Astronomy | Astrophysics Answers

A passenger on a cruise liner celebrates his birthday one evening with a party. It is June 18th. The ship is in zone −12 and at zone time 23h 36m, June 18th, it crosses the date line. Show that the passenger may legitimately have another birthday party for the same birthday.

A star of declination 42◦ 21` N is observed when its hour angle is 8h 16m 42s. If the observer’s latitude is 60◦ N, calculate the star’s azimuth and altitude at the time of observation.

The zenith distances of a star at upper culmination (south of the zenith) and lower culmination are 24◦ and 74◦ respectively. Calculate the latitude of the observer and the declination of the star.

A plane, moving with a speed of 500 knots, flies the great circle route from Prestwick (4◦ 36` W, 55◦ 30` N) to Gander (54◦ 24` W, 48◦ 34` N).What distance does it cover and how long does the flight take?

A distant quasar is observed to have a redshift v/c = 0.15, where v is the
recession velocity of the quasar, and c = 300, 000 km/s is the speed of light.
(a) What is the recession velocity v of the quasar in units of km/s? (2 points)

A. 7.47 × 10−5 km/s
B. 45,000 km/s
C. 0.059 km/s
D. 1.43 km/s
E. 1.97 × 106 km/s

(b) What is the luminosity L of Altair in units of the solar luminosity L⊙? (4 points)

An astronomer observes a bright star (Altair) that has a parallax angle of
p = 0.20 arcseconds. The flux f from Altair is approximately 9.4 × 10−12 times the flux
from the Sun. The distance d from the Earth to the Sun is (1/206265) pc.
(a) What is the distance d to Altair star in units of parsecs (pc)? (2 points)


A. 0.20 pc
B. 2.06 pc
C. 3.14 pc
D. 5 pc
E. 50 pc

Problem: 3. Our neighbor galaxy, Andromeda, has a luminosity (intrinsic brightness)
3 times as bright as the Luminosity of our Milky Way galaxy, LAndromeda = 3LMW, and
is at a distance of dAndromeda = 0.7 Mpc. The flux we observe from the Andromeda
galaxy (apparent brightness) is 10,000 times brighter than the flux observed from a distant
quasar, fAndromeda = 104fquasar. This quasar has a luminosity that is 1000 times the
luminosity of our Milky Way galaxy, Lquasar = 103LMW. What is the distance d to the
quasar? (4 points)

A. 1.28 × 10−1Mpc
B. 3.85Mpc
C. 1.28 × 103Mpc
D. 2.36 × 106Mpc
E. 3.85 × 1012Mpc

(ii) Assuming the energy released during core bounce and supernova phase of this neutron
star was 2 MeV per neutron, calculate the total energy output of the supernova in
ergs. Note that 1 MeV = 1.6 × 10−6 ergs. (2 points)

A. 1.5 × 1063 ergs
B. 3.8 × 1051 ergs
C. 7.7 × 1051 ergs
D. 7.7 × 1057 ergs
E. 4.8 × 1057 ergs