The appearance of the great rane ;c80xhn 8 jwjmfg5b8ge of brightness among stars is due to

  The absolute luminosity for 3+dorviy(dx 5 most stars depends on the

  Four different main-sequence stjz, hcbe-:,b iars are colored blue, orange, red, and yellow. What is their ran-cj,ie:bb, zhk from coolest to hottest?

  A Hertzsprung-Russell diagr:lyv x,j5:kuihn)9p nam shows stars on a plot of

  A white dwarf star with a mass equal to that of the n h/sgdz vk/(7m16zmc Sun is about the size of

  The Chandrasekhar limit of stella1u3 b re+mjrp3r mass (below which a star will collapse into a white dwarf) is, i1 jrbu33ep+ mrf the mass of our Sun is M, about

  Supernovas are thought to alwa4n vpl bl5 :8il(gcek-ys result in

  Black holes

  Pulsars are rapidly spinnings,yws i,4v(g qlhu2 h35 r3fuf

State Einstein's principle of equq.s+i) vff+ug ivalence.

  The Schwarzschild radius of a black hole is that radial distae/f/gl j( eaz3l.g+k cnce from the center of a sphere within which not even light can escape. It was first de/+e claflj k3/z(gg. iscovered mathematically 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 partg.tj 83* pgl,.2arch66dv f mz 1djovdicular wavelength in the visible, and the source is moving away from us, the cd j*cmgj l v6h .zp1,gt26.dv8od3fa rolor of the light appears to us to be shifted toward the

  The cosmic background radiation corresponds to a temperatuweyqrr10n, bje94i( alhe: i.re of about

  The Sun has apparent bright(a ss6:uhxdz 5:l(t:7: k ivlpv7jrij ness 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 2 k55nr nf,pwzthe 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 hasc 0m 1h-(yzwmg 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 rt9ku(xncl s6n( *b 8lguy(r 2mean 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 fw quell8 f3cb0/5j(0 (64 xisnocwstis Earth's nearest star at 4.3 ly?fsw4 6b0(unfce5/0 otl x c3wjls(8iq

  The apparent brightness )w *wmsqky:.nof a 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 appro n27 v2 4zi+qzfj6tcq;zwx o7rdx3e/ hximate age of the universe is 1/H, where H is the Hubble constant. Taking H = 20 km/s/Mly, estimate the age of the univers+oz7jqd7 4w2 ;v2ir63zn /xhqzce tfx e, in years.

  If a galaxy is moving away from us1g:t:/xkj b6+ x ttjhi at 1.0% of the speed of light, how far away is it frohijx tj/k1+xg: 6: tbtm us?

  Estimate the speed of a galaxy thi/ y7t.xr4 al8btt+wa;e qov ;at is 10 billion light-years away.

  Estimate the observed wavelength for the 656 nm line in the spe7j9 ns1nyipd a0m wm1;ctrum of a star which is s01dnymn ;mpj917w ai 100 million light-years from us.

  About 1 ms after the Bigllo/x59a/dkkii. 7; q/tjz fi Bang, the temperature of the universe was about 1013 K. What energy (in eV) does this corresa5kk9 jloi/q /itxz /f7 dl;i.pond to?