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UNIT 7.5
STARS,
CONSTELLATIONS
AND GALAXIES
Stars
• Spherical body.
• Generates light and heat through nuclear
reactions.
• Most of them consist of gases, hydrogen
and helium.
Stars
Characteristics:
•Colour: depending on the temperature
they can be red, yellow, orange, white or
blue.
•Size: all stars are enormous, but some are
bigger than others.
•Luminosity: depends on the amount of
light from the star that reaches the Earth.
Obviously it also depends on how far it is
from us and how big it is.
Constellations
•Stars are divided into eighty-eight groups.
•Their names come from classical mythology,
animals and objects because of the shapes
they form in a bi-dimensional point of view.
•Ursa Major: a constellation that can be seen
all year round.
•Orion. Can only be seen in winter.
•Hercules can only be seen in summer.
Nebulae
Clouds of dust and gas
Some are illuminated by stars. That’s why
we can see them.
This gas and dust can join and form a new
star.
Nebulae: la tarántula
Nebulae: la gaviota
.
Nebulae: la hélice
La Nebulosa de la Hélice es uno de los
ejemplos más brillantes y próximos de
nebulosa planetaria, una nube de gas creada
al final de la vida de una estrella similar al
Sol.
Los gases más externos de la estrella
expulsados al espacio asemejan, desde
nuestro privilegiado punto de vista, como si
estuviésemos mirando a través de una hélice
.
El núcleo estelar resultante, destinado a
convertirse en una estrella enana blanca
Galaxies
•Enormous groups of rotating stars, gases
and dust.
•There are three types according to their
shape. Elliptical, spiral and irregular.
•Milky way, our galaxy. We are placed on the
edge of one of its arms