Gemini Constellation
Gemini (The Twins)
Gemini is a prominent constellation in the northern sky, representing the mythological twins Castor and Pollux. It is one of the 13 ecliptic constellations and is easily recognizable by its two bright stars, named after the twins themselves. Gemini is rich in both mythological significance and astronomical features, making it a favorite among stargazers.
Key Features
- Bright Stars: Gemini’s two brightest stars mark the heads of the twins:
- Deep-Sky Objects: Gemini contains several notable celestial objects:
- Messier 35 (M35): A large and bright open star cluster located near the feet of the twins.
- Eskimo Nebula (NGC 2392): A planetary nebula resembling a face surrounded by a parka hood.
Mythological Background
In Greek mythology, Gemini represents the twin brothers Castor and Pollux, the sons of Leda. Castor was mortal, while Pollux was immortal, being the son of Zeus. When Castor died, Pollux pleaded with Zeus to reunite them, leading to their placement among the stars as the constellation Gemini. Their story symbolizes brotherly love, loyalty, and sacrifice.
The constellation also features prominently in Roman and other ancient myths, often as symbols of companionship, strength, and duality.
Cultural Significance
Gemini has been an important constellation for navigation and timekeeping. Its rising and setting times have historically been used to mark seasonal changes. The twins’ association with sailors made them a symbol of protection and guidance during maritime journeys.
Gemini Rise and Set Timetable
| Time | Elevation | |
Moonrise, 39.4% illuminated  | 11:55 | 42° |
| Moonset | 21:31 | -29° |
| Astronomical observing session begins | 23:57 | -12° |
| Gemini rise | 01:09 | |
| Astronomical observing session ends | 03:28 | 26° |
| Civil sunrise | 04:01 | 33° |
| Sunrise | 04:29 | 38° |
| Gemini transit | 08:18 | 74° |
Track Gemini Position Throughout the Night
← 20 August 2026 →
| Time | |
| Altitude | |
| Azimuth |
Nebulae in the constellation Gemini
M35
Open Cluster
Annual motion of Gemini
| Date | Fri, 21 August 2026 |
| Twilight start | 19:23 |
| Twilight end | 02:48 |
| Twilight duration | 7h 25m |
| Rise | 01:06 |
| Set | 15:23 |
| Elevation at transit | 74° |
| Transit time | 08:14 |
| Equatorial coordinates | RA: 07h 07m 16s", Dec: 21° 31' 49s |
| Magnitude | - |
| Constellation |
The vertical axis shows the hours of the day, while the horizontal axis spans the days of the year.
The reddish area marks when the constellation is above the horizon. The white line shows when it reaches its highest point in the sky. View detailed visibility information in a table with rise, transit, and set times for each date.
Acknowledgements
We gratefully acknowledge the International Astronomical Union (IAU) for defining and standardizing the official constellation boundaries used in celestial mapping.
Special thanks to Sky & Telescope Magazine and contributors Roger Sinnott and Rick Fienberg for producing the charts and tables. Alan MacRobert’s constellation patterns were influenced by the work of H. A. Rey and adjusted to align with earlier traditions.