Just in time for Halloween the shape of the Boomerang Nebula has finally been resolved - and it looks just like a ghost! Scientists using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope were able to study the nebula to learn more about its unique properties.
Previous studies from telescopes on land had misinterpreted the shape as being crooked, hence the name "Boomerang Nebula". Information from the Hubble Space Telescope indicated that the boomerang shape was wrong, but it was also incorrect in hinting that it was more like an hourglass. ALMA was able to more thoroughly analyze the nebula, and the data has revealed that the true shape looks a lot like a haunting ghost-like figure.
Aside from the spooky shape, Boomerang is unique in that it is thought to be the coldest place in the entire Universe. The nebula is a brisk 1 Kelvin (-480 °F, -272 °C), which is even colder than the afterglow of the Big Bang, which causes the natural background temperature of space. This nebula is in the constellation Centaurus, approximately 5,000 light years away.
Planetary nebulae acquire bright colors and odd shapes from the white dwarf star in its epicenter that has shed the outer layers and emits strong ultraviolet light. In the case of Boomerang Nebula, it is classified as pre-planetary, as the central star is not able to emit the UV light.
ALMA’s research will give never-before-seen insight into the death cycle of stars as they transition to planetary nebulae. It also allows us to monitor other stars in various stages of death that are similar to our own sun.
Preliminary data has shown that while the nebula is the coldest thing we’ve ever discovered, the edges are beginning to warm up. This could be due to an effect first theorized by Albert Einstein called the photoelectric effect. Under this law, matter absorbs energy light and emits photoelectrons. Work with photoelectrons earned Einstein the 1921 Nobel prize in Physics.