Download Telescópios

Telescópios
Os telescópios trabalham com a refração e a reflexão de Luz.
Quais as propriedades da luz que devemos conhecer para entender o
funcionamento de um telescópio?
Difração
Reflexão e Refração
Imagens: resolução e sensibilidade
Difração da Luz
Difração
Difração
O
Interferência construtiva e destrutiva de ondas:
Difração
Difração
O
O Diâmetro do espelho ou lente
Influencia na resolução do
telescópio!!
Azul
1 rad = 360*60*60/2Pi segundos de arco
1 - Calcule a resolução angular dos telescópios abaixo, para o comprimento de onda de
400nm (luz visível):
a)
Telescópio de PVC, D = 3,6cm;
b)
Telescópio pequeno do laboratório, D = 10cm;
c)
Telescópio reflector do laboratório (Keck, Hubble, Magalhães e Soar), 15cm;
d)
Telescópio Celeston, D = 10”;
e)
Soar, D = 4m;
2 - Caso estes telescópios tenham a mesma magnificação (aumento), qual deverá ser a
diferença entre as imagens deles?
Difração
Difração
Com os nossos telescópios conseguimos ver a Andrômeda com esta resolução? NÃO!!!
Tempo de exposição, seeing, ...
Andes Chilenos: ESO, CTIO, SOAR
Compensar o Seeing Ruim (1993):
As lentes decompõe
a luz como um
prisma.
Aberração Cromática
Maior Telescópio refletor – 10m - Havai
Maior Telescópio refrator – 1m – Yerkes
Foco Newtoniano
Foco Cassegrain
Foco Coudé
The Very Large Telescope array (VLT) is the flagship facility for European ground-based
astronomy at the beginning of the third Millennium. It is the world's most advanced optical
instrument, consisting of four Unit Telescopes with main mirrors of 8.2m diameter and four
movable 1.8m diameter Auxiliary Telescopes. The telescopes can work together, to form a giant
‘interferometer’, the ESO Very Large Telescope Interferometer, allowing astronomers to see
details up to 25 times finer than with the individual telescopes. The light beams are combined in
the VLTI using a complex system of mirrors in underground tunnels where the light paths must
be kept equal to distances less than 1/1000 mm over a hundred metres. With this kind of
precision the VLTI can reconstruct images with an angular resolution of milliarcseconds,
equivalent to distinguishing the two headlights of a car at the distance of the Moon.
http://www.eso.org/public/teles-instr/vlt/
http://www.mmto.org/
The huge "dish" is 305 m (1000 feet) in diameter, 167 feet deep, and covers an area
of about twenty acres. The surface is made of almost 40,000 perforated aluminum
panels, each measuring about 3 feet by 6 feet, supported by a network of steel cables
strung across the underlying karst sinkhole. It is a spherical (not parabolic) reflector .
http://www.naic.edu/
Suspended 450 feet above the reflector is the 900 ton platform. Similar in design to a
bridge, it hangs in midair on eighteen cables, which are strung from three reinforced
concrete towers. One is 365 feet high, and the other two are 265 feet high. Uma forma de melhorar a baixa resolução que se tem em ondas de rádio
http://www.vla.nrao.edu/
Gaia
ESA - Europian Space Agency
Lançado em 2013 pelo foguete russo Soyo (Guiana Francesa)
Objetivo de fazer um mapa tridimensional do universo
Medir com precisão distâncias, composições, movimento, T, etc de estrelas e galáxias
Um substituto do Hubble
http://sci.esa.int/gaia/
Gaia is an ambitious mission to chart a three-dimensional map of our
Galaxy, the Milky Way, in the process revealing the composition,
formation and evolution of the Galaxy. Gaia will provide unprecedented
positional and radial velocity measurements with the accuracies
needed to produce a stereoscopic and kinematic census of about one
billion stars in our Galaxy and throughout the Local Group. This
amounts to about 1 per cent of the Galactic stellar population
http://irsa.ipac.caltech.edu/Missions/iras.html
http://irsa.ipac.caltech.edu/Missions/msx.html
The purpose of the Cosmic Background Explorer (COBE) mission was to take precise
measurements of the diffuse radiation between 1 micrometer and 1 cm over the whole
celestial sphere. The following quantities were measured: (1) the spectrum of the 3 K
radiation over the range 100 micrometers to 1 cm; (2) the anisotropy of this radiation
from 3 to 10 mm; and, (3) the spectrum and angular distribution of diffuse infrared
background radiation at wavelengths from 1 to 300 micrometers.
http://science.nasa.gov/missions/cobe/