28 December 2016 Current Affairs: Pioneering astronomer Vera Rubin passed away on 25 December 2016. She was 88.
Rubin, who helped discover evidence of dark matter, passed away due to natural causes.
Vera Rubin : Born on 23 July 1928, Vera Rubin was an American astronomer.She pioneered work on galaxy rotation rates.
She studied galactic rotation curves and exposed the discrepancy between the predicted angular motion of galaxies and the observed motion. This phenomenon came to be known as the galaxy rotation problem.
Her results, which initially met with scepticism, were confirmed over the subsequent years. The attempts to explain the galaxy rotation problem led to the theory of dark matter.
Dark matter is an unidentified type of matter.It is distinct from dark energy, baryonic matter and neutrinos.Dark matter encompasses around 27 per cent of the mass and energy in the observable universe.
It does not emit or interact with electromagnetic radiation, like light. Therefore, it is invisible to the entire electromagnetic spectrum.
The existence and properties of dark matter are inferred from its gravitational effects such as the motions of visible matter, its influence on the universe's large-scale structure, gravitational lensing, etc.
It is transparent to electromagnetic radiation. It is so dense and small that it fails to absorb or release enough radiation to be detectable with current imaging technology.
The standard model of cosmology outlines that the total mass-energy of the universe contains 4.9 per cent ordinary matter, 26.8 per cent dark matter and 68.3 per cent dark energy.
One of the most widely accepted assumptions on the form for dark matter is that it is composed of Weakly Interacting Massive Particles that interact only through gravity and the weak force.
A group of astronomers reported in August 2016 that Dragonfly 44, an ultra diffuse galaxy with the mass of the Milky Way galaxy, but with almost no discernable stars or galactic structure, may be made almost entirely of dark matter.