spectra taken with small telescope equipped with commercial spectrograph are useful to estimate the approximate size of the Hα emitting disk around Be stars.

• 안대건(서울과학고등학교) | DAE-GUN AHN (Seoul Science High School)
• 배장호(서울과학고등학교) | JANG-HO BAE (Seoul Science High School)
• 이상각(서울대학교 물리·천문학부) | SANG-GAK LEE (Department of Physics and Astronomy, Seoul National University)
• 신영우(서울대학교 물리·천문학부) | YOUNG-WOO SHIN (Department of Physics and Astronomy, Seoul National University)
• 고연경(서울대학교 물리·천문학부) | YEON-GYUNG KO (Department of Physics and Astronomy, Seoul National University)
• 강석철(서울과학고등학교) | SUK-CHUL KANG (Seoul Science High School)