Astr 205 - Study guides, Class notes & Summaries

Newton concluded that some force had to act on the moon because - a force is needed to pull the moon away from straight-line motion. When we say that gravitation is universal we mean that - it is a property of all matter. Which of the following people did not accept a heliocentric model for the universe? - Tycho A(n) __________ is a circle whose center is located on the circumference of another circle. - deferent Galileo's telescopic discoveries of mountains on the moon and spots on th...

The disk of the galaxy is older than the halo. - F The density wave theory explains spurs and branches along the spiral arms. - F Giant molecular cloud complexes are located in spiral arms. - T Shapley found the distance to the center of the galaxy by studying the distance to open clusters - F The center of our galaxy is located in the direction of the constellation of Orion - F The rapid rotation in the outer disk suggests that our galaxy is more massive than previously thought. - T S...

The radio lobes that flank some radio galaxies produce mainly - synchrotron radiation. The fact that many radio lobes emit more intensely from the side away from the galaxy suggests that - they are created by jets from the galaxy. The central galaxy in a double-lobed radio source is usually - a giant elliptical galaxy. The hot gas of a radio lobe could be held together by - collision with the intergalactic medium. Head-tail galaxies are - a, b and c. If the red shifts of quasars arise f...

Synchrotron radiation is produced by - high-velocity electrons moving through a magnetic field A Type la supernova is believed to occur - when a white dwarf exceeds the Chandrasekhar limit The material that accretes onto a neutron star or black hole is expected to emit x-rays because - the material will become hot enough that it will radiate most strongly at x-ray wavelengths. A planetary nebula - produces an emission spectrum. The main sequence has a lower limit because - there is a...

The first stars to form in our galaxy - had highly elliptical orbits The most likely theories to explain the spiral structure of spiral galaxies are - selfsustaining star formation and the density wave theory. A Type II Cepheid has been located in a distant globular cluster with a period of 10 days. What is the star's absolute magnitude? - −1 Besides the obvious difference in shape, elliptical galaxies differ from spirals by - containing little gas and dust, and few, if any, newly form...

ASTR 205 or Astronomy 205 Assignment 1- Observational Study Athabasca University 2024

Athabasca University ASTR 205 PRACTICE QUESTIONS and Answers

ASTR 205 (Astronomy 205) Short-answer Quiz 4 Athabasca University 2024.

Athabasca University ASTR 205 PRACTICE QUESTIONS and Answers

ASTR205 All Chapters – Complete Study Guide – Qs & As