Asteroid 221 Eos Observation Details
Eos Daily Motion
Eos will rise before twilight begins, at 21:15, and will reach 19° elevation by the time twilight commences at 23:06. It will reach its transit at 38° by 02:33 and gradually fade away as the night ends at 04:05, maintaining an elevation of around 34°.221 Eos will be visible until October, 12, when it will move too close to the Sun. During this time, its proximity to the Sun will cause it to disappear from the night sky, making it unobservable for a while.
Eos Visibility Timetable on July 01
Eos Rise and Set Timetable
| Time | Elevation | |
| Moon Rise, 29.5% illuminated | 11:39 | -42° |
| Eos rise | 21:15 | |
| Civil sunset | 21:37 | 4° |
| Astrosession begin | 23:06 | 19° |
| Moon Set | 00:33 | 31° |
| Eos transit | 02:33 | 38° |
| Astrosession end | 04:05 | 34° |
| Civil sunrise | 05:34 | 23° |
| Sunrise | 06:08 | 18° |
| Eos set | 07:51 |
Track Eos Position Throughout the Night
← Tue, 1 July 2025 →
| Time | |
| Altitude | |
| Azimuth |
Shift the map to change the time and observe Eos changing position in the night sky.
Eos Description
Eos, designated as 221 Eos, is a main-belt asteroid, located between Mars and Jupiter in the solar system. With a diameter of 96 km, 221 Eos completes its orbit around the Sun in 5.2 years. At the moment, 221 Eos is 1.8 AU (269,246,248 km) from Earth, and it is located in the constellation Sagittarius.Current position of Eos in Solar System
| Date | Tue, 1 July 2025 |
| Distance from Earth to Eos | 1.7998 AU (269,246,248km) |
| Elongation | 162° |
| Angular diameter | " |
| Magnitude | 11.8 |
Finder Chart for Eos
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| Object name | 221 Eos |
| Field of view | |
| Limiting magnitude | |
| 221 Eos coordinates | 19.65889, -12.08078 |
| Center coordinates | 19.65889, -12.08078 |
Annual motion of Eos
| Date | Wed, 2 July 2025 |
| Twighlight start | 23:05 |
| Twighlight end | 04:04 |
| Twighlight duration | 5h 58m |
| Rise | 21:11 |
| Set | 07:46 |
| Elevation at transit | 38° |
| Transit time | 02:28 |
| Equatorial coordinates | RA: 19h 38m 48s", Dec: -12° 08' 51s |
| Magnitude | 12 |
| Constellation | Sagittarius |
The graph illustrates the annual visibility pattern of a Eos, providing a comprehensive overview of its daily appearances and transit times throughout the year.
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 Eos 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.
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 Eos 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.
Acknowledgments
We acknowledge NASA's Jet Propulsion Laboratory (JPL) for providing essential data on asteroids and comets through their Small-Body Database (SBDB) and Center for Near-Earth Object Studies (CNEOS). Their continuous efforts in tracking and cataloging these celestial bodies make it possible to offer accurate and up-to-date information on their positions, orbits, and physical characteristics.