Astronomers have been collecting data for generations, and the sad fact is that not all of it has yet been fully analyzed. There are still discoveries hiding in the dark recesses of data archives strewn throughout the astronomical world. Some of them are harder to access than others, such as actual physical plates containing star positions from more than a hundred years ago. But as more and more of this data is archived, astronomers also keep coming up with ever more impressive tools to analyze it. A recent paper from Cyril Tasse of the Paris Observatory and his co-authors, published recently in Nature Astronomy describes an algorithm that analyzes hundreds of thousands of previously unknown data points in radio telescope archives - and they found some interesting features in it.
Radio telescopes are a mainstay of the astronomer’s arsenal. These massive dishes allow them to capture light in the radio frequency spectrum, and see things like supernovae and black holes merging. But, while they are watching whatever particular event they are interested in, they are also capturing data on hundreds of background stars - and even potentially some exoplanets. While signals from those are filtered out in the original analysis, they remain in the archives awaiting an enterprising research group to try to understand them.
Doing so is quite the task, though. It would take an estimated 180 years of work to manually check the “hidden” background images that even only 1.4 years of data from the European LoFAR radio telescope collected. That’s a lot of work for an unsure payoff, since no one was sure what was happening in those background images.
A brief video on the LoFAR telescope, which collected the data used in the study. Credit - AstronNL YouTube ChannelSo the researchers developed a system to analyze that snippet of background radio data, which they call Multiplexed Interferometric Radio Spectroscopy - or RIMS. This acronym is likely French as the English spelling would sound a lot like a former Russian space station. A press release from Cornell, where paper author Jake Turner is a research associate, described it as casting a fishing net where it is able to capture a bunch of fish, rather than a fishing rod, where researchers would only analyze one particular signal.
Even in that 1.4 years worth of data, the researchers found over 200,000 new radio signals. Most of them were likely caused by solar flares of the stars being monitored. But some were probably a dynamic of an exoplanet interacting directly with its host star’s magnetic field. Basically it could be thought of as a super-intense version of the auroras we have here on Earth.
Despite the paper’s focus being about analyzing a bunch of background events, the authors did concentrate on one particular system - GJ 687. In that system, a Neptune-sized planet has a magnetic field that is crashing into its star’s magnetic field, creating radio waves that travel all the way to us. Understanding that dynamic could help RIMS and other programs like it scan the background sky of many radio telescope images for similar situations, potentially helping future astrobiological surveys narrow in on planets that have magnetospheres, which we think might be a pre-requisite to the formation of complex life.
This isn’t the first time we’ve detected a radio emission from an exoplanet - as Jake Turner, a co-author on the current study, explains. Credit - Carl Sagan Institute YouTube ChannelThere’s plenty of other data to analyze, though, and 1.4 years on one particular radio telescope is not even a fraction of a percent of all the radio astronomy data available out there. And RIMS appears to be a tool that can be applied across a wide variety of radio telescopes. With 200,000 signals in only 1.4 years, there are undoubtedly millions more just hiding in data archives throughout the world. Who knows what we’ll find when we start to analyze this treasure trove of background data - but some of it at least is sure to be interesting.
Learn More:
Cornell - Novel way to detect signals from stellar and exoplanetary systems unveiled
C. Tasse et al. - The detection of circularly polarized radio bursts from stellar and exoplanetary systems
UT - How To Detect Magnetic Fields Around Exoplanets
UT - Planetary Habitability Depends on its Star's Magnetic Field