The appearance of the greabxkt( 33: :l 2l.hsl1olomnp)b4 yay mt range of brightness among stars is due to

  The absolute luminosity for most: v.0nxm m.w/xi2autj stars depends on the

  Four different main-sequence h4c6,zopbb tnyf6 34m stars are colored blue, orange, red, and yellow. What is thei4ft b63m pbhzo,y c6n4r rank from coolest to hottest?

  A Hertzsprung-Russell diagram shows2xai; oxoxsrf70 i3+t x1e;-u ooxk /l stars on a plot of

  A white dwarf star with a mass equal to that of the Sun is hv vx,o1h))iie+o f9 1kr ijp dlo-:f;about the size of

  The Chandrasekhar limit of stellar mass (below which a star will collapse int p-qsx.owvrxf j985e4.r ,msgo a whi ,rfj8 g5.ms- prsv xqoe.wx94te dwarf) is, if the mass of our Sun is M, about

  Supernovas are thought to 60h: jblv5o.zhg:hn xalways result in

  Black holes

  Pulsars are rapidly 2 uk rq7( vacm-*q/ury ym2d.uspinning

State Einstein's principley* r ;ddziae+f 0zjl32 of equivalence.

  The Schwarzschild radius of a black hole is that radial distance from the centetqxp sc,w ,d4) s 8gzm6ii 6ac21msasm*z, 6lqr of a sphere within which not even light can escape. It was first discovered mathematsct6 6 xqs6msdaa1z,z,*c,mml4w8) i gspi q2ically 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 light of a particular wavelength in the visibl:-jwnxf/ 1xi-vjx n4we, and the source is moving away from us, the color of the light appears to usw4wnj :ixf/x 1nvj --x to be shifted toward the

  The cosmic background radiation corresponds to a temperature of af6xbq n3d41essk9x 0 pbout

  The Sun has apparent/er6x* w;od*2fjydq t brightness 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 th 15zhg wr)j.j;x:emak at of the 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 hask)7 zdfg*j9qx a mean 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 km?

  The Earth's orbit has a meoj))qh 2qkv0jxw3c (aan 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 is Earth's nearxi hh7ye+agl ;rh+*e -est star at 4.3 ly;r+y + hhxe7agelh *-i?

  The apparent brightness of v:y 4r.9*xozau . ehyaa star is $1.0 \times 10^{-12} \; W/m^{2}$ and the peak wavelength is 600 nm. Estimate its distance from us.

  It can be shown that the approximatc5l+ji;zerx0sfs,y rn 6ssu:kl, 9:be age of the universe is 1/H, where H is the Hubble constant. Taking H = 20 km/s/Mly, estimate the age of t; y+5e c,l0jn rssl6bzr:u ,if:sskx9 he universe, in years.

  If a galaxy is moving away from us at 1.0% of the speed of:cwc4/cfvhz p.;3bq0cs 9h wacz4l 5l light, how far away is it from us zl4q.hp3 9c/4bvlhfww;z s5c0a:cc c?

  Estimate the speed of a galaxy that is 10 billion light-yealk mcw8c l,4*ors away.

  Estimate the observed wavelength for the 656 nm line in the spectrum of a syx gty p*jr1*ho +j4/vtar which is 100 million light-yh1grj4* vtxyo/y p +j*ears from us.

  About 1 ms after the Big Bang, the temperature v(gqw,hm93fq(3 mwrjof the universe was about 1013 K. What energy (in eV) wr,v j3w9q 3gmf( mq(hdoes this correspond to?