Astronomers have serendipitously identified a novel type of stellar explosion, termed ‘millinovas,’ which are approximately 100 times brighter than our sun. These events are believed to occur when a white dwarf star siphons material from a companion star, leading to a distinctive outburst.
Key Points at a Glance:
- New Phenomenon: ‘Millinovas’ represent a previously unrecognized class of stellar explosions.
- Discovery Context: Identified during a search for primordial black holes using data from the Optical Gravitational Lensing Experiment (OGLE).
- Characteristics: Exhibit symmetrical, triangle-shaped outbursts distinct from known variable stars.
- Occurrence: Detected in the Large and Small Magellanic Clouds, satellite galaxies of the Milky Way.
In a fortuitous discovery, astronomers have identified a new class of stellar explosions, dubbed ‘millinovas,’ which shine with a luminosity about 100 times that of the sun. These events were uncovered while researchers were analyzing two decades of data from the Optical Gravitational Lensing Experiment (OGLE), initially in search of gravitational microlensing events that could indicate the presence of primordial black holes in the Milky Way’s dark matter halo.
The team observed 28 such outbursts in the Large and Small Magellanic Clouds, neighboring galaxies to the Milky Way. The light curves of these events displayed a distinctive symmetrical, triangle-shaped pattern, setting them apart from previously known variable stars. This unique signature led researchers to classify them as a new type of stellar explosion.
The prevailing hypothesis suggests that millinovas occur when a white dwarf star accretes material from an expanded companion star. This process leads to a buildup of material on the white dwarf’s surface, eventually triggering a thermonuclear explosion responsible for the observed outburst. However, the exact mechanisms producing the X-ray emissions associated with these events remain unclear, prompting further investigation.
This discovery not only enriches our understanding of stellar evolution and the diverse phenomena associated with binary star systems but also underscores the value of extensive observational data in uncovering unexpected cosmic events. Future research aims to elucidate the underlying processes driving millinovas and to determine their frequency and impact within the broader context of galactic dynamics.
