Astronomy hw #5 questions

Sirus, the brightest star in the Sky, has a parallax of 0.379 arcsec. what is its distance in parsecs? (Round to the nearest hundredth)

2.64 parsecs

if a star is found directly to the to the right of the Sun on the H-R diagram, what can you conclude about its temperature?

it is cooler than the sun

the sun rotates once every 25 days relative to the stars. the sun rotates once every 27 days relative to earth. why are these two numbers different?

earth moves in its orbit during this time

the energy that is emitted from the sun is produced

in the core, by nuclear fusion

star A is blue and star B is red. they have equal luminosities, but star A is twice as far away as star B. which is hotter?

star A

star A is blue and star B is red. they have equal luminosities, but star A is twice as far away as star B. which star is larger?

star B

sunspots peak every ___ years, a consequence of the ___ year magnetic solar cycle

11; 22

radiation transports energy by moving ___, while convection transports energy by moving ___

light; matter

neutrinos make it out of the sun faster than photons. this means they travel faster than photons

false

some engineers and physicists have been working to solve the world’s energy supply problem by constructing power plants that would convert hydrogen and helium. our sun seems to have solved this problem. on earth, what is major obstacle to this solution?

it is difficult to achieve the temperatures and pressures of the interior of the sun

hydrostatic equilibrium inside the sun means that

radiation pressure balances the weight of outer layers pushing down

sunspots, flares, prominences, and coronal mass ejections are all caused by

magnetic activity on the sun

if a star is found directly above the sun on the H-R diagram, what can you conclude about its luminosity?

it is luminous than the sun

the temperature and density change abruptly at the interface between

the chromosphere and the corona

suppose an atom has energy levels at 1, 3, 4, and 4.3 (in arbitrary units). which of the following is not a possible energy for an emitted photon

2.3

as sunspot appears only 70 percent as bright as the surrounding photosphere. the photosphere has a temperature of approximately 5780 K. Find the temperature of the sunspot. Round to the nearest Kelvin

5287

how long does it take particles in the solar wind to reach earth from the sun (the distance between the sun and earth is about 150 million km) if they are traveling at an average speed of 400km/s? (in days, round to the nearest hundredth 0.00)

4.34

an eclipsing binary system has a primary eclipse (star A is eclipsed by star B) that is deeper (more light is removed from the light curve) than the secondary eclipse (star B is eclipsed by star A). what does this tell you about stars A and B?

star B is larger than star A

star A and Star B are two nearby stars. star A has a parallactic angle 4 times as large as star B’s. which of the following statements is true?

star A is one-quarter as far away as star B

if star A has twice the surface temperature of the sun but has the same luminosity as the sun, the radius of star A must be

1/4

in a high mass star, hydrogen fusion occurs via

the CNO cycle

all the stars in a star cluster are or have the same

age

the evolution of a star primarily determined by its

mass

an object that passes near a black hole

is deflected by the curvature of space-time

the 100 Msun star ETA carinae has had episodes of mass loss during which it lost mass at the rate of 0.1 Msun per year. let’s put that into perspective. the mass of the sun is 2×20