Astronomers have a new way to bypass Earth’s atmosphere

Radio telescopes have a bonus over optical telescopes, in that radio telescopes can be utilized even in cloudy situations right here on Earth. That is as a result of the longer wavelengths of radio waves can go by clouds unhindered.

Nonetheless, some wavelengths are nonetheless partially obscured by parts of Earth’s ambiance, particularly by the ionosphere which traps human-made Radio Frequency Interference (RFI).

Astronomers have developed a brand new calibration method that enables them to take sharp photographs in low radio frequencies—between 16 and 30 MHz—for the primary time, bypassing the affect of the ionosphere. The astronomers say this can permit them to check issues like plasmas emanating from historical black holes and even perhaps detect exoplanets that orbit small stars.

The method was developed by a world staff of researchers led by astronomers from Leiden College within the Netherlands.

“It is like placing on a pair of glasses for the primary time and now not seeing blurred,” mentioned Christian Groeneveld from Leiden College, who led the analysis, which is now published in Nature Astronomy.

The astronomers used the LOFAR telescope in Drenthe, the Netherlands, which is at the moment probably the greatest low-frequency radio telescopes on this planet. They modified a calibration method that has been used to enhance observations for observing in radio at increased frequencies, round 150 MHz.

“We hoped that we may additionally lengthen this system to decrease frequencies, beneath 30 MHz,” mentioned Reinout van Weeren, additionally from Leiden College, who got here up with the concept. “And we succeeded.”

To check their method, they studied a number of galaxy clusters that had beforehand solely been studied intimately at increased frequencies.

“Our observing technique consisted of concurrently observing a shiny main calibrator and the goal fields,” the staff wrote of their paper. “By scheduling the commentary after midnight, we minimized RFI attributable to the inner reflection of terrestrial RFI by the ionosphere, which is considerably worse through the day, as ionizing radiation from the sun will increase the column density of ions within the ionosphere.”

Then, they break up up their discipline of view into a number of smaller “aspects” and self-calibrated every side individually, in opposition to the calibrator object. “This yields an improved picture and mannequin of the sky, partly corrected for course dependent results,” they wrote. They then repeated the calibrations three extra occasions.

This was the primary time radio photographs at frequencies between 16 and 30 MHz have been taken. Due to this knowledge, the astronomers mentioned that the radio emissions from these clusters will not be evenly distributed throughout the complete cluster, however quite there’s a spot sample.

Based on the researchers, the brand new calibration method makes it attainable to check radio phenomena at frequencies that have been beforehand hidden.

“There’s, in fact, an opportunity that we’ll ultimately uncover one thing sudden,” mentioned Groeneveld.