Although pulsars can emit extremely strong light, it has not been easy to observe for a long time Even so, recently, with the help of some telescopes, astronomers have found perhaps the brightest pulsar to date - PSR j0523-7125 It is reported that as a neutron star, pulsars can emit radiation beams from the poles and produce light pulses when the beam rushes through the earth.
Pulsar PSR j0523-7125 imagination (from: ozgrav)
These bright pulses flash very fast, usually only a few seconds or even milliseconds apart. Take PSR j0523-7125 found in the Large Magellanic Cloud as an example, its frequency flickers three times per second.
Although it is just a dwarf galaxy orbiting our Milky Way galaxy, astronomers found pulsars 10 times brighter than other pulsars.
However, what puzzles us most is - how did it escape so long under the observation of many telescopes?
What is a Pulsar - NASA Goddard(via)
The researchers pointed out that the pulsar has an unusual feature to maintain its "stealth" state - because its radiation beam is very wide, which means that the pulse "turns on" for a much longer time than most pulsars.
Assuming a distant background galaxy, relevant investigations can easily ignore its light. However, with the help of the askap radio telescope in Australia, the researchers used its unique "Sunglasses" filter.
Askap radio telescope antenna at dawn (from: CSIRO)
Because the pulsar's magnetic field is very extreme, it will produce highly polarized light - it is difficult for most instruments to distinguish it from ordinary light, which askap can do.
In fact, when studying the askap data, researchers noticed a highly polarized object in the Large Magellanic Cloud. Its brightness has been changing for months.
When the filter is off, the background is quite complicated. When the filter is turned on, the pulsar is quite conspicuous. (from yunanming Wang)
Interestingly, when they carried out follow-up observations through other instruments, they did not observe any objects in the X-ray, visible or infrared bands - until the meerkat radio telescope in South Africa confirmed that it was an unusual pulsar.
15 / 64 points of meerkat radio telescope in South Africa (from sarao)
Professor Tara Murphy, from the University of Sydney, said:
This is the first time that we can retrieve the polarization of pulsars in a systematic and conventional way. At the same time, we also hope to find more pulsars with the help of this technology.
Due to the unusual characteristics of this pulsar, even if it is quite bright, previous studies have always missed it.
Group photo of Yuanming Wang and Professor Tara Murphy
Details of this study have been published in the recently published Astrophysical Journal( https://iopscience.iop.org/article/10.3847/1538-4357/ac61dc ) ) In the journal.
The original title was "discovery of PSR j0523-7125 as a circularly polarized variable radio source in the Large Magellanic Cloud".