Which of the following is correct forhk9eo fn/ ft be-//0rr a stable star?

  1.A star X is burning c..xri7blh73;qr wf zy arbon in its core. The reaction is given by:
$^{12}_{6}C$+$^{12}_{6}C$→$^{24}_{12}​Mg$
The following data are available for the reaction.
Rest mass of the$^{12}_{6}C$= 12.0111507u
Rest mass of the$^{24}_{12}​Mg$= 23.9909630u
Determine, in MeV, the energy released in the reaction. Be sure to express your answer to the correct number of significant figures. $ΔE$ =    MeV
2.The star Y is a red supergiant. State the next steps in the evolutionary sequence of the star Y.
3.Outline why the sun is not expected to undergo carbon fusion.

  Which of the following is cy94ut.qev8h e wdkrb yuh /*/4orrect about a red giant star?
I. The orbits of the inner planets of the solar system and could fit into the volume of it
II. Cooler than the Sun
III. Have higher luminosity than the Sun

  1.VV Cephei is a binary stary*)xy0a: +m/sm,(vw o zknka/ -0.yqm qb mzvp system composed of two stars referred to as VV Cephei A and VV Cepq zx:.-msy 0kn0v)kv*oyam /qz+am/bp(m,w yhei B.
(1)The measured wavelength of the peak spectral line of VV Cephei A is 760 nm. Show that the surface temperature of VV Cephei A is approximately 3800 K. T =    K
(2)The surface temperature of the Sun is $T_⊙$​=5800 K. The luminosity of the VV Cephei A is $2.7\times10^5$ times the Sun's luminosity $L_⊙$​. Determine the radius of VV Cephei A in terms of the Sun's radius $R_⊙$​. R =    $R_⊙$​
3.A Herzsprung-Russel (HR) diagram is shown.


Plot the current position of VV Cephei A on the HR diagram and identify the classification of VV Cephei A.
2.The mass of VV Cephei B is about 11 times the mass of the Sun and it is not on the main sequence.
(1)In terms of forces, explain the condition that causes a star to first leave the main sequence.2
(2)Explain why VV Cephei B is likely to remain on the main sequence for a shorter time than the Sun.2
(3)The parallax angle for VV Cephei B is 0.31 arcseconds. Calculate, in light years, the distance between the earth and VV Cephei B.2. d =    ly
(4)State why the parallax method is not suitable for measuring the distance of very distant stars.

  A main sequence star has a mass greateawzp2(6 *lw wzul:u u(r than 4 times the mass of the Sun. Which of the following is correct about th6(luzluw2( az:*pw w ue possible the fate of the star?
I. White dwarf
II. Neutron star
III. Black hole

  A star with a mass of twice th49iyc. ( v1nt(n)fc8kitwn/*gpi , cz9oyglne mass of the sun is a main sequence star. The time the sun is expected to spend in the main sequence is T. Which of the following is correct for the time the star is expected to speng 9c*yflygc9t cv(8(on4.w ,tiznn 1)ip /nikd in the main sequence and the next stage in its evolution?

  In the core of a star, a proton-p,0 ii fo w,5x96ayoo z-zpu;suroton chain reaction takes place.
$4^1_1​H$→$^4_2​He$+$2^0_{+1}​β^+$+$2\,ν_e$​+$2\,γ$
After the initial stage of the reaction, two positrons annihilate with electrons present in the surroundings. Which of the following correctly shows the nature of the chain reaction and the energy released due to annihilation?

  The parallax angles of Star A and Star B are 0.2507li.4v;c2 jirz7oxy e arcseconds and 0.500 arcseconds le xz4 jiryvo2;77i.c respectively. What is the shortest possible distance, in parsec, between Star A and Star B?

  A star with a mass similar to the Sun, a temperat4hfl t5syp/muud-avb o ;(r90ure hotter than the Sun, and a radius similar to the Earth would be found in which region of the usual Hertzsprung-Russell diagram?0o-9uhm /uspybtvl4 5a(d ;fr

  The luminosity of the Sun iu 20;ib(fm a.0gh;fpgfs.p jzr yrt7p95bvp0s $L_⊙$​. A main sequence star with twice the radius of the sun and twice the temperature of the sun has a luminosity of $L$. What is the ratio of $\frac{L}{⊙​L}​$ ?

  Some regions on the H-R diagram are l ol oxti449c4xabelled.

A main sequence star with a mass of three times the Sun will evolve through a series of stages. Which of the following sequences of stages could correctly represent the path of the evolution of this star?

  For fusion reactions to occur in a cloud of ste )jx 4/ovqfb.c3xai nf,:uh.i llar dust, a combination of high temperature and high density among hydrogen nuclei is essenti)h i4x 3o/nj.v. afb:i,fux cqal. Which of the following correctly shows why high temperature and high pressure are needed?