Tag Archives: dust disk

The Mysteries of Fomalhaut

At a distance of 25 Light-Years from Earth is a trinary star system that has been of much interest to scientists. There has also been a controversy regarding whether it hosts an exoplanet that has been called “Fomalhaut b.” This possible exoplanet has also been given the name of “Dagon” which was the name of one of the false gods of the Philistines in Old Testament times. In multiple star systems if a capital letter is used it refers to one of the stars but if a lower-case letter is used it refers to an exoplanet. Thus, to say “Fomalhaut B” refers to the second star but “Fomalhaut b” refers to the first exoplanet. Scientists never use a lower case “a” in reference to exoplanets. Fomalhaut A is the brightest star of the three and it has a very large dust disk around it. This disk has been imaged recently with the James Webb Space Telescope, revealing that there is much more to the disk than scientists expected. There are three separate rings in the Fomalhaut A disk, which spreads out for 150 Astronomical Units distance from the star. Fomalhaut C also has a disk, but it hasn’t generated as much interest apparently. Fomalhaut C is farther away but it orbits the center of gravity of Fomalhaut A and B. Fomalhaut A and B are just under one A.U. apart and they orbit around the common center of gravity between them. Fomalhaut B is also known as a flare star. It is variable and has very strong solar flares periodically.

The large disk around Fomalhaut A is an interesting study in what our scientific methods can and cannot tell us. In 2008 it was reported that using the Hubble Space Telescope, an object could be seen having moved in the disk between 2004 and 2006. It was believed to be an exoplanet and it was called Fomalhaut b. It was occassionally observed a few other times up to including 2012 and 2013 by various researchers. It was still considered an exoplanet at that time. In fact, in 2015 the IAU completed a contest for allowing people to submit names for exoplanets and other objects. The IAU adopted the name “Dagon” as the official name of exoplanet Fomalhaut b. However, in April 2020 a scientific paper was published arguing that the object called Fomalhaut b had disappeared and showed characteristics of it being a cloud from a collision instead of a planet. So it may have never been a real planet. The Fomalhaut A disk is enormous and probably very thick, so it could hide sizable objects. So there is currently a difference of opinion among scientists on the existence of Fomalhaut b. It can be a healthy thing for us fallible human beings to run into the limits of what we know so we have to deal with something that is uncertain or unclear. Time can clarify things, as we learn more. I do not mean to criticize scientists regarding either point of view on whether Fomalhaut b exists or not. I would lean for the moment toward the view that it was a cloud from a collision and not a planet. But we may have to wait and see what is discovered next.

The picture below diagrams the various rings found around Fomalhaut A. Such as disk is referred to as a “debri disk.” To understand the various comments from scientists on this, it is important to understand the difference between a “protoplanetary disk” and a “debri disk.” A protoplanetary disk has both gas and dust and these are not really observed, though whether there are actual examples might be considered debatable. A protoplanetary disk exists early in the process after the star has formed and planets and other asteroid-like objects may have not yet formed. The gas is believed to be key to the process of planet formation. The presence of the gas is believed to help planet migration happen and it provides gas for gaseous planets. But the gas dissipates or is absorbed by the star or the planets in less than 10 million years according to models. After the gas dissipates away then solid objects and planets may collide, generating dust. So at Fomalhaut, scientists would not expect planets to form from the disk that exists now. But they would expect there to be sizable objects there somewhere because in their view, some type of objects had to collide to generate the disk and its rings. The gaps in the rings are also thought to suggest there are objects that have “sculpted” the rings, forming the gaps. The James Webb telescope uses infrared and zeros in on three different frequencies of light which detects dust. Dust turns out to be rather bright in infrared, but macroscopic objects like asteroids or planets are dark and faint in infrared. At the present time, there is not clear evidence of either planets or asteroids in the Fomalhaut rings.

JWST Fomalhaut image
Fomalhaut A debri disk showing three belts. Source Space Telescope Science Institute.

In trying to take a biblical view of things, I would say we don’t know if God created planets at Fomalhaut or not. God could have created multiple dust rings with no planets or asteroids. The evidence at other stars with disks may be different as well. There is a tendancy in astronomy for scientists to assume a history of the system that we do not and cannot know for sure. Physics can give some insight on how a system may change over time or about the way objects interact. But physics does not necessarily tell us the initial conditions in the beginning. Computer simulations can give insight as well but there is always a limitation of a computer simulation. How can you be sure the simulation represents conditions like those in the real system? Scientists would like to see some confirmation of accepted theories of the formation of extra-solar systems. They would like to find evidence of asteroids or planets so there is an indication that collisions formed the dust rings at Fomalhaut. Fomalhaut’s third ring is about 150 A.U. in diameter; so, this would require multiple collisions of small bodies or a catastrophic collision of a large planet. The burning question raised to scientists is “where are the planets?”

Sometimes God seems to arrange events so as to go against human expectations and humble us as human beings. This brings up an account from the Old Testament book of 1 Samuel. It is ironic that Fomalhaut b was named “Dagon.” I don’t know who suggested this name or why it was proposed. Fomalhaut b appears to not be a real exoplanet and in the story in 1 Samuel, Dagon was shown to be a false god. So there is an ironic parallel in using the Dagon name for this exoplanet. To really get the whole story would require reading 1 Samuel chapters 2-7. But the key part for my purpose is mainly in chapter 5. In ancient Israel there was a priest named Eli who had two sons but his sons were sinful and when Israel’s leaders were corrupt things did not go well for the nation. The Israelite army attacked the Philistines and lost the battle. About 4,000 Israelite men were killed in that battle. So then the Israelites decided to go get the Ark of God (the Ark of the Covenant) and take it into battle. They treated it as if it were like a simple outward rule doing what God required, as if God did not know what they were really thinking. They thought that like in the past if they took the Ark into battle that they would win just because they had the Ark. But God taught them a costly lesson. They took the Ark into battle and the Philistines saw the Ark and were afraid because they had heard the stories of what had happened in the past when the Israelites defeated other armies while they had the Ark. But the power was never in the Ark itself, but in God himself being with them. In spite of their fear, the Philistines fought the Israelites. So in this particular situation, the Philistines, sinful and unbelieving though they were, were showing more awareness in some ways than the Israelites! So in the battle the Philistines won and the Israelites lost 30,000 men! Also, the Philistines took the Ark of God. The Philistines praised their god, Dagon, and they took the Ark of God and put it in the temple of Dagon.

The following morning the Philistines went to their temple and found that Dagon’s statue had fallen on its face in front of the Ark of God. So, the Philistines seemed to think little of it. They sat Dagon’s statue back in its place. Then the next morning when they went back to their temple, Dagon had fallen down again and this time its head and its hands were broken off. This was not a prank from the Israelites. After taking such a beating from the Philistines, no Israelite would have dared to do something like this in the Philistine temple. Then the Philistines seemed to debate for some time what to do with the Ark of God. First, they moved it out of the temple to another city called Gath. But after moving it the people of Gath broke out with tumors. So they moved it once again to the city of Ekron, and again in Ekron there was an outbreak of tumors and people were dying. Eventually, they sent it back to Israel on a cart pulled by two cows. Both the Israelites and the Philistines got lessons in taking God seriously. It is a sobering story.

I’m not saying the scientists looking for an exoplanet at Fomalhaut are like the Philistines (or like the Israelites for that matter). There is nothing wrong with searching for a planet at Fomalhaut. In science there may be different opinions from scientists as research continues. But there is something to say for having a bit of humility and realizing we don’t know everything. The Old Testament contains accounts of many amazing miracles God did in the past. The Old Testament also mentions known people groups, and places and events confirmed by historical evidence. But whether scientists theories are right or wrong, God ultimately gets the last word.