A pulsar is a rapidly rotating neutron star that emits electromagnetic radiation.
Describe the formation of a neutron star from a massive star.
State one characteristic property of a neutron star.
A typical neutron star can be modelled as a sphere with mass M≈2.8×1030 kgM \approx 2.8 \times 10^{30}\,\text{kg}M≈2.8×1030kg and radius R≈11 kmR \approx 11\,\text{km}R≈11km.
Show that the average density of this neutron star is similar to the average density of an atomic nucleus.
An astronomer uses a radio telescope to observe a pulsar.
During one full rotation of the pulsar, the telescope receives a single radio pulse. This pulse is modelled as a triangular peak of power against time. The power rises linearly from 0 W0\,\text{W}0W at t=0t = 0t=0 to a peak of 8.5×10−22 W8.5 \times 10^{-22}\,\text{W}8.5×10−22W at t=3.0 mst = 3.0\,\text{ms}t=3.0ms, and then falls linearly back to 0 W0\,\text{W}0W at t=10.0 mst = 10.0\,\text{ms}t=10.0ms.
Calculate the total energy received by the telescope during one full rotation of the pulsar.
The collecting surface area of the telescope is 5200 m25200\,\text{m}^25200m2. The distance to the pulsar is 650 pc650\,\text{pc}650pc.
By assuming that the radio emission from the pulsar is emitted equally in all directions, estimate the total radio energy emitted by the pulsar during one full rotation. (Use 1 pc≈3.1×1016 m1\,\text{pc} \approx 3.1 \times 10^{16}\,\text{m}1pc≈3.1×1016m)
