| Minorplanet: | yes |
| 697402 Ao | |
| Background: |
|
| Discovery Ref: |   |
| Discoverer: | COIAS |
| Discovery Site: | Maunakea |
| Discovered: | 23 January 2017 |
| Mpc Name: | (697402) Ao |
| Named After: | |
| Orbit Ref: |   |
| Epoch: | 31 March 2024 (JD 2460400.5) |
| Uncertainty: | 0 |
| Observation Arc: | 6654 days |
| Perihelion: | 2.940 AU |
| Semimajor: | 3.229 AU |
| Eccentricity: | 0.0895423 |
| Period: | 5.8 yr |
| Mean Motion: | / day |
| Inclination: | 8.94156° |
| Asc Node: | 190.52888° |
| Arg Peri: | 78.85772° |
| Abs Magnitude: | 17.09 |
(697402) Ao, provisional designation, is an outer main-belt asteroid. It was discovered on 23 January 2017, by the citizen science project Come On! Impacting ASteroids (COIAS) using archival data from the Subaru Telescope, which was first reported to the Minor Planet Center in February 2024.[1]
Ao is an Outer Main-belt Asteroid in a heliocentric orbit with a semi-major axis of about 3.2 AU in a relatively circular orbit with an eccentricity of 0.09 and an inclination of about 9 degrees. It orbits the Sun every 5.8 years.
The first observation of Ao was on 25 March 2006 by Mt. Lemmon Survey. The asteroid was also observed and reported in later years, however, only in late 2016 and 2017, it has been observed for multiple nights in a single opposition, which is how the Minor Planet Center determines the discovery opposition. However, these observations made using Subaru Telescope were not reported until February 2024 through the web-based citizen science project Come On! Impacting ASteroids (COIAS). Between years 2017 and 2024, other observations were also made, none of which provided multiple night observations in a single opposition. Multiple astrometric measurement reports through the COIAS project belonging to observations dated 2017 therefore became the earliest reports of multiple-night observations of the asteroid within a single opposition, determining the discovery observations. The asteroid was located in these images by using a digital blinking and moving object detection method.
After the astrometric measurements belonging to 2017 observations were identified to belong to the same object, a provisional designation was assigned to the object. After its orbital uncertainty parameter dropped to 0, the asteroid was numbered (697402) and the discovery credit was assigned to Subaru Telescope and later to the citizen science project COIAS.
For the naming of the asteroid, the COIAS development team and the citizen scientists who have taken part in the astrometric measurements of (697402) has made a discussion.[2] It was decided to name the asteroid after the fictional character Ao Manaka, who appears as a main character in the comic/animation Asteroid in Love created by author Quro. This decision is explained in the naming citation as follows:
Ao Manaka is a character in the comic/animation Asteroid in Love created by Japanese manga artist Quro. Ao and her friends enjoy Earth Science Club activities in their high school with a dream of naming an asteroid “Ao.” The work encouraged many readers to study Earth and planetary sciences with its accurate depiction of celestial objects and geology.