Two new pulsars detected in globular cluster NGC 6522

By Ehtesham

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The cosmos, with its vast expanse, never ceases to surprise us with its celestial wonders. In the realm of astronomy, the MeerKAT radio telescope has once again illuminated the cosmic stage, revealing a spectacular discovery within the Galactic globular cluster NGC 6522.

Join us as we embark on a journey to unveil the unveiling of two new isolated pulsars within this ancient celestial congregation.

Cosmic Cradle

Pulsars, those enigmatic celestial entities, are highly magnetized, rapidly rotating neutron stars that emanate beams of electromagnetic radiation. To catch a glimpse of these cosmic lighthouses, astronomers often turn their telescopes toward globular clusters (GCs).

These clusters, bound together by gravity, serve as cosmic nurseries for a diverse array of astronomical objects. NGC 6522, a core-collapsed Galactic GC, emerged as the canvas for this celestial exploration.


A team of astronomers, spearheaded by Federico Abbate from the Max Planck Institute for Radio Astronomy in Bonn, Germany, embarked on a quest to unearth new pulsars within NGC 6522.

This endeavor was part of the MeerTIME and TRansients And PUlsars with MeerKAT (TRAPUM) projects, which employ the remarkable capabilities of the MeerKAT radio telescope.

NGC 6522 stands as a celestial gem, nestled at a distance of approximately 25,100 light years from our vantage point. With a colossal mass of about 300,000 times that of our Sun and an estimated age of 12 billion years, it potentially claims the title of the oldest star cluster in our Milky Way galaxy.

New Pulsars Emerge

In their cosmic odyssey, the team’s diligent observations yielded the discovery of two new isolated pulsars within NGC 6522. These celestial denizens, designated as PSR J1803−3002E and PSR J1803−3002F, enrich the celestial tapestry of this ancient cluster.

With these newcomers, the total count of known pulsars within NGC 6522 reaches six, and all of them stand as isolated entities.

PSR J1803−3002E: This is a mildly recycled millisecond pulsar (MSP) characterized by a spin period of approximately 17.9 milliseconds. It graces the central region of NGC 6522, contributing to the dynamic celestial landscape. Its dispersion measure, a parameter in radio astronomy, was measured at approximately 192.8 pc/cm3.

PSR J1803−3002F: In contrast, this pulsar exhibits a more leisurely spin with a period of about 148.1 milliseconds. It resides at a distance roughly equivalent to three core radii from the cluster’s center. Its dispersion measure was estimated at 195.8 pc/cm3.

An intriguing aspect of this discovery lies in the spin periods of these newfound pulsars, which exceed those of their predecessors. Additionally, the characteristic age of PSR J1803−3002F may be younger than the age of NGC 6522 itself, adding a layer of complexity to their cosmic narrative.

Enigmatic Age

Delving deeper into the celestial fabric, the study uncovered a tantalizing clue within the realm of NGC 6522. One of the millisecond pulsars, christened PSR J1803−3002C, displayed a characteristic age of a mere 132 million years.

This revelation, if confirmed, positions this pulsar among those with the smallest characteristic ages in the realm of globular clusters.

Cluster Development

The presence of both a slow pulsar and a seemingly young MSP, phenomena seldom witnessed in GCs, raises intriguing questions about their formation. Could their existence be intimately connected to the evolutionary stage of NGC 6522?

The authors of this remarkable study conclude with this question, hinting at the possibility that the cosmic tapestry weaves a narrative where the birth of pulsars intertwines with the cluster’s journey through time.


In the heart of NGC 6522, MeerKAT has unveiled two new pulsars, enriching our understanding of the universe’s celestial wonders. These cosmic sentinels, with their unique characteristics, beckon us to delve deeper into the cosmic cradle of this ancient cluster.

As we peer into the cosmos, we are reminded that the universe is a treasure trove of mysteries, waiting to be discovered by the inquisitive minds of astronomers.


What are pulsars, and why are astronomers interested in them?

Pulsars are highly magnetized, rapidly rotating neutron stars that emit beams of electromagnetic radiation. Astronomers study pulsars to understand various aspects of celestial objects and phenomena.

Why do astronomers focus on globular clusters like NGC 6522 to search for pulsars?

Globular clusters serve as ideal environments for the formation of various astronomical objects, making them hotspots for pulsar discoveries.

What is the significance of the discovery of two new pulsars in NGC 6522?

This discovery expands our knowledge of the celestial inhabitants of NGC 6522 and provides insights into the unique characteristics of these pulsars.

Why are the spin periods of the newly detected pulsars in NGC 6522 noteworthy?

The spin periods of these pulsars are longer than those of previously known pulsars in the cluster, raising questions about their formation and evolution.

How does the age of pulsars like PSR J1803−3002C relate to the age of NGC 6522?

The characteristic age of PSR J1803−3002C is remarkably small compared to the age of NGC 6522, suggesting an intriguing link between pulsar formation and the cluster’s evolutionary stage.