Andromeda Galaxy: Location on Sky, Some Facts, Images || (11 minutes) This video describes the location of the Andromeda galaxy on the sky, gives a few facts about the galaxy, and shows images of the galaxy in visible, ultraviolet, and infrared light.
Doppler shift evidence for the supermassive black hole at the center of the galaxy is briefly discussed. |
Local Group of Galaxies, A Quick Tour || (20 minutes) This video shows sketches, maps, and photos of the Local Group of Galaxies. The Andromeda, Milky Way, and Triangulum galaxies are highlighted.
The companion galaxies for Andromeda are discussed. The companion galaxies of the Milky Way, the Large Magellanic and Small Magellanic Clouds, are discussed.
Approximate masses (from Google searches) are given. A few details of the Milky Way and Andromeda galaxies are discussed. |
Island Universe Debate, Cepheid Variable Stars
(15 minutes) This video discusses the debate in the early 1900s as to the location of some nebulae in relation to the Milky Way Galaxy. Shapley and Curtis debated the size of the universe and nature of the
nebulae in 1920. In the 1700s Kant used the term "Island Universe" to describe some of the nebulae as he believed they were there own large collection of stars, what we now call galaxies.
The video summarizes some of the reasoning for both sides of the debate. The video describes the light variability of Cepheid stars and the period luminosity relationship.
The video also has a sequence of sketches and photographs of the Whirlpool Galaxy as astronomy technology improved from 1845 to 2005.
Zone of Avoidance, Distribution of Galaxies || (10 minutes) This video gives a brief description, history, and explanation for the "Zone of Avoidance." The distribution of galaxies over the sky is shown for visible and infrared wavelengths. |
Types of Galaxies: Spiral, Elliptical, Irregular Hubble Images || ( 15 minutes) This video uses graphics and Hubble images to describe spiral, barred spiral, elliptical, and irregular galaxies. There is brief discussion on how spiral and elliptical galaxies form. The characteristics of spiral, elliptical, and irregular galaxies are listed. |
Large Elliptical Galaxies, Hubble Photos, Characteristics, Formation Theories ||(11 minutes) This video gives a brief overview of Elliptical Galaxies. Hubble photos of elliptical galaxies are presented. Their main features are noted and a general description is given on how they might have formed.|
Supermassive Black Holes in Galaxies, Detection, Correlation to Galaxy Mass || (12 minutes)
This video describes how it was determined that a supermassive black hole exists at the center of the Milky Way Galaxy. The video also describes how supermassive black holes are detected in more distant galaxies,. A brief explanation is given on the connection between the mass of the supermassive black hole and the mass of the host elliptical galaxy or the mass of the bulge of the host spiral galaxy. URLs are given for further reading and viewing of videos. |
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