Question 100Navigation Problems70% to pass
On 23 March your 1600 ZT DR position is LAT 27°16.3' N, LONG 156°48.2' W. You are on course 063°T at a speed of 18.0 knots. Considering their magnitude, azimuth, and altitude, which group includes the three stars best suited for a fix at star time?
AI Explanation
The correct answer is A) Hamal, Rigel, Alphard.
The key factors in determining the best stars for a fix at the given position and time are the stars' azimuth, altitude, and magnitude. Hamal, Rigel, and Alphard are well-suited because they have high altitudes, favorable azimuths relative to the vessel's course, and bright magnitudes that make them easily observable.
The other answer choices do not provide an optimal combination of these factors. For example, Arcturus, Regulus, and Sirius (choice B) may not be as well-positioned in the sky or as bright as the stars in the correct answer.
Related Questions
#98 On 23 July your 1700 zone time DR position is LAT 27°29' N, LONG 129°26' W. You are on course 079°T at a speed of 20 knots. Considering their magnitude, azimuth, and altitude, which group includes the three bodies best suited for a fix at star time?#99 On 22 July your 1759 ZT DR position is LAT 24°50.2' S, LONG 05°16.0' E. You observe an unidentified star bearing 231°T, at an observed altitude (Ho) of 26°10.0'. The chronometer reads 06h 01m 31s and is 02m 15s fast. What star did you observe?#101 On 24 September your 1841 zone time DR position is LONG 129°34.5' E. At that time you observe Polaris with a sextant altitude (hs) of 25°20.8'. The chronometer time of the sight is 09h 38m 12s, and the chronometer error is 03m 12s slow. The index error is 4.3' off the arc, and the height of eye is 52 feet (15.9 meters). What is your latitude by Polaris?#102 On 20 June your 1742 zone time DR position is LAT 24°55.0' S, LONG 8°19.6' E. Considering their magnitude, azimuth, and altitude, which three stars are best suited for a fix at star time?#103 On 30 October an ex-meridian altitude of the Sun's lower limb at upper transit was observed at 1144 ZT. Your DR position is LAT 22°42.0'S, LONG 137°16.0'W, and your sextant altitude (hs) is 80°59.4'. The index error is 2.5' off the arc, and your height of eye is 42.5 feet. The chronometer time of the observation is 08h 46m 15s, and the chronometer error is 02m 12s fast. Find the latitude at meridian transit from the ex-meridian observation.