Puppis A is a bright X-ray supernova remnant in the southern sky, seen behind the Vela Remnant, from which a neutron star is fleeing at high speed.
At a glance
| type | supernova remnant |
|---|---|
| distance from the Sun | 7,180 light-years (2.2 kpc) |
| its light left it | 7,180 years ago |
| size in the piece | about 100 light-years acrossmodel |
Read off the piece’s own catalogue, the same values it draws with. Model marks a property of the piece’s galaxy model rather than a measurement.
About Puppis A
Puppis A is a supernova remnant bright in X-rays, its shock heating the gas around it until it shines in X-rays and running into a dense cloud on one side. It overlaps the Vela Remnant on the sky, but lies much farther away, so the two are unrelated.
Near its centre is a neutron star moving away from the remnant’s middle at very high speed, nicknamed the cosmic cannonball. The explosion seems to have kicked it in one direction while heavier debris flew the other way, a clue to how asymmetric supernovae can be.
What you see in the piece
It is drawn as a hollow shell of shocked gas far behind the much nearer Vela Remnant; in visible light both are faint, and the radio band shows their shells.
Measured or modelled
Its age is inferred from the motion of the neutron star and the expansion of its debris. The drawn extent is modelled.
Questions
What is the cosmic cannonball in Puppis A?
It is the neutron star left by the explosion, moving away from the remnant’s centre at very high speed, kicked by an asymmetric supernova.
How far away is Puppis A?
Puppis A is about 7,180 light-years (2.2 kpc) from the Sun, far behind the Vela Remnant.