Comet C/2020 F8(SWAN) currently crossing our skies is expected to be visible by late May or early June. While its discovery by Amateur Astronomer Michael Mattiazo (Australia) gives us a perk to observe the night sky. The Solar Wind ANisotropies (SWAN) is an instrument used to map changes in the solar wind precisely the variable flow of charged particles onto the interplanetary space. SWAN usually captures images in UV. And this wavelength is predominant in emission by hydrogen atoms. For a comet, hydrogen is released from the water vapour the icy core releases when heated by the sun. Thus SWAN has become an effectual measure to discover comets since they are sources of hydrogen. Hydrogen clouds surrounding the Comet appears as a bright spot of Lyman-Alpha light which can be spotted by SWAN.
SWAN maps the night sky almost every day and records them. Comets can arrive from any direction almost instantly making it difficult to track them. Due to which the maps are subtracted from one another, removing stars, making moving or variable sources visible. These images are posted online on the SOHO website making them easily accessible to internet users. Retrieving these data, Mattiazo analysed the SWAN maps from early April 2020. After the discovery Michael Combi (University of Michigan) approximated the ejection of water molecules and it was estimated to be 1300 kg of water vapour per second.“This is already three times more than Comet 67P/Churyumov-Gerasimenko at its best, when it was visited by ESA’s Rosetta mission between 2014 and 2016,” said Jean-Loup Bertaux, former principal investigator and proposer of the SWAN instrument.
Currently, the Comet is faintly visible to the naked eye. Probably if the comet ejects more material, it can reflect more sunlight making it more visible. It is expected that by the end of May the Comet would become brighter and approaches its closest point to the Sun. But the Comets behaviour is unpredictable while making such a close trajectory. If nothing goes wrong stargazers could observe the Comet near the bright star Capella in the constellation of Auriga.
-SERIN MARY BINOY
Reference: NASA, ESA
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