These send energy out into space pulses not steadily like young stars

Pulsars.

Explanation:

Pulsars is an object related to something celestial that is something in space. Pulsars are considered to be a star associated with neutron stars that has high magnetic field, thus they (pulsars) may called neuron stars.

Because of the fact that they have high magnetic field they are known to produce electromagnetic radiation. It is very important to note that it is not all Pulsars that should be called Neutron stars.

The electromagnetic radiation that Pulsars produces are in pulses.