ORCs in space? Scientists find mysterious objects in the sky

Scientists working on a project known as the Evolutionary Map of the Universe (EMU) found three mysterious objects in space whose origin and nature is unknown. A fourth similar object was discovered in ancient data collected by the Giant MetreWave Radio Telescope in India.

The objects were named ORCs (Odd Radio Circles, or “Strange Radio Circles”), as they are highly circular. They have more intense brightness near the edge and are visible only at radio wave frequencies. Scientists have not yet been able to determine how far away they are, but they know they are outside the Milky Way’s galactic plane and are about 1 arc-minute in diameter. For comparison, the diameter of the Moon in the sky is 31 arcminutes.

Among other possibilities, astronomers speculate that the objects may be shock waves resulting from some extragalactic event, or activity coming from radiogalaxy, a type of galaxy that exhibits an intense wave emission in the radio band of the electromagnetic spectrum.

Kristine Spekkens, an astronomer at the Royal Military College and Queen’s University, both in Canada, speculates that objects may be a new phenomenon that has not yet been studied, or else an extension of some phenomenon already known, but that has not yet been fully explored.

All four ORCs are very bright at radio frequencies, but invisible in visible, infrared or x-ray light. Two of them have galaxies that emit visible light at their center, which suggests that they may have been formed by them. Two others appear next, which may indicate that they have a common origin.

With only four objects found so far, scientists cannot yet determine the nature of ORCs. However, the EMU project, which uses the Australian Square Kilometer Array Pathfinder (ASKAP), a set of 36 radio telescopes in Australia, can help us with the task. Scientists expect it to find about 70 million new objects emitting radio signals, almost 30 times more than the 2.5 million currently known.

Source: Live Science