[syhprum (OP)]

I have just been reading about the power emitted in the collision of two neutron stars the figure quoted was 3*10^41 ergs/sec why not 3*10^34 Watts ?

[7anooch]

Because they're using cgs units, not SI (where watts would be more correct). This is largely due to convention and also the fact that many equations simplify when stated in cgs units.

[Bored chemist]

Most of the numbers they use  are so big they are written as powers of ten. If you are doing that, it hardy matters.
Is  3*10^41 harder to write than  3*10^34 ?