Definition

1. Noun:
   • Astronomical almanac / Ephemeris: A table or book providing the calculated positions of celestial bodies (such as the Sun, Moon, planets, and stars) and other astronomical data (like eclipse timings, moon phases, or sunrise/sunset) for specific dates and times.

Usage Examples

• Noun:
  • Các nhà hàng hải xưa dựa vào lịch thiên văn để định vị trên biển. (Ancient mariners relied on the astronomical almanac to navigate at sea.)
  • Lịch thiên văn cho năm 2024 dự báo hai lần nguyệt thực. (The ephemeris for 2024 predicts two lunar eclipses.)
  • Anh ấy tra cứu lịch thiên văn để biết giờ mọc của sao Kim. (He consulted the astronomical almanac to find the rise time of Venus.)

Advanced Usage

• "Lịch thiên văn hàng hải" (Nautical Almanac): A specialized ephemeris used for celestial navigation at sea.
  • Mọi tàu viễn dương đều phải có lịch thiên văn hàng hải mới nhất. (Every ocean-going vessel must have the latest nautical almanac.)

Variants and Related Words

• Lịch (danh từ): Calendar. The general term for any system of organizing days.
• Thiên văn học (danh từ): Astronomy. The scientific study of celestial objects and phenomena.
• Niên giám thiên văn (danh từ): Astronomical yearbook. Often a more detailed annual publication similar to an ephemeris.

Synonyms

• Ephemeris: A table of data giving the calculated positions of celestial objects.
• Almanac: An annual calendar containing important dates and statistical information, which can include astronomical data.
• Celestial chart / table: A broader term for any map or list of celestial data.

Related Concepts

• Dự đoán thiên văn (Astronomical prediction): The forecast of celestial events, which is the primary function of an astronomical almanac.
• Tọa độ thiên văn (Celestial coordinates): The numerical values (like right ascension and declination) used to pinpoint an object's position in the sky, which are the core data in an ephemeris.