Sunday, December 17, 2023

Mysterious Signals From Space Are Getting Stranger, Scientists Say

Victor Tangermann
Sat, December 16, 2023 


Blipped Out

Ever since the first fast radio burst was discovered in 2007, scientists have been racing to understand the unusual flashes of radio waves emanating from extremely distant locations.

Some of these signals blip at astonishingly regular intervals, while some blast out extremely powerful flashes all at once, lighting up ground-based radio dishes like a Christmas tree for mere milliseconds.

Some FRBs emit as much energy in a fraction of a second as the Sun does in a few days. One signal that astonished astronomers earlier this year had been pulsing every 20 minutes since at least 1988.


And while scientists can still only hazard a guess as to what's behind them, the latest fast radio burst that was just discovered is only adding to the mystery — and highlighting just how much we still have to learn about the celestial phenomenon.
Ready SETI Go

As detailed in a new study published in the Monthly Notices of the Royal Astronomical Society this week, researchers spotted a "never-before-seen" burst dubbed FRB 20220912A using the SETI Institute's Allen Telescope Array, a collection of 42 antennae stretching out across the Cascade Mountains in California.

Over two months, the team detected 35 bursts from a single source. Unlike previous FRBs that repeated over time, the team noticed that the signal dropped in the center frequency of the bursts, kind of like a "celestial slide whistle," as CNN put it.

Despite their best efforts, the team wasn't able to detect a regular timing between each of the bursts.

Strange as that is, the findings could still help scientists get a better sense of where to look for more signals like it.

"This work is exciting because it provides both confirmation of known FRB properties and the discovery of some new ones," said SETI Institute researcher and lead study author Sofia Sheikh in a statement.

Scientists are still hunting for a source behind these FRBs. One popular theory that some have since put forth is that these signals could be released by the extremely magnetized remains of a collapsed star that might be emitting these radio waves like a cosmic lighthouse.

"We’re narrowing down the source of FRBs, for example, to extreme objects such as magnetars, but no existing model can explain all of the properties that have been observed so far," Sheikh added.

More on FRBs: Scientists Intercept Signal That Took 8 Billion Years to Reach Earth


Mysterious never-before-seen deep space radio signal found beyond Milky Way

Chris Oberholtz
Sat, December 16, 2023 

Mysterious never-before-seen deep space radio signal found beyond Milky Way

A team of astronomers says they have detected a never-before-heard radio signal that offers insights into the mystery of uncharted deep space.

This signal is known as a Fast Radio Burst (FRB), a bright flash of radio light lasting for a few milliseconds and originating from beyond the Milky Way.

Some FRBs repeat themselves, and a new study published in the Monthly Notices of the Royal Astronomical Society has shed new light. The study has detected a highly active repeating FRB signal behaving differently than anything previously detected.

"This work is exciting because it provides both confirmation of known FRB properties and the discovery of some new ones," said lead author Sofia Sheikh, of the SETI Institute in California.

Over a two-month period, Sheikh and other scientists observed 35 FRBs from a single source, FRB 20220912A. They discovered a fascinating pattern emerging from their observations.

Most repeating FRBs gradually get lower in pitch as they go on, according to astronomers. However, FRB 20220912A is different. It has a never-before-seen change in pitch that sounds like a cosmic slide-whistle which can be heard when the data is converted into a sound clip using a xylophone.

Dynamic spectra (or "waterfall" plots) for all the bursts from FRB 20220912A detected using the Allen Telescope Array, the frequency-averaged pulse profiles, and the time-averaged spectra.

The high-pitched notes are at the beginning of the clip, while the low-pitched notes are at the end, like someone playing a xylophone and repeatedly hitting the lowest note, scientists at the SETI Institute report.

Astronomers believe some FRBs are caused by a type of neutron star called a magnetar. These neutron stars have very strong magnetic fields and are the cores of dead stars.

"We’re narrowing down the source of FRBs, for example, to extreme objects such as magnetars, but no existing model can explain all of the properties that have been observed so far," Sheikh said.

Other ideas suggest that FRBs could also be produced by colliding neutron stars or merging white dwarfs.

The latest research is another step forward in the quest to unlock the secrets of FRBs, Sheikh said, which generate as much energy in a thousandth of a second as our Sun does in an entire year.

Original article source: Mysterious never-before-seen deep space radio signal found beyond Milky Way

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