https://chandra.si.edu/photo/2025/lprt/
- ASKAP J1832 belongs to a class of objects that vary in radio wave intensity in a regular way over tens of minutes.
- This source is different, however, because it also changes in X-ray intensity as seen by NASA’s Chandra X-ray Observatory.
- This is the first time that such an X-ray signal has been found in a "long period radio transient."
- Researchers are still trying to determine the nature of ASKAP J1832, including whether it is a highly magnetic neutron star or white dwarf.
- Scientists have discovered a star behaving like no other seen before, giving fresh clues about the origin of a new class of mysterious objects.
ASKAP J1832 belongs to a class of objects called “long period radio transients” discovered in 2022 that vary in radio wave intensity in a regular way over tens of minutes. This is thousands of times longer than the length of the repeated variations seen in pulsars, which are rapidly spinning neutron stars that have repeated variations multiple times a second. ASKAP J1832 cycles in radio wave intensity every 44 minutes, placing it into this category of long period radio transients.
Using Chandra, the team discovered that ASKAP J1832 is also regularly varying in X-rays every 44 minutes. This is the first time that such an X-ray signal has been found in a long period radio transient.
In this composite image, X-rays from Chandra (blue) have been combined with infrared data from NASA’s Spitzer Space Telescope (cyan, light blue, teal and orange), and radio from LOFAR (red). An inset shows a more detailed view of the immediate area around this unusual object in X-ray and radio light.
Using Chandra and the SKA Pathfinder, a team of astronomers found that ASKAP J1832 also dropped off in X-rays and radio waves dramatically over the course of six months. This combination of the 44-minute cycle in X-rays and radio waves in addition to the months-long changes is unlike anything astronomers have seen in the Milky Way galaxy.
The research team argues that ASKAP J1832 is unlikely to be a pulsar or a neutron star pulling material from a companion star because its properties do not match the typical intensities of radio and X-ray signals of those objects. Some of ASKAP J1832’s properties could be explained by a neutron star with an extremely strong magnetic field, called a magnetar, with an age of more than half a million years. However, other features of ASKAP J1832 — such as its bright and variable radio emission — are difficult to explain for such a relatively old magnetar.
On the sky, ASKAP J1832 appears to lie within a supernova remnant, the remains of an exploded star, which often contain a neutron star formed by the supernova. However, the research team determined that the proximity is probably a coincidence and two are not associated with each other, encouraging them to consider the possibility that ASKAP J1832 does not contain a neutron star. They concluded that an isolated white dwarf does not explain the data but that a white dwarf star with a companion star might. However, it would require the strongest magnetic field ever known for a white dwarf in our galaxy.
A paper by Ziteng Wang (Curtin University in Australia) and collaborators describing these results appears in the journal Nature. Another team independently discovered this source using the DAocheng Radio Telescope and submitted their paper to the arXiv on the same day as the team led by Dr Wang. They did not report the X-ray behavior described here.
I can think of a "new" type of physics that should be able to solve this easily, starting by reversing their model of stellar evolution:https://www.ice.csic.es/?view=article&id=777&catid=8
The object, known as ASKAP J1832-0911, emits pulses of radio waves and X-rays for two minutes every 44 minutes. This is the first time objects like these, called long-period transients (LPTs), have been detected in X-rays. It is located in our Milky Way galaxy, about 15,000 light-years from Earth. Astronomers hope it may provide insights into the sources of similar mysterious signals observed across the sky. Detecting these objects using both X-rays and radio waves may help astronomers find more examples and learn more about them.
A new cosmic phenomenon
LPTs, which emit radio pulses that occur minutes or hours apart, are a relatively recent discovery. Since their first detection by ICRAR researchers in 2022, ten LPTs have been discovered by astronomers across the world. Currently, there is no clear explanation for what causes these signals, or why they ‘switch on’ and ‘switch off’ at such long, regular and unusual intervals.
“This object is unlike anything we have seen before. ASKAP J1831-0911 could be a magnetar (the core of a dead star with powerful magnetic fields), or it could be a pair of stars in a binary system where one of the two is a highly magnetised white dwarf (a low-mass star at the end of its evolution)”, Dr Wang said.
“However, even those theories do not fully explain what we are observing. This discovery could indicate a new type of physics or new models of stellar evolution”, he adds.
https://reciprocalsystem.org/paper/at-t ... -evolution
So is this a white dwarf at the early stage of it's life, with them detecting the quantized jump transitions?
- The dwarf star has an inverse density gradient. The heaviest elements are on the surface of the star, and the lightest at the center.
- Also, since the atoms are dispersed in time rather than space, they cannot be measured using spatial detection methods, and the star, itself, appears to be composed of what is viewed on the surface: a solid, metallic ball.
- It is very hot. So hot that its radiation is well into the X-ray band.
- A normal sun will condense and heat up over time, the white dwarf (being inverse) will cool down and expand over time.
- As with all super-luminal matter, transitions occur in quantized jumps, rather than a continuous transition.
- As matter cools and drops back into space, it appears as light gases in the center of the star. When gas pressure in the white dwarf builds up, it erupt onto the hot surface, combusting, and producing a "nova" flare.
- The intermediate speed range within the white dwarf will produce a intense magnetic field.
- The ultra-high speed ranges at the surface of the star will produce thredules, a co-magnetic phenomenon.7