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| 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).
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| 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.
