'Molecules that absorbs starlight in space has been found'

Whale galaxy

“Which molecule is responsible for the absorption of starlight in space”? A question which has been dwelling in minds of many astrophysicists for about a century now has finally been given an answer. In this article, I am going to discuss about this flabbergast molecule which the scientists have been failed to discover until the mid-80s and it was not till 2015, that the theory was finally prove.

So, before even starting this discussion, let me brief you on the definition of starlight, which as the name suggests is the lights being emitted from the stars. It is an electromagnetic radiation which is quite observable from the surface of the earth during night-time. Some component of starlight can even be seen during daytime but that’s highly rare as because the color of a starlight is yellowish-white (similar to that of the sun rays) due to which the color merges with the rays of sun making it invisible for human eyes to differentiate.

Scientist at the University of Basel have been able to identify for the first time in a century a molecule that is indeed responsible for the absorption of starlight in the space, the positively charged cage-fused structure buckminsterfullerene, or so-called ‘football molecule’ (its structure is similar to that of a soccer ball). Buckminsterfullerene is a structure of 20 hexagons and 12 pentagons consisting of 60 carbon atoms, each placed at the vertex of each polygon.

From centuries ago, Astronomers have discovered that the spectrum of star lights arrived on earth with dark gaps, known as interstellar bands but they have not been successful until now to find out which matter in space is absorbing this starlight and causing the “diffused interstellar bands (DIB)”. There are over 400 known starlight in the outer-space today, each having different kind of mystic gaseous shape.

Astronomers have been suspecting that a big complex molecules and gaseous ions based on carbon could be absorbing the starlight. And no molecule other than Buckminsterfullerene matched their criteria which is so far the largest molecule in chemistry to show the property of a wave-particle duality.

Once the Buckminsterfullerene molecule was discovered in the mid-80’s, questions started arousing regarding buckminsterfullerene’s impact on the Dark Interstellar bands (DIB). Researchers started all kind of experiment in order to prove this theoretical aspect into practical reality and finally giving answers to these complicated questions. The experiments didn’t disappointed much as the spectrum measured in the lab did show absorption features at two wavelength that were near two DIB that had been discovered by the astronomers the following year.

Experimental Procedure of the research.

In order to unambiguously prove that these molecules (buckminsterfullerene) absorb starlight and thus produce the DIB, a gas phase spectrum of the ion was needed. To obtain the spectrum in the laboratory using a diode laser, several thousand Fullerenes were confined in a radio-frequency trap and cooled down by collision with high density helium to a very low temperature of around 6 degree Kelvin (conditions were very similar to that of outer space).

Triangulum Galaxy

After the results came out of this experimental research, the resultant absorption measured in the laboratory was coinciding with most of the astronomical data, and have a comparable bandwidths as well as relative intensities. This identifies for the first time two DIB and proves that ionized buckminsterfullerene in the gas-phase in space.

The experiment has helped solving one of the most critical problems in the field of astronomy and has further enhanced the advancing theory of cosmology. The whole research work was carried out at the Department of Chemistry, University of Basel.