Open a new flash document and change the document size to 450 X 300 and choose a background color of your choice.
Click on the PolyStar tool (click on the rectangle and select PolyStar from the dropdown list).
Click on the Options button on the Properties panel:
Select star for style, select 5 for Number of Sides and leave the Star point size the default 0.50:
Select a fill color for your star and select no stroke:
Draw out a star on the center of your stage:
Center the star on the center of the canvas:
Convert the star to a symbol by clicking on it with the selection tool and then clicking F8.
At the symbol dialog box name the symbol star and click Movie Clip as the behavior.
Copy the symbol, Edit Copy or Cntrl + C, then Edit Paste in Place (Shift + Cntrl + V) seven times. This will give you 8 instances of the star. You want see but one star because you pasted on top the copied star.
Now we will place each star on its own layer. Select all the stars by clicking off the one star, then drawing an imaginary square around the star, then click Modify > Layer > Distribute to Layers.
Your stars should now be on their own layer.
Now we are going to select all the frames in 30. You could click each keyframe (black dot) and hold down the Shift key and continue to select all the keyframes in 30 or you could drag over the frames while holding down the left mouse. Make sure you start at the top of the Timeline then drag down.
Click F6 to place Keyframes in all the frames in 30:
Drag across all the frames in 60 and create keyframes for all the frames.
Click back on frame 30 and select the top star by clicking on it. drag it off the stage. Continue with the rest of the stars until all the stars are dispersed off the stage as shown below:
Click on the one of the stars on the stage with the selection tool. A blue box should show you that it is selected:
On the Properties panel select Alpha from the Color drop down list and turn the transparency down to 0%.
Continue to set all the stars in frame 30 to the above color and transparency alpha setting.
Drag anywhere between frames 1 and 30 selecting all the layers.
On the Properties panel select motion from the drop down Tween options:
Click anywhere between frames 30 and 60 and drag across all layers and select motion from the Tween options. Your timeline should look similar to the one below:
(click on the rectangle and select PolyStar from the dropdown list). 
and then clicking F8.
