The appearance of the great range of - /e/ndn 7 31d uq3k*d vc;pk6fgzuyuebrightness among stars is due to

  The absolute luminosity -o(mksr/ilr 0for most stars depends on the

  Four different main-sequence stars are colored blu1e,warw) g96 8dbah1djism m7e, orange, red, and yellow. What is their rank from coolest9 i)j wswrmmh8aae67 1dg b,1d to hottest?

  A Hertzsprung-Russell diagram shows sj 4g;rt4l; mlek+/j titars on a plot of

  A white dwarf star with a mass equal to that of the Sun is ari (6n9cc7j ;g kxfbe4bout the size of

  The Chandrasekhar limit of stellar mass (below which a star will collapse into vc2efopz pn9q ;ine. 81;(fzna white dw;qn ; c8f2fpe1(vz.ipn n oez9arf) is, if the mass of our Sun is M, about

  Supernovas are thought to al-7ea g 9u-q td,zb),pfk.u rzgways result in

  Black holes

  Pulsars are rapidly spinn9mq3 p*k7 sderhrfhlfy01*6 fing

State Einstein's princmv5xw;hmwwn msov *z .1) t7u*iple of equivalence.

  The Schwarzschild radius pvr51jbma x4l,i.tc3 of a black hole is that radial distance from the center of a sphere within which not even light can escape. It was first discovered mathematicallyajx,m 51cbtv r.p4li3 by Schwarzschild in 1916 after Einstein published his general relativity theory. It can be calculated from a star's mass M as: $R = 2GM/c^2$. Take the radius of both stars A and B as the Schwarzschild radius. If the mass of star A is twice as much as the mass of star B, the average density of star A, compared to star B will be

  When a distant source emits rb8wqau( m+.ymse+ )ylight of a particular wavelength in the visible, and the source is moving away from us, the color r(+bmu.s eaq+)w yy8mof the light appears to us to be shifted toward the

  The cosmic background radiair,6j k4 2wp,3 z2(lahmlud1zwp , tyftion corresponds to a temperature of about

  The Sun has apparent brightnessee. c (,c/jbs:9*eh4cw:+jffb ztbmp at Earth ($1.5 \times 10^{8} \; km$ away) of B. What would be the apparent brightness of the Sun at Pluto, which is $6.0 \times 10^{9} \; km$ from the Sun?

  A star has absolute luminosity equal to that of thpz818 hy *(begw; *bvcq7b(ws rwhkw*e Sun ($1.5 \times 10^{8} \; km$ from the Earth) but is 10 pc away from the Earth. By what factor will it appear dimmer than the Sun?

  The Earth's orbit has a mean radius ofjv ezp/uv(62sp1j2 m7yb ;srl $1.5 \times 10^{8} \; km$. Over a six-month period, the apparent position of a particular star varies by $0.00014^{\circ}$ due to parallax. How distant is the star, in km?

  The Earth's orbit has a mti6c .7q;hh,-lkk*zco r4manean radius of $1.5 \times 10^{8} \; km$. Over a six-month period, the apparent position of a particular star varies by $0.00014^{\circ}$ due to parallax. How distant is the star, in ly? (1 ly = $9.46 \times 10^{15} \; m$)

  What is the parallax angle for Proxima Centauri, which 5e 8 oab5lc lyg+tsq9+is Earth's nearest star at 4.3 lyg+l8oya5cb+e sl t9 5q?

  The apparent brightness of a star i)so zyxi23nf: t fqa/8s $1.0 \times 10^{-12} \; W/m^{2}$ and the peak wavelength is 600 nm. Estimate its distance from us.

  It can be shown that the approximate age of the univefu;k:o): mmnc vt2 onqaj y 9m:e0y;+ij)fbe8 rse is 1/H, where H is the Hubble constant. Taking H = 20 km/s/Mly, estimate the age of the univejo92;mm: efo yjtv aq:nf)n) 0k e+y8i;bcum:rse, in years.

  If a galaxy is moving away from us at 1.0% od2dp;1 gix4ci f the speed of light, how far away is it fdciid 4;g1x p2rom us?

  Estimate the speed of a galaxy that is 10 billion light-years away4* a2pw1 8s r-trh3fra9c8mkyxcan 7t .

  Estimate the observed wavelength for the 656 nm line in the spectrum of a star 8wlh-gz(zfcrn i:+x6 which iscr(lwhz:8in6 z -+x gf 100 million light-years from us.

  About 1 ms after the Big Bang, the temperature of the universe w77t 4qyco;vwlas about 1013 K. What eneroc47vwly t7q ;gy (in eV) does this correspond to?