We find that a sunspot with positive polarity had an obvious counter-clockwise rotation and resulted in the formation and eruption of an inverse S-shaped filament in NOAA active region ( AR ) 08858 from 2000 February 9 to 10 .
The sunspot had two umbrae which rotated around each other by 195 degrees within about twenty-four hours .
The average rotation rate was nearly 8 degrees per hour .
The fastest rotation in the photosphere took place during 14:00UT to 22:01UT on February 9 , with the rotation rate of nearly 16 degrees per hour .
The fastest rotation in the chromosphere and the corona took place during 15:28UT to 19:00UT on February 9 , with the rotation rate of nearly 20 degrees per hour .
Interestingly , the rapid increase of the positive magnetic flux just occurred during the fastest rotation of the rotating sunspot , the bright loop-shaped structure and the filament .
During the sunspot rotation , the inverse S-shaped filament gradually formed in the EUV filament channel .
The filament experienced two eruptions .
In the first eruption , the filament rose quickly and then the filament loops carrying the cool and the hot material were seen to spiral into the sunspot counterclockwise .
About ten minutes later , the filament became active and finally erupted .
The filament eruption was accompanied with a C-class flare and a halo coronal mass ejection ( CME ) .
These results provide evidence that sunspot rotation plays an important role in the formation and eruption of the sigmoidal active-region filament .