On the rarer side, some supernova explosions are likely to produce detectable gravitational waves. And since we don#8217;t know exactly how stars explode, LIGO and Virgo may be able to provide us with some valuable insight. Supernovae make a lot of light (like colliding pulsars), so we could again use multiple types of observations to study the same event.
Meanwhile, the field is just getting started. LIGO isn#8217;t operating at its maximum capabilities yet, and this year is the first time its two detectors have worked in tandem with Virgo. When all the observatory’s upgrades are done, we#8217;ll detect gravitational waves from farther distances, and catch fainter signals closer to home.
S. Ossokine/A. Buonanno/T. Dietrich (MPI for Gravitational Physics)/R. Haas (NCSA)/SXS project
A cosmic workaround
LIGO, Virgo, and the upcoming Japanese observatory KAGRA are massive as far as scientific instruments go. Each of LIGO#8217;s L-shaped detectors has arms 2.5 miles (4 kilometers) long, while Virgo#8217;s arms are nearly 2 miles (3 km) long. The arms must be long to ensure they’re sensitive to gravitational waves, which can have large wavelengths. LIGO, for example, is currently most sensitive to wavelengths between about 60 and 600 miles (100-1,000 km). Even so, many astronomical objects produce gravitational waves too big for the detectors to catch. This is because gravitational waves are often comparable to the physical size of their source.