Unit 3 Part 1 Notes - Universe & Big Bang, Galaxies & Stars PDF

Unit 3 Part 1 Notes The Universe & Big Bang, Galaxies & Stars Great Neck South Middle School  Origins of the Universe Universe: All space, matter, and energy - the Universe is vast, and is about 13.7 billion years old. Big Bang Theory: All matter and energy in the Universe starte...

Unit 3 Part 1 Notes The Universe & Big Bang, Galaxies & Stars Great Neck South Middle School  Origins of the Universe Universe: All space, matter, and energy - the Universe is vast, and is about 13.7 billion years old. Big Bang Theory: All matter and energy in the Universe started out concentrated in a small area and, after an explosion, matter began to organize itself into subatomic particles and atoms (mostly hydrogen and helium) Our Universe is Expanding The Universe has continued to expand and is expanding today. EVIDENCE: Red-shift 1.) ________________ in spectra of galaxies Cosmic Background Radiation 2.) _____________________________ coming from all directions in the Universe. (leftover from explosion)  _________________ Electromagnetic Energy - various types of waves that transmit energy through space Speed of light All types travel through space at 3.0 x 108 m/s (___________________) ESRT Pg. 14 ____________________ Wavelength - the distance between two successive crests or troughs ____________________ Frequency - the number of waves that pass a certain point in a given period of time Frequency depends on wavelength - the longer the wavelength, the lower the frequency  ESRT Pg. 14 Electromagnetic Spectrum Chart Practice 1. 3. 2. 4.  ESRT Pg. 14 Electromagnetic Spectrum Chart Practice 5. 6. The ________________________ Doppler Effect is apparent shift in wavelengths of an electromagnetic wave. When a light source is moving ____________ towards an observer, the shorter wavelengths of light appear ____________. – The spectrum shifts towards the shorter wavelengths (________________). blue-shift  When a light source is moving ____________ away an observer, the longer wavelengths of light appear ____________. – The spectrum shifts towards the longer wavelengths (________________). red-shift Big Bang Evidence: Red-shift blue red Moving away from us Moving toward us  Galaxy ________________ - a collection of billions of stars and various amounts of gas and dust held together by gravity. shape *They are categorized by ____________  Our Milky Way Galaxy spiral Our own galaxy is ______________ shaped, and contains over 200 billion stars!  Formation & Evolution of Stars Stars originate from clouds of gas and dust that swirl, condense and form balls of gases held together by gravity __________ Stars are formed in huge celestial structures nebula called ___________.  Formation & Evolution of Stars protostar From a nebula comes a ______________ (early star) – Nebula is now spherical – Mass, gravity and temperature increases  Formation & Evolution of Stars When the mass, temperature and pressure get high enough, ______________ nuclear fusion begins - A STAR IS BORN! – TONS OF ENERGY! Radiates out and travels through space as electromagnetic energy.  Low & Medium Mass Stars Spend most of their lives as main sequence stars, mass further evolution depends on the star's ________. Expand to red giant Burn all fuel, blow up, remaining core = white dwarf Example: our Sun  High Mass Stars Star remnants that are over 1.5 times the mass of our shorter Sun exist for a ______________ time (100,000,000 years) as MAIN SEQUENCE stars Expand to red supergiant Explode as supernova _______________ High mass = neutron stars ____________ Very high mass star Black holes = _______________  Classification of Stars Stars are classified by their 1. ___________ Luminosity (brightness), and 2. Temperature ___________ As temperature increases, star color changes from red (cooler) to blue (hotter). See H-R star chart in ESRT pg. 15. 90% of all stars are categorized as main sequence stars. Stars spend most of their “life” as main sequence stars. PAGE 15 ESRT  Review 1. When nuclear fusion begins in the core of a star, A.lighter elements (H) combine to form heavier elements (He) B.heavier elements (He) combine to form lighter elements (H) 2. What is the main property that determines which 3. Another term for the brightness of a star is path a stellar nebula takes in its life cycle? A.Temperature A.Temperature B.Luminosity B.Color C.Color C.Brightness D.Shine D.Mass 4. The “fuel” of the Sun is A.Helium B.Oxygen C.Oil and various hydrocarbons D.Hydrogen