| Abbreviation | Definition |
|---|---|
| LAMOST | Large Sky Area Multi-Object Fiber Spectroscopic Telescope |
| LAN | Local Apparent Noon |
| LAT | large area telescope |
| LAYS | Luxurious Astronomical Youthful Sophistication |
| LB | Long Base |
| LBN | Lynds Bright Nebulae |
| LBV | Luminous Blue Variable |
| LBVS | Luminous blue variable |
| LC | Las Campanas observatory |
| LCG | light curve generator |
| LEAG | Lunar Exploration Analysis Group |
| LENA | Low Energy Neutrino Astronomy |
| LFAE | Light Field Attribute Explorer |
| LGRB(s) | long gamma ray burst(s) |
| LGS | Local Group Survey |
| LHA | Local Hour Angle |
| LIC | Local Interstellar Cloud |
| LM | Low Mass |
| LMC | Large Magellanic Cloud |
| LMP | Lunar Module Pilot |