Astronomers have recently stumbled upon a perplexing cosmic phenomenon – an ultra-slow, long-lasting source of radio-wave pulses, unlike any known astrophysical object. While typical radio pulsars emit brief pulses at incredibly short intervals, this enigmatic source has been regularly emitting pulses every 22 minutes since 1988, leaving scientists intrigued and baffled. In this article, we delve into the discovery of this peculiar celestial entity, its unusual characteristics, and the diverse theories proposed to explain its nature.
The discovery of this mysterious source was made possible by observations from the Murchison Widefield Array (MWA) observatory in Western Australia. Known as GPM J1839-10, the source is located approximately 18,500 light-years away in the constellation Scutum. Detailed follow-up observations were carried out using various radio observatories in Australia and South Africa, providing crucial data about its behavior and characteristics.
Challenging the Traditional Pulsar Model
Traditionally, pulsars, which are magnetized neutron stars, emit beams of particles and radiation from their magnetic poles due to their rapid rotation. However, the enigmatic GPM J1839-10 challenges this conventional explanation. Its slow rotation rate raises questions about the generation of energetic beams and the pulsar model’s viability. Astronomers have been perplexed as to how such a slow-spinning neutron star could emit pulses of radio waves at all.
To understand this celestial enigma, researchers propose alternative scenarios, one of which involves a strongly magnetized and isolated white dwarf star. Unlike neutron stars, magnetized white dwarfs with larger mass might still be capable of generating beams of energetic particles despite a relatively slow rotation rate. However, this explanation also faces challenges as no nearby, isolated white dwarfs have exhibited such bright radio emissions, let alone in the form of pulses.
Investigating the Possibilities
While some researchers lean towards the white dwarf model due to its testable nature, others are not willing to discard the classical pulsar explanation just yet. The rich physics of radio pulsar magnetospheres and the potential for modifications in nature leave room for multiple possibilities. To provide further insights, deep observations at visible and infrared wavelengths with advanced telescopes, such as the James Webb Space Telescope, are proposed to reveal a potential counterpart at these wavelengths.
The discovery of GPM J1839-10, the mysterious, slowly pulsing star, has opened up a realm of possibilities and raised intriguing questions about the nature of astrophysical sources. Astronomers remain captivated by this celestial enigma, and ongoing research and observations promise to shed light on the true identity and behavior of this enigmatic cosmic phenomenon. As we continue to unravel the secrets of the universe, nature’s ingenuity and complexity serve as a constant reminder of the vastness of the cosmos that awaits exploration.
Story Courtesy: Sky & Telescope