A Nebula that Extends its Hand into House

The Gum Nebula is an emission nebula nearly 1400 light-years away. It’s house to an object often called “God’s Hand” among the many devoted. The remainder of us name it CG 4.

Many objects in house tackle fascinating, ethereal shapes straight out of somebody’s psychedelic fantasy. CG4 is certainly ethereal and extraordinary, however it’s additionally a bit of extra prosaic. It appears like a hand extending into house.

The Darkish Vitality Digicam (DECam) on the NSF’s Víctor M. Blanco 4-meter Telescope captured the picture. DECam’s main job is to survey lots of of hundreds of thousands of galaxies in its examine of darkish power. But it surely’s additionally a general-purpose instrument used for different scientific endeavours.

CG 4 is named a cometary globule due to its look. But it surely’s truly a star-forming area. It has a head that’s about 1.5 light-years in diameter and a tail that’s about 8 light-years lengthy. The top is dense and opaque and is lit up by a close-by star. The globule is surrounded by a diffuse crimson glow, emissions from ionized hydrogen.

This excerpt shows a close-up of CG 4. The hand looks like it's about to grasp an edge-on spiral galaxy named ESO 257-19 (PGC 21338). But the galaxy is more than a hundred million light-years beyond CG 4. Only a chance alignment makes it seem close. Near the head of the cometary globule are two young stellar objects (YSOs). They're stars in their early stage of evolution before they become main-sequence stars. Image Credits: Credit: CTIO/NOIRLab/DOE/NSF/AURA
Image Processing: T.A. Rector (University of Alaska Anchorage/NSF's NOIRLab), D. de Martin & M. Zamani (NSF's NOIRLab) — This excerpt exhibits a close-up of CG 4. The hand appears prefer it’s about to understand an edge-on spiral galaxy named ESO 257-19 (PGC 21338). However the galaxy is greater than 100 million light-years past CG 4. Solely an opportunity alignment makes it appear shut. Close to the pinnacle of the cometary globule are two younger stellar objects (YSOs). They’re stars of their early stage of evolution earlier than they turn into main-sequence stars. Picture Credit: Credit score: CTIO/NOIRLab/DOE/NSF/AURA
Picture Processing: T.A. Rector (College of Alaska Anchorage/NSF’s NOIRLab), D. de Martin & M. Zamani (NSF’s NOIRLab)

There are many cometary globules within the Milky Approach. They’re a sub-class of objects known as Bok globules, after astronomer Bart Bok, who found them. Each sorts of globules are dark nebulae, molecular clouds so dense they block optical mild. Astronomers aren’t completely sure how cometary globules get their form.

However they do know what’s taking place to them.

The crimson glow surrounding CG 4 is ionized hydrogen lit up by radiation from close by sizzling, huge stars. That very same radiation is eroding CG 4 away. For the reason that globule is denser than its environment, it’s resisting diffusion. It nonetheless accommodates sufficient fuel and dirt to kind a number of new stars about as huge because the Solar.

In this zoom-in, the hand looks more like the mouth of the Shai-Hulud, reaching out into space to destroy the approaching Sardaukar. Image Credit: CTIO/NOIRLab/DOE/NSF/AURA. Image Processing: T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab), D. de Martin & M. Zamani (NSF’s NOIRLab) — On this zoom-in, the hand appears extra just like the mouth of the Shai-Hulud, reaching out into house to destroy the approaching Sardaukar. Picture Credit score: CTIO/NOIRLab/DOE/NSF/AURA. Picture Processing: T.A. Rector (College of Alaska Anchorage/NSF’s NOIRLab), D. de Martin & M. Zamani (NSF’s NOIRLab)

Though there are various of those globules within the Milky Approach, the vast majority of them are within the Gum Nebula. Scientists know of 31 different globules within the nebula. This one’s known as CG 4 (Cometary Globule 4) as a result of they’re all numbered.

This image shows three of the 32 CGs in the Gum Nebula: CG 30, 31, and 8. Image Credit: By Legacy Surveys / D.Lang (Perimeter Institute) & Meli Thev - Own work, CC BY 4.0, — This picture exhibits three of the 32 CGs within the Gum Nebula: CG 30, 31, and eight. Picture Credit score: By Legacy Surveys / D.Lang (Perimeter Institute) & Meli Thev – Personal work, CC BY 4.0,

The Gum Nebula is probably going the remnant of an enormous supernova explosion, and that may very well be the explanation the globules have their distinctive form. They could have initially been spherical nebula just like the Ring Nebula. However a robust supernova explosion about a million years in the past stretched them into their lengthy, comet-like kinds.

The James Webb Space Telescope captured this image of the Southern Ring Nebula, or NGC 3132, with its NIRCAM instrument. Cometary globules could've started out as ring-shaped nebulae before being deformed by supernova explosions. Image Credit: By Image: NASA/ESA/CSA/Space Telescope Science Institute. Public Domain — The James Webb House Telescope captured this picture of the Southern Ring Nebula, or NGC 3132, with its NIRCAM instrument. Cometary globules may’ve began out as ring-shaped nebulae earlier than being deformed by supernova explosions. Picture Credit score: By Picture: NASA/ESA/CSA/House Telescope Science Institute. Public Area

Astronomers additionally recommend one more reason for his or her form. Close by sizzling, huge stars exert radiation stress on the globules, and their stellar wind additionally slams into them. Within the Gum Nebula, their tails level away from the Vela Supernova Remnant and the pulsar that sits in its centre. For the reason that Vela Pulsar is a spinning neutron star, it’s attainable that its winds and radiation stress are shaping CG 4.

No matter its trigger, the Hand of God is a visually intriguing object. In case you actually wish to lose your self on this superb nebula, obtain the TIFF file here.