Big Bang vs. Steady State
BBC website with video clips discussing the evidence for the two theories
An artists impression of a black hole, an area in space so massive, with gravity so extreme, that nothing can escape (not even light), swallowing a nearby star. Said to have been detected by Nasa's Chandra Observatory and the Hubble telescope
Cosmic Microwave Background image from the COBE satellite. CMB is thought to originate from photons of light created just after the Big Bang and released as the Universe cooled. The wavelengths have been stretched and now shows up everywhere in the Universe a microwave radiation. Colour variations represent very small changes in temperature.
More detailed CMB image with the signal from our Galaxy removed showing temperature fluctuations of +-200 microKelvin
A supernova remnant some 6,500 light years from Earth. Probably exploding in 1054 AD
A region of current star formation, subject of the famous 'Pillars of Creation' photograph, some 6,500 light years away.
History of the Universe - Part 1
A nice romp through the history of the Universe
History of the Universe - Part 2
Second part including the life cycle of the sun
Image from the Canada-France-Hawaii telescope in Hawaii. The horsehead is just a portion of the dustcloud.
How the Sun will die
Short film showing what will happen to the Earth and the impact of a red giant on the inner planets
Large Sun (Star)
Stars with more than 5 times the mass of our Sun run out of fuel and form red supergiants with very hot cores, hot enough to produce Fe and Ni. Further layer will produce Si, S then O, Ne, Mg and finally Ne and He.
Life and death of a star
Great visual but really needs a voiceover
Life cycle of a star
High school project. Well explained
Life cycle of stars
Image showing the life cycle of our Sun and more massive stars.
Resulting from the death of massive stars 4 to 8 times the size of our Sun. A neutron star is so dense that on Earth one teaspoon would have a mass of a billion tons. Usually about 20km in diameter with a mass 1.4 times that of Earth.
Observing the Universe - IR
Brief video explaining how the Herschel space telescope is using infrared radiation to look out into space. IR doesn't pass through the Earth's atmosphere so the telescope has to be outside of the atmosphere
Visible to the naked eye, just south of Orion's belt. 24 light years across and 1,500 light years away, it is the nearest stellar nursery to Earth with around 700 stars in all stages of formation.
At the death of a star of similar size to our Sun, the hydrogen runs out and the star starts to collapse. The core temperature rises as helium fuses to form Carbon, Nitrogen and Oxygen and the star swells.
Red Supergiant c.f. our Sun
Nasa images compiled to give an indication of the relative sizes of our planets, Sun and other bodies such as Red Giants and a Red Supergiant (Betelguese)
Red Supergiant c.f. our Sun 2
Indication of size:
Sirius is the brightest star in the sky
Pollux, about 34 light years away was the first star to be confirmed with an extrasolar planet.
Aldebaran is a red giant about 65 light years away.
Betelgeuse is a red supergiant, as is Antares
SETI - Search for Extra Terrestrial Intelligence
An exploding star will supernova and this can last weeks or months. The resulting explosion can trigger new star formation.The last supernova to be seen in the Milky Way was in 1604.
The death of stars and black holes
ASTR 100 Honours project from the research school of astronomy and astrophysics from the Australian National University.
A dying star, no longer undergoing fusion, with a mass similar to our Sun and a size similar to Earth. A White Dwarf will cool to a Black Dwarf.
Why telescopes in space ?
Water vapour in the atmosphere absorbs infra red.
Visible light makes it through the atmosphere but images are blurred
The Earth's atmosphere blocks X-rays and gamma rays..