Spacetime ripples may be shaken in a way that astronomers have never seen in debris cocoons surrounding fading stars.
Astrophysicist Ore Gottlieb from Northwestern University in Evanston, Illinois, revealed on June 5 at the American Astronomical Society gathering in Albuquerque that this unexplored phenomenon holds promising implications as a gravitational wave origin.
In the most recent LIGO run, which got under way on May 24, the waves might be detected.
All of the gravitational waves observed so far since LIGO's initial detection in 2015 have come from the swirling death dance of the two - either black holes, neutron stars, or both (SN: 2/11/16). They produce gravitational waves that are referred to as coherent. Gottlieb said that it could be compared to the harmonies of an orchestra.
Another category, known as incoherent waves, is anticipated to emanate from stellar explosions such as supernovas (SN: 5/6/19). Due to their spherical symmetry and relatively gradual nature, detecting these waves poses challenges for LIGO. One can liken them to a simultaneous performance by multiple instruments and they play different melodies.
Another kind of star death that Gottlieb and colleagues took into consideration was a collapsar. Jets of material moving nearly at the speed of light can be released when big stars merge into black holes. According to Gottlieb, who presented the findings on June 6 at a meeting of the American Astronomical Society, computer simulations illustrating the formation of these jets unveiled a cocoon enveloping the jet itself. This cocoon consists of a mixture of scorching turbulent gas and debris that expands unevenly, creating an asymmetrical bubble around the dying star.
According to Gottlieb and colleagues, as the bubble enlarges and pushes through the star, it may cause enough spacetime to be bumped, resulting in the production of incoherent gravitational waves.
There is currently a 1% possibility that LIGO and its companion detectors, Virgo in Italy and KAGRA in Japan, may find cocoon gravitational waves. That likelihood will rise in subsequent runs with more advanced detectors.
Astronomers may be able to study dying stars' deepest regions, which are inaccessible in any other manner, if they can catch these waves, according to Gottlieb.