For anyone not familiar with the language of telescopes, saying that the GTC will be the first telescope in the world with a 10.4 m diameter mirror will have little meaning. Explaining what it means is simple - the GTC will show us things that were previously impossible to observe: we will discover a part of dark matter, see the “birth” of the remotest galaxies and stars in the Universe and analyse their constituents, look in more detail at the characteristics of certain black holes and how they evolved, find out what chemical elements the Universe was made of just after the Big Bang... in brief, the GTC will give us vital information for advancing the study of celestial bodies, their past and their future, so that we can better understand where they came from and how they will evolve.
LET’S FIND OUT MORE ABOUT...
The Solar System:
Studying planetary phenomena is once again becoming very important as our understanding of the Solar System grows. In addition, new space missions require ever more demanding supporting observations. For example, to study the atmospheric dynamics of planets, narrow filter rapid photometry is needed to track phenomena from inside the atmosphere to the limb of the planet.
Extrasolar planets, substellar objects and faint stars:
In the 1990s exoplanets, planets that are outside the Solar System, were discovered for the first time. The challenge facing us is to discover planets that are similar in size to the Earth (the planets discovered up to now have been more like Jupiter, 11 times larger than the Earth). The same is true of brown dwarf stars, which have only been found relatively close to the sun; we now need to locate them at greater distances so that we can complete a galactic ‘census’. The situation is the same for cold white dwarfs, very faint stars that played a prominent part in the evolution of our galaxy’s halo, where some of the most ancient stars are to be found.
Protostellar objects and stellar formation:
New stars are formed deep inside cold, dense molecular clouds and so cannot be seen very well from the earth. To see them we need a telescope with a large light-collecting surface, excellent image quality in the optical and infrared spectra and a number of other features.
Compact objects and black holes:
Compact objects and black holes, which give off a lot of energy, are easily located using X- and gamma ray satellites, but large telescopes are needed to determine their mass.
Star populations in our galactic neighbourhood have yet to be studied - only the galaxies closest to the Milky Way have been examined up to now. There is also a lack of knowledge about the chemical abundances of the galaxies in our Local Group and about the distance scale.
Active galaxies, ultraluminous galaxies and primaeval galaxies:
The astronomical community is currently debating the origin of thermal and other types of active galaxies. Ultraluminous galaxies are equally enigmatic - they emit most of their energy in the infrared spectrum and are veritable hotbeds of new stars.
What chemical elements was the Universe composed of just after the Big Bang? More specifically, it is important that we find out how much helium was created, given the central role it has in testing the Big Bang nucleosynthesis theory. However it is not easy to determine the abundance of helium in the places where it is detectable - that is, in the HII regions of dwarf galaxies, whose spectra are very difficult to obtain. A parallel technique is that of detecting the lithium in the stars of our Galaxy’s halo. High quality spectra are also necessary for studying very distant objects, such as distant galaxies and quasars, which appear at high redshift because of the expansion of the Universe (Doppler Effect).
LINKS TO THE SCIENTIFIC PROGRAMS OF THE INSTRUMENTS: