UsnoA2.0 星表目标分布

   
     赤纬0~20度带状天区，星等18~19.5度。

    select starid,ra,dec,blue_mag from stars where dec between 32400000 and 39600000 and blue_mag >= 18 and blue_mag <= 19.5;

赤经范围	Usno坐标	目标个数
0 ~  60	0 ~  21600000	1067863
60 ~ 120	21600000 ~  43200000	5846500
120 ~ 180	43200000 ~  64800000	1505055
180 ~ 240	64800000 ~  86400000	1456496
240 ~ 300	86400000 ~  108000000	13453555
300 ~ 360	108000000 ~  129600000	4958824

    共计：28288293


    赤纬0~20度带状天区，星等18~18.5度。

    select starid,ra,dec,blue_mag from stars where dec between 32400000 and 39600000 and blue_mag >= 18 and blue_mag <= 18.5;

    共计：7668638