# Calculating the output of Seyferrt Galaxy

1. Mar 6, 2012

### skydivephil

Im trying to calcuate the energy output of Saigtarius A star if it were to accrete material at the same rate as a typical Seyfert Galaxy which I understand to be about 1 solar mass per year (correct?). Im getting an answer that looks way too low. As I understand it we should get a number something like 10^37
Here are my calculations:

The radius of Sagittarius A star, the black hole at the centre of our galaxy is a number I couldn’t find. However it’s mass is easily available: 3.6 mio solar mass
We can compute the radius using the Schwarzschild formula
Rs=2GM/c^2
Where Rs is the Schwarzschild radius
G is the gravitational constant = 6.67*10^-11
M is the mass in kg is 7.2*10^36
C is the speed of light 3*10*8
So we have 2*6.67*10-11*7.2*10^36/9*10^16
= 1.07*10^10
No we can calculate the accretion energy using
GM/R = 6.67*10^-11*2*10^30/1.0*10^10
=1.25*10^10
Mauybe the radisu of Sag A* is much alrgher than normal AGn, or Ive made a mistake somehwere. Any ideas?