The appearance of the great range of bmmjw 2p d9-x38c,qqdz rightness among stars is due to

  The absolute luminosity for most stari y/lk5y 5+s2 bawc2t fs98hqas depends on the

  Four different main-sequence stars are coloredpk6qd5mzy3v ;g 3r/k j blue, orange, red, and yellow. What is their rank from coolest ;m56dp rky3kjzg 3q /vto hottest?

  A Hertzsprung-Russell diagram shows stars on h 4m( 4(rzv.ijsc5bin a plot of

  A white dwarf star with a mass equal to that of the y8l1 sf-5c j;sqo5- z/kg rjisSun is about the size of

  The Chandrasekhar limit of stellar mass (belops*gcvhskam qz, op+vz 36 )v4xaz;du 06x/;mw which a star will collapse into av ap4xovxzs3 ;6/ga )+p *,zvkm mdqs0hucz;6 white dwarf) is, if the mass of our Sun is M, about

  Supernovas are thought to always resultz+1z3do 5 8wz ;szq8poetod*cr5u k6p in

  Black holes

  Pulsars are rapidly spinr7fy 8inz 4wdcc ja;39ning

State Einstein's principle of equivale 8ry2yu1v6 o.vt6 gb3s9o35n bsmqrnpnce.

  The Schwarzschild radius of a black hole is that radiao s hes qbv1ue215+ak2l distance from the center of a sphere within which not even light can escape. It was first discovered mathematically by Schwa 1+uekbvss1h 522eoaq rzschild 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 wavelen u.l:x/ia nm8lgth in the visible, and the source is movilml ua.nx/ 8:ing away from us, the color of the light appears to us to be shifted toward the

  The cosmic background radiac zczg ykwew3 pphzc,:0n00t.8ht, ,q tion corresponds to a temperature of about

  The Sun has apparent brightness atxt/ne m, ( o7qh3gb0xujy /+hr 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 the kuvhx (t0t4,pSun ($1.5 \times 10^{8} \; km$ 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 of 1v,x mw ;vpoq:xb-q5 k$1.5 \times 10^{8} \; km$. 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 5ew;wxcl 7(n(buecf ,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 ly? (1 ly = $9.46 \times 10^{15} \; m$)

  What is the parallax angle for Proxima Centauri, which is bl4dz k 7qdm5gi(ir cs-s7z* 7Earth's nearest star azkm7-brsgzi75dq4 l( c*sd7 it 4.3 ly?

  The apparent brightnekb3:g )1ink yic 5m-xpe- pfg(ss of 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 approximate age ofmw axnb2(8( ep the universe is 1/H, where H is the Hubble constant. Taking H = 20 km/s/Mly, estimate the age of the universe, in years.w8(2 pm (nbxea

  If a galaxy is moving away from us at 1.0% of th n o2nw7sz7*z rploj,-e speed of light, how far away is itson*lz2 onpz jr, w7-7 from us?

  Estimate the speed of a galaxy that is 10 billion light-years away. -nh/o jbn:ovzlofbu5 +o,9;w

  Estimate the observed wavelength for the 656 nm line in the spectrum of a io ue qk:zdaiq)f+e dj kr;;0 1*;6bzkstar which is 100 million light-years from usijkak;*kzd;i0 e: 1 )qze; 6+rfq ubod.

  About 1 ms after the Big Bang, the temperature of the universe was abo vrq1grvj 6:l;0akp hqb3 l;twt;4o(e ut 1013 K. What energy (in eV) bk qve;603 wg p;q;(jh llr1aovrtt4: does this correspond to?