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A key observational parameter of stars is their distance. What is the best method you could
use to determine the distance to:

a. α Centauri (distance: 1.3 pc).
b. a globular cluster in the Milky Way (distance: ∼ 8 to 30 kpc).
c. an M0 Ia supergiant (distance: 5 kpc).

d. the Hyades open star cluster (distance: 46.3 pc).

e. a spiral galaxy in the Fornax cluster (distance: 17.2 Mpc).

f. the Large Magellanic cloud (distance: 48.5 kpc).

Motivate your answers.
Cygnus A is one of the brightest radio galaxies in the extragalactic sky. The figure below
shows the spectral energy distribution of Cygnus A over a wide range of frequencies across
the electromagnetic spectrum.

a. What can you say about the nature of the radiation of Cygnus A at low frequencies?
b. Use the figure below to calculate the spectral index (α) of Cygnus A at a radio frequency
of 1400 MHz. Hint: F(ν) = F0ν^−α

The Pinwheel Galaxy (M33, also called the Triangulum Galaxy) is a nearby (D = 690 kpc)
nearly face-on Sc-type spiral galaxy.

a. How many parsecs in M33 correspond to an angular size of 100 as seen from the Earth?
b. If the rotation curve is like our Milky Way (see your notes in Section 13), what is the
revolution period for a star 10 kpc from the galactic centre of M33?
c. What is the velocity of the star in b. in parsecs per year?
d. How far in arcseconds would the star appear to move in 100 years?
e. If astronomers can measure positions with an accuracy of 0.0100, comment on how long it
would take before the proper motion of the star in M33 could be readily detected
From home plate to the center field wall at a ball park is 130 meters. When a batter hits a long drive the ball leaves his bat 1 meter off the ground with a velocity of 40 meters per second at 28 degrees above the horizontal. The center field wall is 2.6 meters high. Does he hit a home run?
The siriometer is a rarely-used astronomical measure equal to 1 million astronomical units which is 1 million times the average distance between the Sun and Earth. This distance is equal to about 15.8 light years and is about twice the distance from Earth to the star Sirius. How many parsecs is it from our sun to dinner up which is 3228 light years away? 1 pc= 3.262 LY, 1 pc= 206,264.806 AU, 1 AU = 1.496 x 10^11 meters
The crab is defined as the intensity of x-rays emitted from the Crab Nebula at a given photon energy up to 30 kiloelectronvolts (keV). One crab is approximately 24 pW/m^2. What surface area in ft^2 would show the intensity of X-rays in 1 second?
If parallax of a star is 0.1 and three times luminosity than sun, find apparent magnitude
A pilot who is 60km above from sea level watches sun rise at 0546h .At what time observer in below the plane can watch the sun rise?
Build up an equation for increasing wave length when mass of a star is M and radius is R .
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