Magnetars are a special type of neutron star famous for their extremely strong magnetic fields. These magnetic fields are the most powerful known in the universe, trillions of times stronger than Earth’s magnetic field. Magnetars are formed when certain massive stars collapse and explode, leaving behind these dense, compact stars with intense magnetism.

Magnetars emit strong bursts of X-rays and gamma rays, which makes them interesting to astronomers studying high-energy space events. Their magnetic energy can cause starquakes on their surface, releasing large amounts of energy.

Let’s clear up the other options:
- **Quasars** are distant, bright objects powered by supermassive black holes, not neutron stars.
- **Magneto** and **Magnetta** are incorrect terms and do not refer to any known astronomical objects.

Understanding magnetars helps scientists learn about extreme physics and the life cycle of massive stars. They challenge our knowledge of matter under intense magnetic forces and help improve models of how stars evolve.

In short, the neutron star sub-class with the highest magnetic field is called a **Magnetar**, making it one of the most fascinating objects in space.