Astronomía

THE ASTRONOMY
Astronomy is the science that
deals with the study of the
celestial bodies of the
universe, including the
planets and their satellites,
comets and meteors, stars and
interstellar matter, the
systems of dark matter, stars,
gas and dust called galaxies
and clusters of galaxies; by
what he studies their
movements and the
phenomena linked to them. His recording and investigation of its origin come
from the information that comes from them through the electromagnetic
radiation or any other means. Astronomy has been linked to human beings since
antiquity and all civilizations have had contact with this science. Characters
such as Aristotle, Thales of Miletus, Anaxagoras, Aristarchus of Samos,
Hiparco of Nicea, Claudius Ptolemy, Hypatia of Alexandria, Nicolas
Copernicus, Tycho Brahe, Johannes Kepler, Galileo Galilei, Christiaan
Huygens or Edmund Halley's Comet have been some of the farmers.
It is one of the few sciences where amateurs can still play an active role,
especially in the discovery and follow-up to phenomena such as light curves of
variable stars, the discovery of asteroids and comets, etc.
During the 20th century, the field of professional astronomy split into
observational and theoretical branches. Observational astronomy is focused on
acquiring data from observations of astronomical objects, which is then
analyzed using basic principles of physics. Theoretical astronomy is oriented
toward the development of computer or analytical models to describe
astronomical objects and phenomena. The two fields complement each other,
with theoretical astronomy seeking to explain the observational results and
observations being used to confirm theoretical results.

Changes in the world
For centuries, the geocentric worldview that the Sun and other planets revolved
around the Earth is not questioned. This vision was what our senses are noted.
In the Renaissance, Nicolaus Copernicus proposed a heliocentric model of the
Solar System. His work De Revolutionibus Orbium Coelestium was defended,
disclosed and corrected by Galileo
Galilei and Johannes Kepler, author
deHarmonices Mundi, which was
developed for the first time the third
law of planetary motion.
Galileo added the novelty of the use
of the telescope to improve their
observations. The availability of
accurate observational data led to
investigate theories to explain the
observed behavior (see his book
Sidereus Nuncius). At the
beginning only rules were obtained
ad-hoc, as the laws of planetary motion of Kepler, discovered in the early
seventeenth century. It was Isaac Newton who extended toward the celestial
bodies the theories of earth's gravity and shaping the Law of universal
gravitation, inventing and celestial mechanics, which explained the motion of
the planets and achieving join the gap between the laws of Kepler and the
dynamics of Galileo. This also marked the first unification of astronomy and
physics.

Astronomy in the century XlX
At the end of the 19th century it was discovered that multitude of lines of
spectrum (regions where there was little or no light) could be observed to
decompose the light of the Sun. Experiments with hot gases showed that the
same lines could be observed in the spectrum of gases, specific lines
corresponding to different chemical elements. In this way showed that the
chemical elements in the Sun (mostly hydrogen) could be found equally in the
Earth. In fact, helium was
first discovered in the
spectrum of the Sun and only
later his name was found in
the land, hence.
It was discovered that stars
were distant objects and with
the spectroscope showed that
they were similar to the Sun,
but with a wide range of
temperatures, masses, and sizes. The existence of the milky way as a separate
Star Group was not demonstrated until the 20th century, along with the
existence of external galaxies and, shortly after, laexpansion of the universe,
observed in the effect of the shift to the red. Modern astronomy has also
discovered a variety of exotic objects
such as quasars, pulsars, radio, black
holes, neutron stars, and has used these
observations to develop physical theories
that describe these objects. Cosmology
made great advances during the 20th
century, with the model of the Big
Bangfuertemente supported by
the evidence provided by astronomy and
physics, such as the background radiation
of microwave, Hubble's law and
cosmological abundance of the chemical elements.

Telescope
It is called alinstrumento optical
telescope that allows you to view distant
objects with greater detail than with the
naked eye to capture electromagnetic
radiation, such as light. It is a
fundamental tool in astronomy, and each
development or improvement of this tool
has allowed progress in our
understanding of the Universe. Thanks to
the telescope -ever since Galileo Galilei
in 1610 used it to look at the Moon, the
planet Jupiter and the stars - the human
being could finally begin to know the true
nature of the celestial bodies which
surround us and our location in the
universe.
the first Telescope
In May of 1609, Galileo Paris receives a
letter from the French Jacques Badovere,
one of his former students, who confirms
a rumor insistent: the existence of a telescope that allows viewing of distant
objects. Made in Holland, this telescope would have allowed already seeing
stars invisible to the naked eye. With this single description, Galileo, which no
longer gives courses to Cosimo II de' Medici, he built his first telescope. On the
contrary that the Dutch telescope, this not deforms the objects and the increases
by 6 times, or twice that of the opponent. It is also the only of the time that you
successfully obtain a right image through the use of a diverging lens in the
eyepiece. This invention marked a turning point in the life of Galileo.The
advantages of a large refractor telescope in front of a large telescope reflection.
The refracting telescope is in what most people think of when you hear the word
"telescope". A large end optical lens is used to focus the light to a much smaller
extent at the other end, enlarging the image and making dark objects appear

ighter in the night sky. While refraction model has some inherent limitations
to the size scale of observation, a great refractor telescope has some advantages
over a large reflecting telescope.
Easeofuse
A refractor telescope is a very simple device, and use one to scan the night sky
is simple and intuitive. The objective lens, the big at the end of the telescope
lens, is fixed in place and does not require adjustments. Any approach occurs in
the eye, where the hand and the user's attention is fixed in any case. A reflecting
telescope optics, on the other hand, needs to be calibrated regularly to avoid a
serious degradation of the image.
Durability
Despite the fragile lenses involved, a refractor telescope is tough enough. A
large telescope objective lens is made of a glass is much more dense than the
thin material of a reflector telescope, so it is more likely that it will survive
intact to minor accidents. The sealed tube also protects the optics inside of that
dirty, while reflection telescopes often require a complex cleaning of indoor
optical mirrors. This can be especially difficult for large telescopes, lenses can
be extremely difficult to reach from outside.
Imagequality
On the scale of a large amateur telescope, the method of collection of light in a
refractive telescope has a couple of major advantages over a reflecting
telescope. The reflector telescope will suffer a certain loss of light due to the
diagonally tilted secondary mirror obstruction. This means that dark objects
tend to look brighter on a refractor telescope. The sealed tube also eliminates
some potential sources of distortion of the image, such as rebel air currents,
which the reflecting telescopes must fight.
DIYtelescopes
In general, a lens of soil is a more indulgent piece of a home mirror optics. Small
errors will be less visible in a lens as a mirror, where slight variations can result
in a great loss of image quality. Therefore, very useful for the large reflecting
telescopes lenses can grind glass porthole, making this design a popular choice
for fans who wish to build your own telescope at home.
Rayos X
In its more than eight years in orbit, the telescope space-based X-ray of the
European Space Agency (ESA), XMM-Newton, has changed our view of the
universe. XMM-Newton has revealed the importance of the black holes as
"engines" energy of the galaxies; has helped us to understand the stellar

On August 21,
scarcely finished
its second
telescope (eight
increases) ,
presents it to the
Senate of
Venice.
The
Demonstration
takes place in
the
top of the
Campanile of
the
square of San
corpses neutron stars, supernova remnants; has
observed galaxies in the early universe; has discovered
phenomena all new.
X-ray astronomy is the study of astronomical objects
at X-ray wavelengths. Typically, X-ray radiation is
Marco.
The
produced by synchrotron
emission (the result of
electrons orbiting magnetic
field lines), thermal
emission from thin gases
above 10 (10 million)
kelvins, and thermal
emission from thick gases
above 10 Kelvin. Since X-rays are absorbed by the
Earth's atmosphere, all X-ray observations must be
performed from high-altitude balloons, rockets, or
spacecraft. Notable X-ray
sources include X-ray binaries, pulsars, supernova
remnants, elliptical galaxies, clusters of galaxies, and
active galactic nuclei.
X-rays were first observed and documented in 1895 by
Wilhelm Conrad Röntgen, a German scientist who found them when
experimenting with vacuum tubes. Through a series of experiments, Röntgen
was able to discover the beginning elements of radiation. The "X", in fact, holds
its own significance, as it represents Röntgen's inability to identify exactly the
type of radiation.

Stellar astronomy
At a distance of about eight light-minutes, the most frequently studied star is the
Sun, a typical main-sequence dwarf star of stellar class G2 V, and about 4.6
billion years (Gyr) old. The Sun is not considered a variable star, but it does
undergo periodic changes in activity known as the sunspot cycle. This is an
11year fluctuation in sunspot numbers. Sunspots are regions of lower-thanaverage
temperatures that are associated with intense magnetic activity.

The Sun has steadily increased in luminosity over the course of its life,
increasing by 40% since it first became a main-sequence star. The Sun has also
undergone periodic changes in
luminosity that can have a
significant impact on the Earth.
The Maunder minimum,
for example, is believed to have
caused the Little Ice Age
phenomenon during the
Middle Ages.
The visible outer surface of the
Sun is called the photosphere.
Above this layer is a thin region
known as the chromosphere.
This is surrounded by a
transition region of rapidly increasing temperatures,
and finally by the super-heated corona.
At the center of the Sun is the core region, a volume of sufficient temperature
and pressure for nuclear fusion to occur. Above the core is theradiation zone,
where the plasma conveys the energy flux by means of radiation. Above that
are the outer layers that form a convection zonewhere the gas material transports
energy primarily through physical displacement of the gas. It is believed that
this convection zone creates the magnetic activity that generates sun spots. A
solar wind of plasma particles constantly streams outward from the Sun until,
at the outermost limit of the solar system, it reaches theheliopause. This solar
wind interacts with the magnetosphere of the Earth to create the Van Allen
radiation belts about the Earth, as well as the aurora where the lines of the
Earth's magnetic field descend into the atmosphere.
Radio astronomy
Radio astronomy studies
radiation with wavelengths
greater than approximately
one millimeter. Radio astronomy is
different from most other forms of
observational astronomy in that the
observed radio waves can be treated as
waves rather than as discrete photons.
Hence, it is relatively easier to measure

oth the amplitude and phase of radio waves, whereas this is not as easily
done at shorter wavelengths.
Although some radio waves are produced by astronomical objects in the form
of thermal emission, most of the radio emission that is observed from Earth is
the result of synchrotron radiation, which is produced
when electrons orbit magnetic fields. Additionally, a number of spectral lines
produced by
interstellar gas, notably
the hydrogen spectral line
at 21 cm, are observable
at radio wavelengths. A
wide variety of objects
are observable at radio
wavelengths,
including supernovae,
interstellar gas, pulsars,
and active galactic

Understanding our world: the importance of
astronomy today.
"They say that astronomy is the oldest science. There is no doubt that a look at
the majestic Milky spreading across the sky on a clear night, it must have
amazed people of all ages and cultures. Nowadays, astronomy stands out as one
of the most modern and dynamic, sciences that uses some of the most advanced
technologies and the most sophisticated techniques available to scientists. These
are exciting for astronomy times, because technology allows us to study objects
in the distant corners of the universe and detect evidence of planets around other
stars. "We can begin to answer a fundamental question that fascinates each one
of us: are we alone in the universe?"
These are the words of Tim de Zeeuw, Director General of the European
Southern Observatory ESO, in a magazine
titled "A universe of discovery", and posted
that on the occasion of its 50 years of
existence. This publication presents, in a 48-
page full-color, past and present
achievements as the future prospects of this
successful European international
organization, which manages a total of three
cutting-edge astronomical observatories in
Chile. In the following I would like to quote
some other paragraphs of the same
magazine, for its general
meaning: "Astronomers tackle
key issues that challenge our
minds and our imagination. How were the
planets formed? How did life on Earth
develop? Is life in the universe omnipresent? How are galaxies formed?
What is dark matter and dark energy?"
"Astronomy is a science modern and high technology that explores the space
that surrounds us and tries to explain the amazing processes that take place in
this huge volume. "Studying our beginning and tries to predict the future of our
Solar system, our Galaxy, the milky way, as well as the entire universe."
"Astronomy is a science of extreme conditions. Works with larger distances,
longer periods of time, more massive objects, higher temperatures, more intense
electric and magnetic fields, higher and lower densities and known extreme
energies."

"Astronomy is a physical science which is based on observations. With the
exception of some bodies of the Solar system, we can not touch objects that we
investigate. We interpret the phenomena observed through the application of
our knowledge of natural laws."
"To enable these
observations,
astronomy employs
some of the
instruments and more
sophisticated methods ever
designed by human beings.
High technology plays a
very important role in
astronomy." "Astronomy is
an integral part of our
culture and is a powerful
representation of
our inherent curiosity and desire to learn more about our environment. Now that
we have explored most of the Earth's surface, the astronomy is exploring the
vast Terra Incognita that surrounds us."
"It also contributes to better understanding our fragile environment and the
extraordinary fact of life possible on Earth. Through astronomy we have been
able to truly appreciate how precarious is our position in the universe." "It
provides also the necessary framework for future expeditions and the possible
expansion of the human species through space. Investigating the conditions
prevailing there outside, we prepare the tasks of the next generations."
"Observe distant galaxies means looking back in time, sometimes almost to the
beginning of the universe itself, when time began." It means studying the
universe, how they formed the stars and the planets, including the Earth has
evolved. Astronomy is the study of the origins. It is also the study of apocalyptic
events. And great mysteries. However and above all, is the boldest attempt of
mankind to understand the world in which we live."
The future of astronomy
Understanding our world: the importance of the is dangerous speculation about
what will happen. I told the Danish physicist Niels Bohr: "prediction is very
difficult, especially if it comes to the future". But on the other hand, it is true

that we all have in mind some schema, a point of view of how it will be the
future of our profession.
The astronomers saw, during the twentieth century, radical changes in the way
of doing astronomy. The most important change had to do with the opening of
the windows "invisible" of the electromagnetic spectrum. Let me explain this.
Through the centuries, the astronomical observations were made with the first
eye (for example, in the ancient Mesoamerican civilizations) and then using
telescopes. In 1609 Galileo knew the invention of the telescope and was built
one, starting to be observed in the heavens. He soon discovered many things.
The Moon was not the perfect sphere that until then it was believed, but that
was full of craters. Galileo discovered many things, including that to Jupiter,
and was accompanied by several satellites.
Since Galileo, until the early 1930s, the whole astronomy was made by
observing the light that reaches us from the stars. What is light? The light is a
form of energy that travels through space at great speed; its speed is
approximately 300,000 kilometers per second. If a cosmic body emits light
(for example, a star) we can, based on the discovery of such light, not only
know the form of the body, but also to determine many things, such as its
temperature, its
chemical
composition, and so
on. Our eye is sensitive
to light and for a
long time human
beings believed
that light was the
only form of energy
with these
characteristics. But the
studies of the Scottish
physicist James Clerk
Maxwell was clear, in the nineteenth century,
that the light was part of a general phenomenon, only one of the many waves
emitted by celestial bodies.