Well, this sure is one parade that's getting rained out of existence. A spectacular astronomical event that had been predicted for 2022 now isn't going to happen after all.

Early in 2017, scientists forecast the collision of two stars in the constellation Cygnus – something that would result in a rare and wonderful phenomenon visible to the naked eye. And the news spread like wildfire.

The two stars, located a mere 1,800 light-years from Earth, are currently locked in a spiralling death dance. According to the researchers, in the year 2022 – just a few short years away – they were going to collide.

And it wasn't just going to be a small blip in the night sky. When binary star system KIC 9832227 finally merged, it was going to produce a luminous red nova - increasing in brightness 10,000-fold, which would be visible from Earth for some time.

Now, though, that prediction has been nixed.

*Sad trombone*

A team of researchers led by astronomer Quentin Socia at San Diego State University has meticulously pored over the mathematics, and come up with a different result.

And the original researcher - astronomer Larry Molnar from Calvin College - has agreed with this new finding.

"Good science makes testable predictions," Molnar said.

"There have been a few other papers that have tried to poke at our project, and we've been able to poke back - criticisms that just don't fly.  But this one does fly, and I think they have a good point. This illustrates how science can be self-correcting."

The problem was found to be with the data Molnar and his team used to make the prediction.

KIC 9832227 is a fascinating system. The two stars are locked in with each other so tightly that they take just 11 hours to perform one full orbit. And they're so close that they actually share parts of their atmospheres, what is known as a contact binary.

They're also an eclipsing binary, oriented in just the right way that, as they orbit, they eclipse each other from our point of view here on Earth.

The prediction was based on the timings of minimum light – that is, the point at mid-eclipse in which the light from the binary system is at its lowest – from all available sources.

Molnar and his team used Calvin Observatory data between 2013 and 2016. Between 2007 and 2013, they used data from other observatories. There was a long gap in the data before 2007, but in 1999, one observation had been taken as part of the Northern Sky Variability Survey.

Socia and his team got their hands on previously unpublished archival data from 2003, taken as part of the NASA Ames Vulcan Project. And they found that the eclipses were occurring half an hour later than predicted by Molnar's merger hypothesis.

They re-ran the numbers, and the timings after 2007 checked out. But that one 1999 datapoint was awry - a full hour later than it was supposed to be.

The culprit? A typo.

Yep. In the paper that originally described the 1999 data, published in 2004, a typo resulted in the misrepresentation of the timing of the eclipse by 12 hours. This error was carried into Molnar's team's calculations.

Interestingly, the typo didn't occur in the article's preprint (it's the mjd, or Modified Julian Date, value in Table 6).

The eclipse absolutely couldn't have occurred at the time the published paper stated, either. Socia calculated where KIC 9832227 would have been at that specific time. It would have been below the horizon. The telescope would not have been been able to see it.

This isn't to say that, at some point in the future, KIC 9832227 isn't going to go kaboom; but that point isn't going to be in 2022.

And yes, we're a bit deflated about it; but ultimately, while science can giveth, its ability to taketh away is equally important.

"This is arguably the most important part of the scientific process. Knowledge advances the most when bold predictions are made, and people question and test those predictions," Socia said.

"Often the most exciting discoveries happen when our expectations are not met. This is a good example of how scientists from different parts of the world can work together to better understand how our universe works, bringing with them new pieces to the puzzle."

So it's not going to be KIC 9832227. But eventually a binary star is going to collide, and there are now a lot of eyes out there looking for it.

"The authors of the manuscript don't question our fundamental premise, which is to say 'this is something that you should be looking for, this is something that can be found,'" Molnar said.

"It's actually because they agree with that fundamental premise that they dug deeper. And so the search for an impending stellar merger continues."

The research has been published in The Astrophysical Journal Letters.

Astronomers studying pulsars may have finally unravelled why these mysterious pulsating objects appear to send different kinds of signals into space – by tracking the immense cloud trails of their nebulae.

Thanks to images taken by NASA's Chandra X-ray Observatory, a new analysis of two very contrasting pulsars shows that pulsars' energy emissions may only be visible to Earth from certain angles – which could explain a mystery that's puzzled scientists up until now.

Pulsars are a kind of neutron star – an extremely dense core of matter left over once a massive star has exploded in a supernova.

What sets pulsars apart from other neutron stars are their pulsating radio waveemissions – a tightly focused beam of electromagnetic radiation that rapidly rotates around the pulsar much like the light shone from a lighthouse.

While pulsars were long categorised by the emission of these radio waves, more recently researchers have found that some pulsars also generate a different kind of energy signal – gamma rays – and the distinction has puzzled astronomers for almost a decade.

Geminga, artist's impression. Credit: Nahks Tr'Ehnl

"It's not fully understood why there are variations between different pulsars," says researcher Bettina Posselt from Pennsylvania State University.

"One of the main ideas here is that pulse differences have a lot to do with geometry – and it also depends on how the pulsar's spin and magnetic axes are oriented with respect to line of sight whether you see certain pulsars or not, as well as how you see them."

One of the ways scientists can study pulsars is by tracking what's called pulsar wind nebulae – clouds of energetic particles that form doughnut-shaped rings called tori, which stretch out into tail-like structures as they spin off from the rapidly rotating pulsar.

Thanks to the Chandra X-ray Observatory, scientists can now study these nebulae, which helps us understand the different kinds of magnetic activity that pulsars exhibit – and also why we only pick up certain emissions from them.

"This is one of the nicest results of our larger study of pulsar wind nebulae," says one of the team, physicist Roger W. Romani from Stanford University.

"By making the 3D structure of these winds visible, we have shown how one can trace back to the plasma injected by the pulsar at the centre."

Two very divergent kinds of pulsar wind nebulae can be seen in the pulsars Geminga – which is approximately 800 light-years from Earth – and BO355+54, which is about 3,300 light years away.

In the case of Geminga (shown above), you can see the pulsar has three distinct tails making up its nebulae. Of these, the two long tails are called lateral tails, and are thought to spin off from Geminga's magnetic poles.

These lateral tails stretch out for more than half a light-year from Geminga, while a third, shorter tail also emanates from the pulsar.

The researchers think the positioning of Geminga's poles is why we can only pick up gamma rays from the pulsar on Earth – but not radio emissions.

"The tails seem to tell us why that is," says Posselt. "For Geminga, we view the bright gamma ray pulses and the edge of the pulsar wind nebula torus, but the radio beams near the jets point off to the sides and remain unseen."

Top Left X-ray: NASA/CXC/PSU/B.Posselt et al; Infrared: NASA/JPL-Caltech. Top Right X-ray: NASA/CXC/GWU/N.Klinger et al; Infrared: NASA/JPL-Caltech. Illustrations by Nahks Tr'Ehnl.

By contrast, B0355+54 (pictured above alongside Geminga) has its radio waves angled at Earth, which is how we're able to detect it – even though we can't pick up its gamma rays.

"For B0355+54, a jet points nearly at us so we detect the bright radio pulses while most of the gamma-ray emission is directed in the plane of the sky and misses the Earth," says one of the team, Oleg Kargaltsev from George Washington University.

"This implies that the pulsar's spin axis direction is close to our line-of-sight direction and that the pulsar is moving nearly perpendicularly to its spin axis."

While there's still a lot to learn about pulsars, the new discoveries help explain why we've only picked up distinct emissions from these kinds of cosmic objects before – and lets researchers study particle physics in ways that would be impossible to replicate in a lab on Earth.