2020年GeCAA理论第7题-流星雨辐射点

英文题目

A stargazer in Chiayi, Chinese Taipei (23.5°N, 120.4°E, GMT+8) saw two meteors streaking through the sky at 21:00 (Chinese Taipei time) on 25th September 2020. One of the meteors appeared at horizon exactly due west and streaked to a point at 15° altitude directly above the northern horizon. The second meteor originated at an altitude of 23.5° and an azimuth of 210° and ended at an altitude of 75° and an azimuth of 255°.

(a) (6 points) What is the Local Sidereal Time (LST) at the time of observation?

(b) (16 points) Find the alt-az coordinates of the apparent radiant of the two meteors.

(c) (6 points) Find the equatorial coordinates of the apparent radiant.

(d) (2 points) Which of the following constellations is closest to the radiant?

Crux / Dorado / Pavo / Tucana / Triangulum Australes

(choose one and write the same name in the answer box)

Notes:

• Azimuths are measured from the North (0°) towards the East.

• The Greenwich Sidereal Time (GST) at 00:00 UT on 1st January 2020 is 6h 40m 30s.