On 22 June your 0424 ZT DR position is LAT...

Study

Question 1 of 2066636eea28f7522a1c51ad01

On 22 June your 0424 ZT DR position is LAT 26°18.5' N, LONG 124°18.2' W. You observe an unidentified star bearing 031°T at an observed altitude (Ho) of 49°26.0'. The chronometer reads 00h 23m 24s and is 01m 32s slow. What star did you observe?

Back

Question 1 of 20

66636eea28f7522a1c51ad01

No comments yet

Be the first to share your thoughts!

If the question has a related picture, it will appear here.

🔍 Key Concepts

• Using the chronometer correction (slow/fast) to find the correct Greenwich Mean Time (GMT/UT) of the sight • Relating the DR longitude and GMT to determine Local Hour Angle (LHA) Aries and then the approximate GHA of the star • Comparing the computed computed altitude and azimuth (Zn) of candidate stars with the observed Ho and observed bearing to identify the body

💭 Think About

• How do you correct the chronometer time when it is stated as slow? Once corrected, what is your exact GMT of the observation? • Given your DR longitude is 124°18.2' W, what is your Local Hour Angle of Aries at the time of sight, and how does that help you pick the right star from a star identification table or HO 249/229? • Which candidate star, when you look up its SHA and Dec for the correct date and hour, will give a computed altitude and azimuth that most closely match Ho 49°26.0' and bearing 031°T?

✅ Before You Answer

• Be sure you apply the chronometer correction in the correct direction (a slow chronometer means true time is later). • Confirm you are using the correct date and hour of the Nautical Almanac for GHA Aries and star data (remember 22 June at the correct UT). • Double-check the bearing vs. azimuth comparison: the star’s computed Zn should be close to 031°T within a degree or so.

👋 Hi! I'm Genie, your AI study assistant. How can I help you with this question?

Quick actions

— No credit card needed