The stars of neutron are the hot remains and rapidly rotating of huge stars. Many are pulsar, who send radio signals that coincide with the earth, like seeing light from a lighthouse. Credit: Kevin Gill
At about 2,600 light years away, a dead star is sending signals for over the tomb.
The astronomers recently found the strange lighthouse, which seems to be a pulsar in slow motion – something that should not be possible.
“It is incredibly exciting to discover such a long-term pulsar,” says Yuanming Wang, post-dictate researcher at Swinburne University in Australia and the main author of an article on the discovery published on March 28 in The letters of Astrophysics magazine. “But what is even more exciting is that the new technique we have used is to open the door to find more hidden objects in the cosmos.”
Scientists now plan to look for more than these strange objects, who could help to fill the gap between traditional and well-understood pulsars and well-understood and the few that rotate-apparently impossibly-slow.
Slow and constant
The pulsars are like high -speed cosmic headlights. Dense nuclei left by huge stars that have exhausted the nuclear fuel and went to Supernova are made. Following the explosion, what remains of the star collapses in a six miles wider neutron star (10 kilometers). Since the original angular moment of the star (spin) is preserved, being crushed in such a small object means that its accelerates, in the same way that a skater turns faster when they pull their arms. Pulsar emit radiation beams from their poles; These rays then cross the universe while turning. If those rays indicate the earth, we receive a flash of light at each rotation, generally in radio wavelengths.
Pulsar pulsates with precision of the clock – literally – with the fastest flutters that flash tens of thousands of times per minute. Even the slower ones tend to flash at least every 10 seconds.
But in 2022, astronomers found an object that emitted radio impulses such as a pulsar, but much more slowly: only once every 18 minutes. Since then, scientists have discovered a handful of more than these objects, known as long -term transitors, with periods ranging from minutes to hours.
You would think that these could only be very slow, but there is a problem with that explanation. The energy of a pulsar derives from its rotating movement. Despite their regularity, the pulsars are in fact slowing gradually and the energy lost in that deceleration is converted into the radio beams they emit. Long -term transitors cannot be slow, because they are already going so slowly that the further loss of rotational energy is no longer sufficient to feed strong beams like those we see from them. (The point where a pulsar revolves too slowly to produce radio beams is called the pulsar death line. Pulsar that descend below this line stop emitting radio beams, so we stop seeing them as pulsar.)
Therefore, long -term transitors cannot be so slow AND So bright if they are caused by the same mechanisms as the rotation powered buttons. Some may still be neutron stars that behave in unexpected ways. Others could be completely different objects, such as white dwarfs or binary systems.
A missing connection
The recently discovered pulsar, called PSR J0311+1402, can offer new clues. With a period of 41 seconds, it turns much more slowly than the typical pulsars, but much faster than long -term transient. And astronomers think that this object halfway could be a missing bond between the two populations.
Scientists identified the star stroke with the Australian Pathfinder of the Square Array (Askap) and followed other radio observers to measure its brightness, period and polarization, which everyone indicates strongly that it is a pulsar. But he is still turning too slowly to be fed exclusively by the rotation.
“It does not adapt perfectly to the main theory of how pulsars emit radio waves,” says Wang. “If a pulsar turns too slowly, we shouldn’t see any radio emission. Yet this object is very slow”, leaving astronomers to ask where the energy that feeds its rays comes from.
Study this strange lighthouse and find more as if it could help astronomers learn more how long the transient of time generate their rays.
“I think there should be more objects like this waiting to be discovered,” says Wang. “At this moment, we see a space in the periods of rotation between well -known and transitors for a long term. The traditional pulsar research methods in general have not sought objects that turn more slowly by 10 seconds, which means that we could have lost them simply because we were not looking for them before!”
Astronomes generally find pulsars that use a single large radio and telescope, which cannot easily detect flashes less often about once every 10 seconds because the slower signals are weaker and more easily lost in the background noise. Long-term transitors are usually used using more radio antennas that work together-one method called interferometry. This method is less sensitive to fast flashes, because the combination of the signals of multiple telescopes requires long enough to be able to cloud or even delete rapid changes from the data. This lets pulsar with medium periods, such as PSR J0311+1402, in a blind point for both methods.
But he is changing, as this discovery shows. “Now we are using a new system with Askap called Craco, who [is] Perfect to capture objects in this missing range, “says Wang. It is the system that PSR J0311+1402 found PSR and could help astronomers understand where the cleansing and transitors begin in the long run, or if they are more similar than we believe in it.” Answering these questions will help us understand the entire population of the neutrical star and what feeds their emissions. “
The discovery and the mystery that underlines, show how much remains to know the cosmos.
“With the new radio structures that arrive online, we could find a lot of strange things in the sky,” said Michelle Collins, professor of astronomy at the University of Surrey in England who was not involved in the study, in a podcast. “We may find that this is the tip of the iceberg, with many more long -term neutron stars waiting to be discovered,” says Collins Astronomy.
