Point Sources

16 Jul 2020

Over the past ten years a number of studies have detected what is thought to be an excess of gamma ray radiation at the centre of our galaxy, the Milky Way. The source and the reasons why are unknown. Various explanations have been offered, which include dark matter annihilation, or a population of 'point sources' (sources of energy). It seems it is now being suggested we have a new kind of cosmic object - dim point sources. A new phenomenon in which to hang the excess gamma ray radiation. Hey presto ! Excess disappears, Equilibrium resurrected. See https://phys.org/news/2020-07-dim-sources-galactic-center-excess.html

A more tangible point source concerns Comet Atlas - which recently broke up as it approached the sun - see https://phys.org/news/2020-07-astrophysicists-carbon-comet-atlas-reveal.... ... astrophysicists suggest the amount of carbon found in Comet Atlas may help to reveal the ages of comets. Rather, the time they have spent orbiting in the inner solar system. The less carbon the longer they have been in the vicinity of the sun. An inordinately simple way to date comets, one might imagine. Comet Atlas, however, has a very high level of carbonaceous content. It was analysed as it streamed away from the comet. Comet Atlas, they say, was a long period comet. It entered the inner solar system once in every 5476 years. How they arrived at that figure is unclear but the point they are making is that previously, it only ocassionally orbited around the sun. It is assumed the heat of the sun caused the comet to disintegrate rather than a brush with the solar wind. Under the influence of solar radiation (therefore not necessary down to heat) the primordial matter on the comet evaporates, we are told. It is the evaporation of matter, whether by heat or solar radiation, that allows astronomers to study its composition - as gases and dust stream away into space. Comet Atlas would appear to be a close match to Comet Hale Bopp (1995) and Comet Hyatake (1996). See the Notices of the Royal Astronomical Society - at htttps://doi.org/10.1093/mnras/staa1725