HARPS-N (High Accuracy Radial velocity Planet Searcher for the Northern emisphere) is a high-precision spectrograph installed on the Telescopio Nazionale Galileo (TNG), located at the Roque de Los Muchachos Observatory in the Canary Islands.

A spectrograph is a spectroscope (an instrument used in chemistry and physics for the observation and analysis of electromagnetic radiation) that separates light into a spectrum according to frequency, mostly used in astronomy.

The main goal of HARPS-N, a collaboration between the National Institute for Astrophysics (INAF), the Astronomical Observatory of the University of Geneva, the Center for Astrophysics (CfA) of Cambridge (Massachusetts), the University of St Andrews, the University of Edinburgh and Queen’s University Belfast, is the discovery and characterization of exoplanets, based on the principle of the radial velocity variation of a star subject to gravitational forces of bodies rotating around it.

Temporarily putting to one side its mission, in late January the HARPS-N spectrograph succeeded in measuring from the Earth the velocity of the clouds in the atmosphere of Venus thanks to its high precision, competing with the Japanese Akatsuki probe, which has recently begun to study the atmosphere of the second planet.

“We love all challenges at the limit of the possibilities of our telescope. This one was a bit beyond, but we did it”, Emilio Molinari, Director of the TNG.

The atmosphere of Venus is in a state of super-rotation, spinning about 60 times faster than the solid globe”, explained Pedro Machado, researcher at the Institute of Astrophysics and Space Sciences in Lisbon, who led the observations. “The processes that induce and maintain this state are still a mystery, and our objective is to study the dynamics of the wind on Venus, its spatial and temporal variability, and detect and characterize the atmospheric gravity waves. Since the atmosphere of Venus contains large amounts of carbon dioxide, these studies will help us to better understand, and predict, Earth’s climate change. Moreover, Venus can be considered as a testing ground for the atmospheric characterization of exoplanets”.

Although this mode of use of the telescope and HARPS-N is not yet available to users because the team of researchers is still developing it, in the future it will be possible to choose the point to be observed even on extended objects such as Venus in this case, or on approaching comets or other planets of the Solar System.

Source: ResearchItaly