ASTR 1030 Homework Solutions: Celestial Coordinates and Eclipses - Prof. Webster C. Cash, Assignments of Astronomy

Download ASTR 1030 Homework Solutions: Celestial Coordinates and Eclipses - Prof. Webster C. Cash and more Assignments Astronomy in PDF only on Docsity! Answers: Homework #2 ASTR 1030 1. Latitude: Sun is on the celestial equator because it is the equinox. If Sun is 20deg south of the overhead, then you are 20 degrees North. Longitude: The Sun is reaching the meridian two hours later than in Greenwich, so you are 30degrees to the west. You are in the Atlantic west of the Cape Verde islands. Sail East. 2. Waxing quarter moon is on the meridian at sunset (6pm). It takes two hours to move 30 degrees. Time=8pm 3. The Sun moves 24 hours of RA in 12 months. It moves 6hours in three months. On June 22 it will be at RA=6Hrs. 4. Beijing is at 120degrees East (8 hours). Boulder is 7 hours West. Total is that Beijing is 15 hours ahead of us. So Beijing is at midnight, starting June 23. 5. You are at the arctic circle, where the Sun does not quite set on the solstice. Latitude=66.5N 6. Greenwich is 8 hours ahead of LA. So Betelgeuse crosses meridian at 13:00. RA of Sun on September 21 is 12:00. On December 22 it is 18:00. November 10 is halfway between so RA=15Hours. Sun will cross meridian 9 hours after Betelgeuse or 22:00. Subtract 12 and multiply by 15. You are at 150 West. Latitude is 90-72=18. South because the celestial equator appears in the Northern sky. 18S, 150W is near Tahiti. 7. The Earth is 8000 miles in diameter. So is its shadow. The Moon is 2400miles across, so the total eclipse lasts while the Moon travels about 5000miles. The Moon goes 2xPIx240,000miles in a month, or about 50,000miles per day. So, the eclipse should last about a tenth of a day. About two hours max.