Andromeda Constellation
Andromeda (The Chained Maiden)
Andromeda is a prominent constellation in the northern sky, named after the mythological princess Andromeda. Known for its beauty and rich astronomical features, the constellation is home to the famous Andromeda Galaxy, the nearest spiral galaxy to the Milky Way. Andromeda is best viewed in autumn in the Northern Hemisphere.
Key Features
- Bright Stars: Andromeda contains several notable stars:
- Alpheratz (Alpha Andromedae): The brightest star in the constellation, shared with the neighboring constellation Pegasus. It is a blue-white star located about 97 light-years away.
- Mirach (Beta Andromedae): A red giant star located approximately 197 light-years away, often used as a guide to locate the Andromeda Galaxy.
- Almach (Gamma Andromedae): A beautiful double star system with contrasting colors of yellow and blue, located about 350 light-years away.
- Deep-Sky Objects: Andromeda is rich in celestial wonders:
- Andromeda Galaxy (M31): The largest and brightest galaxy visible from Earth, located 2.5 million light-years away. It is on a collision course with the Milky Way, set to merge in about 4.5 billion years.
- Messier 32 (M32): A small satellite galaxy of the Andromeda Galaxy.
- Messier 110 (M110): Another satellite galaxy of Andromeda, featuring subtle details visible in larger telescopes.
- NGC 891: A stunning edge-on spiral galaxy located near the border of Andromeda.
Mythological Background
In Greek mythology, Andromeda was the daughter of King Cepheus and Queen Cassiopeia of Ethiopia. Cassiopeia’s boast that her daughter was more beautiful than the sea nymphs angered Poseidon, who sent a sea monster to ravage their kingdom. To appease Poseidon, Andromeda was chained to a rock as a sacrifice but was rescued by Perseus, who used Medusa's severed head to turn the monster to stone.
To honor their story, Andromeda, along with Perseus, Cepheus, and Cassiopeia, was placed in the sky by the gods.
Cultural Significance
The Andromeda Galaxy is one of the most studied celestial objects and is a popular target for amateur and professional astronomers. Its proximity and size make it a key feature in understanding galaxy formation and evolution.
The constellation’s mythological story and its role in guiding stargazers to the Andromeda Galaxy have cemented its place in both astronomical and cultural traditions.
Andromeda Rise and Set Timetable
| Time | Elevation | |
| Moon Rise, 12.2% illuminated | 09:25 | 71° |
| Astrosession begin | 22:19 | -2° |
| Andromeda Rise | 22:41 | |
| Moon Set | 23:48 | 8° |
| Astrosession end | 04:52 | 58° |
| Civil sunrise | 05:33 | 66° |
| Sunrise | 06:07 | 72° |
| Andromeda Transit | 07:39 | 90° |
Track Andromeda Position Throughout the Night
← Sun, 29 June 2025 →
| Time | 02:19 |
| Altitude | -2° |
| Azimuth | -29° |
Annual motion of Andromeda
| Date | Sun, 29 June 2025 |
| Twighlight start | 23:02 |
| Twighlight end | 03:58 |
| Twighlight duration | 5h 55m |
| Rise | 22:41 |
| Set | 16:38 |
| Elevation at transit | 90° |
| Transit time | 07:39 |
| Equatorial coordinates | RA: 00h 39m 08s", Dec: 40° 11' 33s |
| Magnitude | - |
| Constellation |
The graph is structured with the vertical axis showing the hours of the day, ranging from 12 AM to 12 AM the next day, while the horizontal axis spans each day of the year.
The reddish shaded area indicates the periods when the Andromeda is above the horizon, visible to observers. The white line marks the times when the celestial object reaches its highest point in the sky each day, known as the transit.
Acknowledgements
We gratefully acknowledge the International Astronomical Union (IAU) for defining and standardizing the official constellation boundaries, which provide a consistent framework for celestial mapping.
Special thanks to Sky & Telescope Magazine and contributors Roger Sinnott and Rick Fienberg for their collaboration in producing the charts and tables. The constellation patterns, drawn by Alan MacRobert, were influenced by the work of H. A. Rey and thoughtfully adjusted to align with earlier traditions.