Deep Space Objects

Variable stars Caused by pulsations in the stars – expansions make them cooler and dimmer – Contractions make them hotter and brighter Cepheid variables- – Absolute magnitude is based on the length of the bright/ dim period. – The longer the bright/dim cycle the higher the absolute magnitude. By comparing the cepheid’s apparent and absolute magnitude the distance to Earth can be determined

Neutron Stars ~100 million in our galaxy alone 1-2 solar masses, 10 km diameter Emit high energy: X-rays and Gamma-rays

Pulsars Rapidly spinning neutron stars – emit large amounts of radio waves along with light waves Pulses light due to enormous magnetic field – As the star rotates the beam of radiation is emitted along the magnetic axis much like a searchlight Magnetars are super magnetized spinning neutron stars

THE LIGHT HOUSE MODEL A rotating magnetic field explains the pulses from a neutron star

Eclipsing binary stars 2 stars that revolve around each other- involves a dim star and a bright star Super Novas Very massive red giants explode and the remaining mass condenses into a neutron star Can be more than a billion times more luminous than the sun

Galaxies Star systems that contain billions of stars Telescopes show us there are billions of galaxies in space Our galaxy is the Milky Way – contains 100 billion stars including our sun – Our solar system is a small part of a larger galaxy made up of billions of stars- like our sun

Galaxies occur in groups (local group) called clusters – many clusters form a super cluster The Milky Way is a part of a cluster of galaxies called a local group. There are 35 galaxies in our group.

Milky Way Galaxy side view of the Milky Way’s center. Made up of: globular clusters galactic nucleus nuclear bulge spiral arms disk note position of the Sun, just over half way out.

Types of Galaxies Spiral galaxies

Types of Galaxies Elliptical galaxies-

Types of Galaxies Irregular galaxies

Quasars discovered 1961 looked like stars that emit radio waves quasars is short for quasi-stellar radio sources appear faint but shown to be the most luminous objects in the space Quasar PK appears to be a faint star. The red shift shows it to be 12 billion light years away No known star can be seen at that distance so the quasar has to be about the same brightness as 10 trillion suns and a billion times more massive

Earth Region of Normal Galaxies Region of Active Galaxies Region of Quasars to 10 Mcyto 1 Bcy