DSST Astronomy notes 1

Neutron star what is left after the explosion of a

Info icon This preview shows pages 11–13. Sign up to view the full content.

Neutron Star – what is left after the explosion of a Supernova (less than 3 solar masses) (e.v.4.a) The densest form of matter to exist (e.v.5) Pulsar – a neutron star that is rapidly spinning (e.v.5.a) Releasing pluses of radiation in the form of radio waves, or x-ray, or gamma ray pulses (e.v.5.b) emit more radiation in the radio wavelength than the visible light wavelengths (e.v.5.b.i) they are not detected by their light but rather their radio emissions
Image of page 11

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

(e.v.6) Black Hole – what is left after the explosion of a supernova (more than 3 solar masses) (e.v.6.a) So compact and such gravitational force nothing can escape from it (e.v.6.b) Consists of two parts (e.v.6.b.i) Singularity – center of black hole (e.v.6.b.ii) Event Horizon - Surface of the black hole 117) Metals – all elements heavier than hydrogen and helium a) Metallicity of an object is the percentage of its composed heavier elements (other than Hydrogen and Helium) a.i) Also may correlate to its age 118) Classifying Stars – Population category only relates to its age and metallicity a) Population I – youngest stars a.i) Tend to be found in open clusters a.ii) Highest metallic content a.iii) Sun is Population I star b) Population II – oldest stars found in the universe b.i)Have very low metal content, around .1% b.ii) Tend to be found in globular clusters and in halos of galaxies b.iii) Less luminous and cooler c) Population III – are stars with the lowest metallicity (no metallicity) c.i) One composed entirely of Hydrogen and Helium c.ii) none have been observed 119) Hydrogen and Helium the most abundant elements in stars in the solar system 120) Vast majority of stars and the sun are in a steady state, neither expanding or contracting 121) Hydrostatic Equilibrium – balance between the weights of various layers and the pressures that support them a) Surface and internal temperatures of stable stars is balanced 122) The Perfect Gas Law – states that the pressure is proportional to the density and temperature of the gas 123) Stellar thermal Energy – energy associated with the motions of the molecules in a star a) Internal heat, stored in a gas is the energy of the motion of the particles 124) Gravitational Energy – a star is bound together by gravity 125) Theoretical Approach – the study of stellar evolution a) Calculations are made from theory about how stars should change as they contract gravitationally or age 126) Observational Approach – stars and groups of stars are observed in their evolution 127) Giant – a star of large luminosity and radius a) Supergiant is a star of very high luminosity a.i) Less than 1% of the stars on the H-R diagram are giant or supergiant 128) Absolute Magnitude – the indicator of the star’s luminosity a) Which is the brightness of a star seen from a distance of 10 parsecs, or 33 light years 129) Albedo – the fraction of incident light that is reflected by a body a) Moon albedo is .07, which means that it reflects only about 7% of the light from the sun, and absorbs most of the sunlight 130)
Image of page 12
Image of page 13
This is the end of the preview. Sign up to access the rest of the document.
  • Winter '12
  • None

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern