We start our new year with a rather strange star (the name itself is rather strange). Those of you who like tongue twisters, may have your go at pronouncing its name. Its called Przybylski’s star. Go on, try it.
If you succeeded then you are a superhuman, if not, you are normal. Let us make things easier for ourselves. The name is pronounced as shi-bill-skee’s star. Well, thats easy. However, it is not the name we are interested in but, the nature of the star itself. The star was discovered by Polish astronomer Anton Przybylski in the year 1961.
He observed that the spectrum of the star did not match with the general framework of stellar classification. In other words, this star had elements heavier than iron like plutonium and other ultra heavy elements. Now a layman wouldn’t find that very strange but a brief understanding of the fusion processes in stars will make him/her understand the big deal.
A brief recap on stellar fusion.
First we ask, what is a star? A star is a ball of hydrogen and helium which undergoes nuclear fusion of lighter elements to heavier elements. Most stars, for a major part of their lives fuse hydrogen atoms to helium atoms. This process releases a lot of heat and light energy, hence supports the star. This is the main reason why our Sun glows and gives out heat and light.
The process of fusion is given below. Please note that Deuterium and Tritium are just two different isotopes of hydrogen.
Now, after the hydrogen supply runs out, i.e. all the hydrogen has been fused to helium, the future of the star depends on its mass.
For stars like our Sun, the outer layers begin to expand and they turn into a red giant. The red giant stage lasts for a few million years before the star shed its layers and turns into a white dwarf.
However, stars much more massive than the Sun continue fusing helium to carbon and carbon to oxygen. As this happens, the star swells up into a red supergiant. These stars meet their fate when the last atoms are fused to iron.
Iron is a very stable element which does not fuse easily into heavier elements. With no fusion energy to support it, the star collapses in on itself and dies in a spectacular explosion called a supernova. Here lies our key to understanding the strangeness of Przybylski’s star.
Plutonium in Przybylski’s star?
If you know a little bit of chemistry, then you might already have understood why this star is so mysterious. If not, no problem. A look at the periodic table, might tell you that plutonium is a much heavier element than iron.
Now we know that no elements heavier than iron can form in the star. But that is exactly what is happening here. Przybylski’s star contains plutonium and other ultra heavy elements which just cannot occur in the process of stellar fusion. Although plutonium does occur in Nature, stellar fusion is not the cause behind it.
However there still other actinide or trans-uraniam elements whose presence in the star have no explanation whatsoever. For the layman, there exist ultra heavy elements in this star which are extremely rare in Nature. These include americium, curium, berkelium (only 1 gram of that element has been ever synthesised on Earth), californium and einsteinium!!
Also noted, was the presence of technetium which is radioactive and does not exist as a stable atom. This maybe related to the presence of promethium and uranium which are also radioactive in nature. In fact this star has more praseodymium than iron!!
These elements exist on the bottom of the periodic table. A region about which we have very little knowledge about. Moreover these elements have been extremely rarely or never been seen in Nature which adds to the mystery.
So how did it get there? We don’t know! That is the mystery. But there are theories of course. What is science without the theories? The three most prominent ones are:
- This is all a mistake. There are always errors in astronomy from time to time and there is no compelling evidence that this one is not. Maybe there were some errors in the measurements of the spectrum of the star which showed the presence of plutonium. However, further observations will tell us for sure whether this is the case.
- There are new undiscovered processes that take place in a star. It is entirely possible that we have not understood stellar dynamics very well and there is a lot to learn. One possibility suggests that these elements have something to do with the star’s rather strange magnetic field. After all, the study of the Universe has shown us that all sorts of weird thing can occur in space that chucks common sense out of the window.
- What we are seeing are the waste products of alien industries!! As outlandish as that sounds, its entirely possible that alien nuclear industries discard their waste products into their parent star to prevent contamination of their home planet by radioactive materials.
Other theories suggest that the elements may have come from a nearby neutron star or a supernova. The problem is, there is no neutron star in the vicinity of Przybylski’s star that we know of. Moreover if the supernova holds true then there should also be plenty of iron and a supernova remnant, both of which are absent.
But if the alien hypothesis holds true, it would be the biggest breakthrough in science, which would be the detection of alien life. But before we jump at it, we need to rule out the other two possibilities which seem equally likely as the third one.
The problem with the alien theory is, only nuclear fission industries produce radioactive waste and aliens having the technology to dump waste into their star would upgrade themselves to nuclear fusion and not depend on nuclear fission for energy.
But one might argue that dumping these elements into the star maybe a civilisation’s way of showing their presence to other astronomers who might be studying the spectra of star’s (like Anton Przybylski). This is certainly better than wasting energy on sending radio signals as we do.
Yet, a good scientist must always consider all theories and rule out the unnecessary by subsequent observations. But the theory of aliens is an interesting one and if it holds true, it will certainly be a story to be remembered for ages to come.
Here is a video on the same topic, and it is the primary source for this information. Please check it out.