Astronomy: Stars & Light

Astronomy: Stars & Light SPACE is a very large area and for scientists to accurately and efficiently observe/study natural phenomena, different units of measurement are used. AU = astronomical unit . A unit of distance equal to 93 million miles (distance from our Sun to Earth) Parsec = measurement between two celestial objects Light – year = The distance light travels in 1 yr (9.5 trillion kilometers)

Astronomy: Electromagnetic Spectrum The electromagnetic spectrum consists of all radiation and energy which derives from our Sun and spreads out as it travels. All ‘EM’ radiation travels at 186,000 miles per second (speed of light) Each type of radiation has a different wavelength, which can increase or decrease the amount of energy. The shorter the wavelength = more dangerous/harmful radiation Visible light (white) is a mixture of different wavelength which control the color (interpreted by our eyes and brain) 400nm – 700nm

Astronomy: Doppler Effect The Doppler effect is the changes to wavelengths as light or sound travels through space or air The change of wavelength can affect the perceived color by an observer. In astronomy – blue shift (compressed – towards), red shift is (stretched – going away)

Astronomy: You’re a Shinning Star Our Sun: Facts: Contains 99.9% of all energy in our Solar System Every second matter is turned into ENERGY – 4 million tons Earth fits into ‘empty Sun’ 1 MILLION times Takes hydrogen and produces other elements for the solar system to use Axis rotation every 27 days 109 times larger radius than Earth Light is produced by energy in the Sun, but takes 200,000 years to reach and escape the Sun’s surface. Iron in a humans bloodstream was originally made in the core of exploded stars (planetary nebula) Solar flares can reach 80 million degree Celsius

What’s in a Shinning Star: Our Sun’s Anatomy: Inner Core = main engine and heat production – 15 million C, hydrogen into helium Radiative Zone = photon (beams of energy/radiation) moves through this zone Convective Zone = convection currents transport heat through this layer (not hot enough to radiate) SURFACE & ATMOSPHERE: Photosphere = Light from the Sun is emitted Chromosphere = Color sphere of the Sun’s atmosphere. Sits above the photosphere Corona = ‘crown’ surrounds the Sun. High Temp Prominence = hot charged plasma following magnetic fields that are not released Solar Flare = the release of prominences into space Sun Spots = cooler spots on the Sun’s surface

Astronomy: You’re a Shinning Star Our Sun: Energy to fuel a solar system Nuclear fusion = combination of elements under heat and pressure Occurs inside the Sun’s core 15 million degrees Celsius Hydrogen atoms are converted into helium and combine to create a molecule. Hydrogen is then released in this process.. Large volumes of ENERGY is produced from matter turns to energy and release of hydrogen Proposed 5.5 billion years left of available hydrogen and helium ‘FUEL’ is left

A classification of STARS: The life expectancy of a star is based upon its MASS (larger = shorter life, smaller = longer life) Nebula = cloud of dust and material Stellar nebula are the building blocks of newly born stars whereby gravity and attraction work to form the early stages of a star’s life. A star is born - depending on the mass it can be part of the ‘main sequence stars’ as either small/medium or large star. Once the hydrogen has been converted into helium, the star will begin to ‘die’ and expand into either a red supergiant or red giant (depending on the mass) The thermal expansion out weighs the gravitational attraction towards the star’s core Carbon atoms are created in the core as the star dies, other elements like iron are replaced in the core and create a repulsion shock wave which overpowers the force of gravity. Thus, creating a SUPERNOVA explosion. Depending on the mass – black hole or neutron star; white/black dwarf are created (no fusion or energy released)

It all began with a big bang! 13.6 billion years old Expanding universe theory from a central point and time It all began with a big bang!