Observing the Universe Stars & Galaxies Telescopes
Any questions for next Monday?
Light
Doppler effect
Doppler shift
Doppler shift
Spectra Doppler effect
Spectra
Stars
Star and planet formation Sun Low-mass star Brown Dwarf Earth Gravitational collapse of interstellar clouds Diversity of planets (mass, distance to central star, excentricity, chem. comp. etc.): interaction of many processes
Stellar evolution Planet evolution linked to stellar evolution Stars evolve through thermonuclear burning Change of chemical composition Typical evolution times: billions of years Solar-like stars (~ 1M ) become Red Giants
Stars
Hertzsprung-Russell diagram
Stars Ages: between 1 million and 10 (to 100) billions of years Chemical composition: 70% H, 28% He, rest heavy elements (and small variations) Diameter: 20 km (neutron star) to 900000000 km (e.g., Betelgeuze,650 solar radii) Kinematics: parallax and proper motion, Doppler shift and radial velocity Mass: 0,083-150 solar masses Temperature (surface): ~3000 up to 50000 K Brightness: 0,00001-100000 x Sun s brightness
Eta Carinae
Hertzsprung-Russell diagram
Spectral Class Prism Lines in stellar spectra Chemical elements Absorption Spectrum Which lines are visible depends on the star s temperature
Spectral Type Class Temperature Sample star O 33,000 K or more Zeta Ophiuchi B 10,500 30,000 K Rigel A 7,500 10,000 K Altair F 6,000 7,200 K Procyon A G 5,500 6,000 K Sun K 4,000 5,250 K Epsilon Indi M 2,600 3,850 K Proxima Centauri Oh Be A Fine Girl/Guy, Kiss Me!
The nearest star
InterStellar Medium (ISM) Components: stars, planets, gas, dust, radiation fields, magnetic fields, high-energy particles Chemical evolution of a galaxy through enrichment with heavy elements from the final stages of stellar evolution (SN)
Stars & Galaxies Stars group together to form galaxies, and they dominate the visible universe
The Milky Way
The Milky Way 360-degree photographic panorama of the entire galaxy, from the viewpoint of the solar system
NGC 7331 is often referred to as "the Milky Way's twin.
Galaxies Gravitationally bound system: 10 000 000 to 1 000 000 000 000 stars, interstellar medium of gas and dust, dark matter
Galaxies Whirlpool Galaxy
Galaxies Sketch of the Whirlpool Galaxy by Lord Rosse in 1845
Galaxies 1920s: Edwin Hubble - Cepheid variables in distant spiral nebulae These objects are far too distant to be part of the Milky Way.
Galaxies
Galaxies
Galaxy Morphology E: Elliptical S: Spiral SB: Barred Spiral Hubble classification scheme
Galaxy Morphology Halo of dark matter Dust Bulge Core Spiral arms Envelope M87, E1, Virgo cluster Ulaanbaatar, May 2007, M83, SAB(s)c Astronomy Lecture Series at the National University of Mongolia, Katrien Kolenberg
Andromeda: M 31= NGC 224 Spiral galaxy vom Typ Sb Distance: d = 670 kpc Moving towards us! Merging with the Milky Way in about 5 10 9 years This may build an elliptical galaxy Radius: 24 kpc Lots of small dwarf galaxies accompanying it, M32 = NGC221 und NGC205
Galaxy Groups and Clusters Seyfert's Sextet: a compact galaxy group
The Local Universe Virgo Supercluster
Observing Tools: Telescopes
Optical Telescopes * The refracting telescope: lenses * The reflecting telescope: mirrors * The catadioptric telescope: combination of mirrors and lenses
Refractor
Reflector Secondary mirror Primary mirror Newton Primär Cassegrain Coudé Focus Focus Focus Focus
The biggest reflecting telescopes on Earth ESO VLT 4 x 8,2m 2000+ Chile LBT 2 x 8,4m 2004 Arizona Keck 9,8m 1991 Hawaii SALT 11m 2005 South Africa Hobby-Eberle 9,2m 2000 Texas MMT 6,5m 2000 Arizona Selentschukskaja 6,1m 1975 Caucasus Palomar (Hale) 5,1m (200 Zoll) 1948 California Herschel 4,2m 1987 La Palma
Kitt Peak Observatory
Kitt Peak Observatory
Kitt Peak Observatory
Kitt Peak Observatory
Kitt Peak Observatory
Hubble Space Telescope
The biggest telescope in space: Hubble Space Telescope 2,4m (HST)
Hubble Space Telescope Lyman Spitzer
Hubble Space Telescope Polishing of Hubble's primary mirror
Hubble Space Telescope Early stages of Hubble's construction, 1980
Hubble Space Telescope Shuttle mission STS-31 lifts off, carrying Hubble into orbit.
Hubble Space Telescope The light from a star spread over a wide area instead of being concentrated on a few pixels
Hubble Space Telescope Astronauts work on Hubble during the first servicing mission
Hubble Space Telescope Improvement in Hubble images after the first service mission
Hubble Space Telescope One of Hubble's most famous images: pillars of creation where stars are forming in the Eagle Nebula.
Hubble Space Telescope Distant galaxies in deep space in a Hubble Ultra Deep Field photograph
Hubble Space Telescope Horsehead Nebula
See you next Monday!