‘God’s Hand’ Interstellar Cloud: Dark Energy Camera Detects Cometary Globule Reaching for the Stars

New images of a distant nebula have revealed what looks like a gargantuan hand made of gas and dust reaching out into the cosmos.

Ghostly Cosmic Hand

Astronomers have detected a ghostly structure stretching from a distant edge-on spiral galaxy. Despite its nickname, " this cloudy, ominous formation does not have anything supernatural.

God's Hand is actually a cometary globule located around 1,300 light years from Earth in the constellation Puppis. Officially known as CG 4, the structure has a distinctive tail made of an eight-light-year-long tendril of dust and gas with a tip about 1.5 light-years wide.

CG 4's tail is apparent in the Dark Energy Camera (DECam) images, a tool located on the Victor M. Blanco 4-meter Telescope. This telescope is kept at Cerro Tololo Inter-American Observatory, located at an altitude of 7,200 feet (2,200 meters) above Chile.

To see through the stellar dust, the DECam is outfitted with a Hydrogen-alpha filter, which allows the instrument to image ionized hydrogen. In the case of the God's Hand globule, this structure appears as a red glow with its claw and its outlining edge.

In the DECam image, the lobster-claw-like head of God's Hand appears to be reaching out for the spiral galaxy ESO 257-19 (PGC 21338), which is seen edge-on from our perspective here on Earth. While the galaxy may look like it is gripped by CG 4, it is actually safe from harm as it is located about 100 million light years away from the cometary globule.

Even if ESO 257-19 happened to be closer to CG 4, it would still be safe from its reach since the same radiation that ionizes the hydrogen in the 'Hand' is also disintegrating its structure. Despite this fact, there is still enough dust and gas within God's Hand to create several new sun-sized stars.

What Are Cometary Globules?

Cometary globules are faint, small clouds of dust and gas found within the Milky Way galaxy. They are a hard-to-detect subclass of Bok globules, the dense and isolated clouds of gas and dust surrounded by hot, ionized material.

Despite their name, cometary globules are not related to comets. The moniker comes from the fact that as nebulas contain material dragged away from them, the event creates a long tail that resembles a comet's tail.

For many years, cometary globules have remained mysterious because the origin of their structure has not yet been fully determined. Astronomers assume that the structure of cometary globules could be created either by stellar winds that flow from the hot, massive stars surrounding them or from the supernova explosion that occurs when these stars die.

The ionized hydrogen in cometary globules is formed when this element is bombarded by intense radiation coming from nearby mass stars. As a result, the electrons are stripped, eventually ionizing the gas.

Bok clusters were not discovered by scientists until the mid-1970s. Their detection was evaded for so long because of their faintness, as well as the fact that their tails are covered by stellar dust, which prevents light from passing through it. While most of them are found throughout the Milky Way galaxy, the majority of them are found within the Gum Nebula, a huge cloud of gas thought to be the expanding remains of a massive star that died in a supernova explosion a million years ago.