Classic radial sunburst effect
This is the coveted classic look, made using a circle with a dashed stroke outline - change the default of 12pt to something more like 100pt. Then basically expand that (select stroke and fill) and with direct select (a) lasso the inner end points, then Right Click: Average: Both .... to project all the "rays" into the centre of the original circle.
Create a filled rectangle on top (I guess any shape would do) and select it and the burst (V), Object > Clipping Mask > Make
Retro radial element rotational sunburst (think '70s wall clock)
This is more a way of creating spindles emanating from a central point, as in the retro logo genre. Having created one spindle (pen or line tool, add arrow via stroke panel if desired), the spindle is radially repeated by Effect: Distort: transform and the number of spindles is enetered into the angle field as 360/#spindels. The repeat value is the number of spindles minus one ie #spindles-1 (20 spindles would require 20-1=19 repeats, as the original spindle is already in position)
Add decorations to spindle by testing on the original one, then dragging that object in the layers panel into the effect-created group.