We have analyzed 210 data of daily sunspot observations made during the period of January 3 to December 31 in 2000 and presented the daily relative sunspot numbers. For this work we estimated the conversion factors to derive the relative sunspot numbers: k=0.72 for the 20 cm refractor and k=0.56 for Solar Flare Telescope in KAO. During the year of 2000, our annual average of relative sunspot numbers is found to be 99.4. This number is obtained from the averaged daily number of 8.9 spot groups, in which there are about 62.5 distinct spots observed. According to the appearance of 423 spot groups, our analysis shows that the mean life time of the spot groups is about 4 day and 12.0 hours.

• 심경진(한국천문연구원) | K. J. SIM (Korea Astronomy Observatory)
• 문용재(한국천문연구원) | Y.-J. MOON (Korea Astronomy Observatory)
• 이청우(한국천문연구원) | C.-W. LEE (Korea Astronomy Observatory)
• 장비호(한국천문연구원) | B. H. CHANG (Korea Astronomy Observatory)
• 우화성(한국천문연구원) | H. S. WOO (Korea Astronomy Observatory)