Pulsars - Study guides, Class notes & Summaries

 -1.5 magnitude Sirius appears 25x brighter than 2 magnitude Polaris.  “All neutron stars are pulsars, but not all pulsars are neutron stars” FALSE  “Spectroscopic Binary” is the term given to a pair of stars that we can determine are orbiting each other only by measuring their periodic Doppler shifts.  A 6.8 solar mass neutron star does NOT exist.  A loop of gas and charged particles following the magnetic field lines between sunspot’s poles is a Prominence/...

ASTRO 205 (Quasars, Black Holes and Pulsars) Midterm 1 Test Questions and Answers

White Dwarf "Star" correct answers Result of the death of a low mass star The exposed core of a low mass star; -hot -dense -mostly carbon If there is no new energy production in a white dwarf, what prevents gravity from crushing it? correct answers Electron degeneracy pressure White dwarf "stars"- electron degeneracy pressure correct answers Electron degeneracy pressure will only hold up a star to about 1.4 solar masses, above that gravity will begin to win, resulting in the st...

White dwarfs: properties - Remaining cores of dead, low mass stars Electron degeneracy pressure supports them against gravity Slowly fade with time Sirius and its hot WD companion White dwarfs with same mass as Sun are about same size as Earth; slowly cooling Typical density 10^6 gram / cubic cm Higher mass white dwarfs are smaller Cannot be more massive than 1.4MSun, the Chandrasekhar limit WDs in binaries: nova, supernova Type I - Mass falls toward white dwarf from binary companion ...

Explain how a white dwarf's observable properties (specifically Luminosity & Temp) change over billions of years if it is left alone, and show how its location would change on an H-R diagram. - •White Dwarfs are low-mass stars, and if they are left alone, they will fade and cool forever. •If mass transfer adds mass to a White Dwarf, it can become, (1) a Nova, or (2) a Supernova Compared to a white dwarf, a neutron star's density is? - •Not all neutron stars are called pulsars becaus...

What observational measurement is required to determine the distance to a Galaxy using Hubble's Law? - ANSWER-Redshift What were the conditions of the early universe? - ANSWER-Hot and very dense True or False: If Light traveled for 5 billion years, then the distance between the two galaxies must have been less than 5 billion light years when the light began its journey because the distances between galaxies are always increasing in the expanding universe - ANSWER-True If our universe is...

What observational measurement is required to determine the distance to a Galaxy using Hubble's Law? - ANSWER-Redshift What were the conditions of the early universe? - ANSWER-Hot and very dense True or False: If Light traveled for 5 billion years, then the distance between the two galaxies must have been less than 5 billion light years when the light began its journey because the distances between galaxies are always increasing in the expanding universe - ANSWER-True If our universe is...

What observational measurement is required to determine the distance to a Galaxy using Hubble's Law? - ANSWER-Redshift What were the conditions of the early universe? - ANSWER-Hot and very dense True or False: If Light traveled for 5 billion years, then the distance between the two galaxies must have been less than 5 billion light years when the light began its journey because the distances between galaxies are always increasing in the expanding universe - ANSWER-True If our universe is...

Explain how a white dwarf's observable properties (specifically Luminosity & Temp) change over billions of years if it is left alone, and show how its location would change on an H-R diagram. - •White Dwarfs are low-mass stars, and if they are left alone, they will fade and cool forever. •If mass transfer adds mass to a White Dwarf, it can become, (1) a Nova, or (2) a Supernova Compared to a white dwarf, a neutron star's density is? - •Not all neutron stars are called pulsars becaus...

A graduate assistant in astronomy needs to measure the mass of a spiral galaxy. Which of the following observations would be important for her to make? - ️️Obtain the speed at which stars or gas near the outer regions of the galaxy are moving around A star whose temperature is increasing but whose luminosity is roughly constant moves in what direction on the H-R diagram - ️️Left A type of star cluster that contains mostly very old stars is - ️️a globular star cluster A white dwarf...