Calculate the distance to 61 cygni in meters and parsecs.

7) Friederich Bessel suspected that the star 61 cygni, scarcely visible with the naked eye, might be one of our closest neighbors. He was able to measure the total angular shift of 61 cygni, arising from the earth’s orbital motion, as 0.628 arc seconds. Taking the average distance of the earth from the sun as 149.6 million km, calculate the distance to 61 cygni in meters and parsecs.

Calculate the distance of this star.

8) Sirius is one of our nearest and brightest neighbors at a distance of 2065 pc. By a careful comparison of the spectral lines, a second star is known to have an intrinsic brightness, or luminosity, very similar to that of Sirius, even though it appears one hundred times fainter from earth. Calculate the distance of this star.

Work out its distance from earth, taking Hubble’s constant to be 71 km s -1 Mpc -1.

9) A galaxy has a red-shift measured as 0.21. Work out its distance from earth, taking Hubble’s constant to be 71 km s -1 Mpc -1.

The AMANDA neutrino telescope

10) The AMANDA neutrino telescope was mentioned in Reference below. The neutrinos it detects have passed through the earth and are rising through the ice sheet. There are an enormous number of neutrinos doing this every second. A tiny proportion of these interact with quarks within protons or neutrons in the ice to form muons. There are three generations of neutrino, state which kind of neutrino will interact in the way described, and give its symbol. (Reference: The AMANDA 677 photon multiplier tubes embedded within the polar ice sheet to depths of over 2km. These tubes use the photoelectric effect to detect light. The metallic light-receiving surface within each tube is sensitive to li... click for more

Neutrinos

11) Suppose that one of the neutrinos (in Reference below) interacts with a down quark and the outcome is one muon plus one up quark. (i) Which of the four fundamental interactions is involved in this process? List the conservation laws that apply. (ii) Identify a quantum of energy which might facilitate the interaction. (iii) Draw a Feynman diagram to represent the interaction. Reference: I have obtained an answer for the following question. 10) The neutrinos that AMANDA neutrino telescope detects have passed through the earth and are rising through the ice sheet. There are an enormous number of neutrinos doing this every second. A tiny proportion of these interact with quarks within... click for more