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The Galaxy's Biggest Telescope Just Took the Highest-Resolution Measurement Ever

A distant pulsar was measured with a million times the precision of the previous record. The results are equivalent to glimpsing the double-helix structure of our DNA from the moon.
A pulsar in the Crab Nebula. Image via NASA/ESA/

Scientists based out of the International Centre for Radio Astronomy Research (ICRAR) announced that they have produced “the highest resolution measurement ever achieved.” To get a sense of the magnitude, ICRAR compares the technique to peering into the double helixes of our genes from the surface of the moon.

Naturally, we're not talking about any ordinary telescope. Instead of relying on conventional lenses, the ICRAR team used the vast interstellar medium surrounding a pulsar as a makeshift cosmic magnifying glass.

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Pulsars are a class of neutron stars characterized by their high energy beams of electromagnetic radiation. From our perspective on Earth, these blasts are segmented into a series of clockwork pulses tied to the star's rotation. The result is similar to how a lighthouse beam appears to flash on and off at night, when actually, the bulb is always on and revolving.

The ICRAR team focused on capturing radio radiation from Pulsar B0834+06, paying close attention to the way the interstellar medium distorted the radio bursts. Using that data, they created a composite image from thousands of sub-images of the pulsar. The resolution of this reconstructed image had an angular resolution of 50 picoarcseconds, beating out the previous record of 50 microarcseconds by a factor of a million.

An illustration of a pulsar's gamma ray bursts and magnetic fields. Image via NASA.

“Compared to other objects in space, neutron stars are tiny—only tens of kilometers in diameter—so we need extremely high resolution to observe them and understand their physics,” radio astronomer Jean-Pierre Macquart said in a statement. “The best we could previously do was pointing a large number of radio telescopes across the world at the same pulsar, using the distance between the telescopes on Earth to get good resolution.”

The study's lead author, Ue-Li Pen of the Canadian Institute of Theoretical Astrophysics, looks forward to using the new technique to probe deeper into the mysteries of these peculiar stars. “Pulsars have the highest brightness temperature of any known process in the universe, up to 10^{26} degrees,” Pen told me over email. “It is not known why they appear so hot, and for the past half century, scientists have been working on ways to make this happen.”

“There are competing ideas, many related to magnetic fields, but there hadn't been a way to test which idea is right. Using the new scintellometry approach, we can now directly measure the emission position.”

Fortunately, the Australian Research Council recognized the significance of Pen and Macquart's new technique, and awarded them a grant of $344,000 to continue their research. “We are in the process of organizing observing campaigns to simultaneously observe pulsars with the world's biggest radio telescopes, and study a number of pulsars,” Pen told me.

This is not the first time that astronomers have used enormous cosmic phenomena as telescopic aids. Galaxies can be used to observe the young universe through a process called gravitational lensing, and earlier this year, astronomers used a distant quasar as a giant flashlight for rooting out dark matter filaments. Using the optical properties of galaxies, quasars, and the interstellar medium, astronomers are now able to peer deeper into space than ever before.