We are starting to reach the point in astronomy where we can pretty readily identify major changes in the sky in many different colors of light. The results aren’t always great – data wasn’t as sensitive to faint objects and wasn’t as high a resolution – but that older data is generally good enough to say, “Hey, there is something new here.”

And sometimes those new things are the first of their kind to ever be identified.

For decades, the Very Large Array of telescopes in New Mexico has been scanning large regions of the sky, mapping radio sources and identifying everything from actively feeding black holes, to regions of furious star formation. I used the FIRST survey as part of my research many moons ago, and today’s researchers are able to use a new VLA Sky Survey named VLASS to see things even better.

Since 2018, VLASS has been doing roughly yearly measurements designed specifically to look for things that change, and in year one of its efforts, it found a flashing point that hasn’t been seen before. This object, cataloged as VT 1137-0337, is located in a dwarf galaxy 395 million light years away. This system is undergoing radical star formation and is the kind of place we can expect to see supernovae and the results of recent supernovae.

Based on these three facts – the object is new, it is flashing in the distinctive way of a rapidly rotating pulsar, and it is in a star-bursting galaxy – researchers believe we are seeing a newly formed pulsar emerging from the nebula it formed within. Pulsars are created when massive stars run out of nuclear fuel in their core and collapse under their own gravity. The outer layers of the star will end up igniting and exploding back out creating the light and eventual nebula of a supernova. The core, however, just collapses under its own mass, and gravity will actually crush the core so much that protons and electrons combine into neutrons. The ball of neutrons will rotate exceedingly fast, and if it has a powerful magnetic field, it will flash with each rotation. Initially, this pulsar will be completely hidden behind the material that was once the outer layers of the star, but over time it can thin out its surroundings as it forms what is called a pulsar wind nebulae.

We know all these details from seeing supernovae and seeing pulsars that have been around a while and then running the maths to see how things must evolve to get from one stage to the next. This object may fill in the gap in our observations. According to researcher Gregg Hallinan: Based on its characteristics, this is a very young pulsar — possibly as young as only 14 years, but no older than 60 to 80 years.

While not this young, the 1,032-year-old Crab Nebula still has a – for astronomy – young pulsar in its core. A comparison of these two objects indicates that VT 1137-0337 isn’t just younger, it’s also more powerful. According to led researcher Dillon Dong: The object we have found appears to be approximately 10,000 times more energetic than the Crab, with a stronger magnetic field. It likely is an emerging ‘super Crab’.

Alternatively, it might be an even more rare object – a magnetar – a kind of neutron star with an exceedingly powerful magnetic field that can emit radio bursts that can be seen at massive distances. Dong goes on to say: In that case, this would be the first magnetar caught in the act of appearing, and that, too, is extremely exciting. Our discovery of a very similar source switching on suggests that the radio sources associated with FRBs also may be luminous pulsar wind nebulae.

These observations show us that we can never say we are done looking at the sky. New things are always being born, dying, and sometimes creating stellar remnants. We look forward to seeing how the object evolved over the coming years and decades as the universe gives us a chance to see an undead star being born.

More Information

NRAO press release