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ASTR 1102-002 2008 Fall Semester. Joel E. Tohline, Alumni Professor Office: 247 Nicholson Hall [Slides from Lecture20]. Chapter 23 : Our Galaxy and Chapter 24: Galaxies. Schematic Illustration of Our (Milky Way) Galaxy. Stellar Populations. Stellar Populations. Stellar Populations.
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ASTR 1102-0022008 Fall Semester Joel E. Tohline, Alumni Professor Office: 247 Nicholson Hall [Slides from Lecture20]
Schematic Illustration of Our (Milky Way) Galaxy
Stellar Populations • What about “Pop III” ?
Stellar Populations • We are only able to study and delineate well these different stellar populations in our own MW Galaxy • The presumption is that all other galaxies contain these same populations of stars, although the fraction of stars belonging to Pop I vs. Pop II varies from galaxy to galaxy.
Center of Our Milky Way Galaxy Evidence for a Massive Black Hole at the
Individual Stars…(early in the semester) • Location in Space • Coordinate (angular) position on the sky • Distance from Earth • Motion through Space • Motion across the sky (“proper” motion) • Motion toward/away from us (radial velocity) • Intrinsic properties • Brightness (luminosity/magnitude) • Color (surface temperature) • Mass • Age
(now let’s discuss)…Individual Galaxies • Location in Space • Coordinate (angular) position on the sky • Distance from Earth • Motion through Space • Motion across the sky (“proper” motion) • Motion toward/away from us (radial velocity) • Intrinsic properties • Brightness (luminosity/magnitude) • Color (surface temperature) • Mass • Age
Individual Galaxies • Location in Space • Coordinate (angular) position on the sky
Individual Galaxies • Location in Space • Coordinate (angular) position on the sky • Distance from Earth
Individual Galaxies • Location in Space • Coordinate (angular) position on the sky • Distance from Earth • Motion through Space • Motion across the sky (“proper” motion) – None observable! • Motion toward/away from us (radial velocity) – Extremely revealing discovery made by Slipher, Hubble, Humason
Individual Galaxies • Location in Space • Coordinate (angular) position on the sky • Distance from Earth • Motion through Space • Motion across the sky (“proper” motion) – None observable! • Motion toward/away from us (radial velocity) – Extremely revealing discovery made by Slipher, Hubble, Humason
Individual Galaxies • Location in Space • Coordinate (angular) position on the sky • Distance from Earth • Motion through Space • Motion across the sky (“proper” motion) – None observable! • Motion toward/away from us (radial velocity) – Extremely revealing discovery made by Slipher, Hubble, Humason
Individual Galaxies • Location in Space • Coordinate (angular) position on the sky • Distance from Earth • Motion through Space • Motion across the sky (“proper” motion) – None observable! • Motion toward/away from us (radial velocity) – Extremely revealing discovery made by Slipher, Hubble, Humason
Individual Galaxies • Location in Space • Coordinate (angular) position on the sky • Distance from Earth • Motion through Space • Motion across the sky (“proper” motion) – None observable! • Motion toward/away from us (radial velocity) – Extremely revealing discovery made by Slipher, Hubble, Humason