The audience of Stargazing Live on ABC TV has discovered at least one new supernova — an exploding star — as part of the citizen science effort launched on Tuesday evening.
Thousands of citizen scientists supplied more than 1 million new data points in a matter of hours, helping to classify 18,000 images from the Skymapper telescope at the Siding Spring observatory.
Four of those participants identified a flash of light emitted from a galaxy 1.1 billion light years away.
Then in the small hours of Wednesday morning, the Anglo-Australian Telescope at Siding Spring took time out of its current assignment to turn and stare at that galaxy, catching some of the explosion’s afterglow.
It was that observation that allowed astronomers to confirm that the flash was indeed a type Ia supernova.
One of the four discoverers was Pip Newling from Sydney. She said it was “ridiculously exciting” to be part of the surprisingly rapid progress made by the project.
“I have to fess up, it was probably a joint effort. Neither my boyfriend nor I can remember which one we actually hit — we were sharing the task. But I got the email!”
This is just the first finding to emerge from the Supernova Sightings project, run by the Skymapper team at the Australian National University and hosted by zooniverse.org.
The initiative and its thousands of participants still have much more work to do and probably many more discoveries to make.
“1.1 billion light years means exactly that,” Stargazing Live presenter Brian Cox said.
“When that star exploded, there were no living things beyond the ocean on the Earth.
“The light was almost here when humans evolved — and it was very nearly here when we began to do astronomy.
“Then we invented television, and eventually we made a television show … and ABC viewers saw it last night.
“If it’d happened a week later, we’d never have seen it.”
Beacons for measuring the universe
In less than a day, several thousand participants joined in and classified an average of more than 200 images each.
That meant that the available images from the Skymapper telescope at Siding Spring were all assessed 60 times, on average.
More images are being added to the project tonight, from both Skymapper and the Pan-STARRS telescope in Hawaii.
“It’s wonderful that we’ve found our first supernova,” said Professor Chris Lintott from the University of Oxford, the principal investigator at zooniverse.org.
“Who knows what else is out there, lurking in the data.”
The participants all have the chance to get their names on the scientific record.
“We recognise citizen scientists by listing the first three people to find a previously unknown supernova in the discovery when we report it to the International Astronomical Union,” said Dr Anais Moller from the ANU Research School of Astronomy and Astrophysics.
Particularly notable is that the distant flash, currently catalogued as “AT2018BWQ”, appears to be a type Ia supernova.
When stars die they can explode in a variety of ways. Type Ia supernovae are particularly precious to astronomers because are very consistent; they always explode with the same brightness, so it is easy to infer how far away they are.
That makes them useful beacons for calculating some of the fundamental properties of the cosmos — like its size, its age and how fast it is expanding.
As a consequence, the Supernova Sightings project should be able to make a very slightly revised estimate of those properties in the next few days — especially if a handful more type Ia explosions are unearthed in the data.
“There’s a shared pot of these things, and as ever with science, each individual measurement … adds to the accuracy of the overall measurement. So this will go into that pot,” Professor Lintott said.
“That means we can say — it’s a gimmick but it’s a good gimmick — if the universe, as determined by this supernova, is slightly older than the average, well we’ve just made the age of the universe a bit older.
“I’m guessing it might shift by up to a hundred million years, either way.”
Given the cosmos is approximately 14 billion years old, this is not a vast correction — and of course it can be rewritten every time a few more type Ia supernovae enter the record books.
But it is not every day a TV show, with a little help from its audience, makes such calculations — and the Stargazing Live team is excited.
“It’s looking like we’ll be able to make an independent estimate of the age of the universe,” Professor Cox said.