ly
Abbreviation with 2 meanings
| Stands for | Light-year |
|---|---|
| Meanings | 2 |
| Categories | Science & Engineering, Geography & Places |
| Also written | LY |
ly has two meanings. It stands for Light-year (astronomy & Space) or Libya (country code).
Meanings of ly at a glance
| # | ly stands for | Context |
|---|---|---|
| 1 | Light-year | Science & Engineering › Astronomy & Space |
| 2 | Libya | Geography & Places › Country Code |
1. Light-year
Science & Engineering · Astronomy & Space Abbreviations · also used in measurement
Distance light travels in a vacuum in one Julian year, about 9.46 trillion kilometers (5.88 trillion miles). Light-years express distances to stars and galaxies: the nearest star beyond the Sun, Proxima Centauri, is about 4.24 ly away, and the Milky Way is roughly 100,000 ly across.
Example: The Andromeda Galaxy lies about 2.5 million ly away, so we see it as it looked 2.5 million years ago.
Despite the word "year," a light-year measures distance, not time, a frequent error in advertising and fiction. Professional astronomers prefer the parsec (about 3.26 light-years) in research papers. The IAU defines the year used as exactly 365.25 days.
2. Libya (LY)
Geography & Places · Country Code Abbreviations
Libya, capital Tripoli, alpha-3 LBY, has Africa's largest proven oil reserves. Its .ly domain became famous through link shorteners such as bit.ly, which used it because many English adverbs end in -ly.
Example: The bit.ly link actually resolves through the LY registry in Tripoli.
Libya has been divided between rival governments for much of the period since 2011, at times disrupting the registry. The Libyan dinar is LYD.
Related abbreviations
More astronomy & Space abbreviations
- LEO – Low Earth orbit
- LISA – Laser Interferometer Space Antenna
- LOX – Liquid oxygen
- LSST – Legacy Survey of Space and Time
- M – Messier object
- MACHO – Massive compact halo object
- MECO – Main engine cutoff
- MEO – Medium Earth orbit
See all 83 astronomy & Space abbreviations →