Punctum might be a brand new mysterious astronomical object that has never been observed before
.We discovered it with the ALMA radiotelescope, which was observing the active galactic nucleus of the nearby galaxy NGC 4945, 11 million light-years away, shown above. This enigmatic pointy source of millimeter-range highly polarized electromagnetic radiation was discovered by accident because it showed in the field of view.
We don’t know what it is, but it must be very small to emit radiation that is polarized, which is usually produced by objects with a very strong magnetic field, like magnetars. Except that this one emits radiation four to five orders of magnitude more powerfully than any known magnetar (10,000 to 100,000 times) and even 10 to 100 times stronger than supernovas.
It’s not a transient source of radiation like these powerful explosions because it has been continuously observed since 2023. Furthermore, it’s not visible in visible light or other ranges of electromagnetic radiation.
We can only guess what it is. Maybe it’s a very powerful magnetar that is located in an unusual environment that made it so powerful. This signal cannot come from a remnant of a supernova because they are too large to emit such a powerful polarized radiation.
Perhaps if we find more of these mysterious Punctums elsewhere, we might finally figure out what it is.