A Group of Astronomers Discovers a Mysterious Object in Space That Repeats an X-Ray Signal Every 44 Minutes

A group of astronomers has discovered an object that sends out X-ray and radio signals exactly every 44 minutes, a discovery that has been published in the journal Nature.

The ASKAP radio telescope was responsible for finding the source emitting radio waves every 44 minutes. Credit: CSIRO

When we observe the universe, we can detect different types of electromagnetic signals depending on where we look. The frequency and energy of electromagnetic signals provide information about the type of object and the phenomenon that originated the signal. Some objects can pulse and emit signals at regular intervals, such as neutron stars. But in addition to these, some types of black holes and binary systems can also generate periodic emissions.

In 1967, astronomer Jocelyn Bell detected regular and rapid radio signals. The periodicity was so precise that, for a brief time, they were even considered possible signals from an extraterrestrial civilization. Bell even nicknamed the source “Little Green Men.” They later discovered they were neutron stars.

Astronomers have recently discovered a new object that emits pulses of radio waves and X-rays every 44 minutes. Unlike neutron stars, which are faster, this mysterious object has not yet been fully identified.

It is located approximately 16,000 light-years away, and its emission across multiple bands of the electromagnetic spectrum and its unusual periodicity suggest it could be some type of new object.

Objects that Emit Pulses

Pulsars are rapidly spinning neutron stars that emit beams of electromagnetic radiation. The magnetic field is misaligned with their rotation, so as they spin, these regular pulses are emitted and detected from Earth, resembling a lighthouse. The precision of these pulses, which can maintain regularity down to fractions of a millisecond, makes them some of the most accurate natural “clocks” in the universe.

The precision of pulsars is so extreme that they function as true beacons and timers for some observations. Even tests of general relativity rely on pulsars.

But pulsars are not the only objects that emit rhythmic pulses. Some binary systems that include black holes in orbit or neutron stars can emit periodic signals due to gravitational interactions or matter accretion. Additionally, regions in the galactic center are inhabited by objects that emit microsecond pulses and are studied in detail by astronomers.

Long-Period Transients

Pulsars emit pulses generally in a short time frame, in the order of microseconds. Meanwhile, LPTs (Long-Period Transients) are a class of astronomical objects that emit radio pulses on much longer time scales than traditional pulsars. These scales can range from a few minutes to even hours, setting them apart from the rapidly rotating pulsars. The exact nature of LPTs remains unknown.

Observing LPTs sometimes includes detecting pulses in both radio waves and other long-wavelength signals. This detection across different electromagnetic bands is interesting because it can indicate what kind of phenomenon is behind the LPTs. Studying LPTs even suggests a new type of object or still-unknown effect in the universe.

ASKAP J1832-0911

Recently, researchers used data from the ASKAP radio telescope in Australia to identify an object they named ASKAP J1832-0911. This object emits radio waves in an extremely regular pattern of about 44 minutes. Due to the long time between pulses, the group classified the object as a known LPT. However, astronomers compared it with data from the same region observed by NASA’s Chandra telescope.

Observation of ASKAP object in radio and X-rays by ASKAP and Chandra telescopes. Credit: Wang et al. 2025

By comparing the X-ray data from Chandra, they noticed that this same region emitted X-rays with the same 44-minute timing and repetition as observed by ASKAP in radio waves. This is extremely different from a typical LPT, which generally only emits in longer wavelengths like radio. No other LPT example had previously shown energetic signals coming from an LPT.

A New Type of Object?

Due to this feature of ASKAP J1832-0911—emitting both energetic and low-energy waves—it has caught astronomers' attention. This could suggest that other LPTs might emit in energetic wavelengths and that telescopes like Chandra could be used to search for these objects with longer pulses. Furthermore, this new understanding helps narrow down the list of possible sources, as the differences between radio and X-ray waves must be considered.

The discovery of this X-ray emission with a long interval offers new insights into the nature of LPTs. Currently, explanations for LPTs involving magnetars, binary systems, and white dwarfs fail to account for both high- and low-energy emissions. This could indicate a new type of object or phenomenon that we have yet to discover in the universe.

News Reference:

Detection of X-ray emission from a bright long-period radio transient. May 28, 2025. Wang, et al.