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A unique celestial object, known as ASKAP J1832–0911, is capturing the attention of astronomers. Discovered 15,000 ly from Earth, this enigmatic object, located in our galaxy, behaves in a way never seen before. Identified thanks to the ASKAP radio telescope in Australia and NASA's Chandra X-ray telescope, ASKAP J1832 belongs to the class of long-period radio transients (LPTs), objects that vary in the intensity of their radio emissions on scales of tens of minutes. But ASKAP J1832 is not just any LPT! Its main characteristics are: - Synchronized pulsations. Every 44.2 minutes, ASKAP J1832 emits perfectly aligned radio and X-ray signals, a unique behavior. It is the first LPT in which an X-ray emission with the same period as radio waves is observed. - Extraordinary brightness. Its radio pulsations reach 10–20 Jy (radio flux units), making it one of the brightest LPTs ever observed. Its X-ray luminosity, measured at 7.4 × 10^32 erg/s, is equally impressive. - Extreme variations. Between February and August 2024, its luminosity plummeted: radio emissions decreased by a factor of 1,000 (from 10 Jy to 60 mJy) and X-rays dropped by at least a factor of 10, becoming undetectable. This variability is unprecedented! - Strong magnetic field. Its radio emissions show a high polarization (about 92%), suggesting a highly ordered magnetic field. The size of the emitting area, less than 150,000 km, indicates that it is a compact object, such as a neutron star or a white dwarf. Scientists are trying to figure out what ASKAP J1832 is, but no theory fully explains it: - An old magnetar? It could be a neutron star with a strong magnetic field (~10^13 G) and an age of over 500,000 years, but its ability to produce such bright radio signals defies current models. - A binary white dwarf? Its properties are reminiscent of systems like AR Sco, where a magnetized white dwarf interacts with a companion star. However, ASKAP J1832 would require a record magnetic field (>5 × 10^9 G), the strongest ever hypothesized for a white dwarf in our Milky Way. Excluding traditional pulsars (its luminosity is too high compared to its rotational energy) and isolated white dwarfs (the X-ray emissions are too intense and variable). ASKAP J1832–0911 is the first LPT with pulsed X-ray emissions, inaugurating a new category of periodic transients on an hourly scale. Its discovery challenges existing astrophysical theories and raises new questions: How can such an old object produce such intense signals? What mechanisms generate its synchronized and coherent emissions? Future observations will be crucial to confirm the nature of this object and discover whether it represents a prototype of a new class of celestial phenomena. Its location close to a supernova remnant (but probably unrelated) adds further mystery. The discovery of ASKAP J1832–0911 highlights the importance of multi-band observations (radio, X-ray, infrared) to identify and characterize other LPTs. Instruments such as ASKAP, Chandra, and the Very Long Baseline Array (VLBA) are essential to precisely locate and study these objects. ---------------------------------- Image: A wide field image of ASKAP J1832 in X-ray, radio, and infrared light. Credit: X-ray: NASA/CXC/ICRAR, Curtin Univ./Z. Wang et al.; Infrared: NASA/JPL/CalTech/IPAC; Radio: SARAO/MeerKAT; Image processing: NASA/CXC/SAO/N. Wolk Research Paper: "Detection of X-ray Emission from a Bright Long-Period Radio Transient"➡️https://t.co/MG2TOGqojN Press Release➡️https://t.co/jUDuTqhnqM

Nereide's tweet photo. A unique celestial object, known as ASKAP J1832–0911, is capturing the attention of astronomers.

Discovered 15,000 ly from Earth, this enigmatic object, located in our galaxy, behaves in a way never seen before.

Identified thanks to the ASKAP radio telescope in Australia and NASA's Chandra X-ray telescope, ASKAP J1832 belongs to the class of long-period radio transients (LPTs), objects that vary in the intensity of their radio emissions on scales of tens of minutes.

But ASKAP J1832 is not just any LPT!

Its main characteristics are:

- Synchronized pulsations.
Every 44.2 minutes, ASKAP J1832 emits perfectly aligned radio and X-ray signals, a unique behavior. It is the first LPT in which an X-ray emission with the same period as radio waves is observed.

- Extraordinary brightness.
Its radio pulsations reach 10–20 Jy (radio flux units), making it one of the brightest LPTs ever observed. Its X-ray luminosity, measured at 7.4 × 10^32 erg/s, is equally impressive.

- Extreme variations.
Between February and August 2024, its luminosity plummeted: radio emissions decreased by a factor of 1,000 (from 10 Jy to 60 mJy) and X-rays dropped by at least a factor of 10, becoming undetectable. This variability is unprecedented!

- Strong magnetic field.
Its radio emissions show a high polarization (about 92%), suggesting a highly ordered magnetic field. The size of the emitting area, less than 150,000 km, indicates that it is a compact object, such as a neutron star or a white dwarf.

Scientists are trying to figure out what ASKAP J1832 is, but no theory fully explains it:

- An old magnetar?
It could be a neutron star with a strong magnetic field (~10^13 G) and an age of over 500,000 years, but its ability to produce such bright radio signals defies current models.

- A binary white dwarf?
Its properties are reminiscent of systems like AR Sco, where a magnetized white dwarf interacts with a companion star. However, ASKAP J1832 would require a record magnetic field (>5 × 10^9 G), the strongest ever hypothesized for a white dwarf in our Milky Way.

Excluding traditional pulsars (its luminosity is too high compared to its rotational energy) and isolated white dwarfs (the X-ray emissions are too intense and variable).

ASKAP J1832–0911 is the first LPT with pulsed X-ray emissions, inaugurating a new category of periodic transients on an hourly scale. Its discovery challenges existing astrophysical theories and raises new questions: How can such an old object produce such intense signals? What mechanisms generate its synchronized and coherent emissions?

Future observations will be crucial to confirm the nature of this object and discover whether it represents a prototype of a new class of celestial phenomena.
Its location close to a supernova remnant (but probably unrelated) adds further mystery.

The discovery of ASKAP J1832–0911 highlights the importance of multi-band observations (radio, X-ray, infrared) to identify and characterize other LPTs. Instruments such as ASKAP, Chandra, and the Very Long Baseline Array (VLBA) are essential to precisely locate and study these objects.

----------------------------------

Image: A wide field image of ASKAP J1832 in X-ray, radio, and infrared light.

Credit: X-ray: NASA/CXC/ICRAR, Curtin Univ./Z. Wang et al.; Infrared: NASA/JPL/CalTech/IPAC; Radio: SARAO/MeerKAT; Image processing: NASA/CXC/SAO/N. Wolk

Research Paper: "Detection of X-ray Emission from a Bright Long-Period Radio Transient"➡️https://t.co/MG2TOGqojN

Press Release➡️https://t.co/jUDuTqhnqM

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