(164207) 2004 GU9

(164207) 2004 GU₉

2004 GU9 photographed by the Canada–France–Hawaii Telescope in February 2007
Discovery[1]
Discovered by	LINEAR
Discovery site	Lincoln Lab's ETS
Discovery date	13 April 2004
Designations
Minor planet category	NEO · Apollo
Orbital characteristics[2]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 0
Observation arc	5424 days (14.85 yr)
Aphelion	1.1376258581 AU (170.18640603 Gm)
Perihelion	0.86490477 AU (129.387912 Gm)
Semi-major axis	1.001265315 AU (149.7871591 Gm)
Eccentricity	0.1361882
Orbital period (sidereal)	1.00 yr (365.95 d)
Mean anomaly	154.915171°
Mean motion	0° 59^m 1.464^s / day
Inclination	13.6490265°
Longitude of ascending node	38.6405971°
Longitude of perihelion	280.55672±0.00007°
Time of perihelion	2456145.53817±0.00006 jd
Argument of perihelion	280.28542°
Earth MOID	0.000389702 AU (58,298.6 km)
Physical characteristics
Mean diameter	160–360 meters[3]
Geometric albedo	0.219
Absolute magnitude (H)	21.1[2]

(164207) 2004 GU₉ is a sub-kilometer asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. It will be a quasi-satellite of Earth until around 2600.^[4]

On 14 April 2004 (with less than a 1-day observation arc), the Sentry Risk Table showed 180 virtual impactors.^[5] It was removed from the Sentry Risk Table 2 days later on 16 April 2004.^[6] (164207) 2004 GU₉ now has a well determined orbit with an observation arc of 12 years.

Discovery and naming

This asteroid was discovered on 13 April 2004 by the Lincoln Near-Earth Asteroid Research project near Socorro, New Mexico and given the provisional designation 2004 GU₉.^[1] Following the naming of 524522 Zoozve, a quasi-satellite of Venus, Radiolab and the International Astronomical Union will hold a public naming campaign for this quasi-satellite from June to September 2024. The selected name will be announced in January 2025.^[7][8]

Animation of (164207) 2004 GU9's orbit from 1600 to 2500

Relative to Sun and Earth

Around Earth

Around Sun

   Sun ·    Earth ·   2004 GU9

See also

• (277810) 2006 FV35

References

1. "(164207) = 2004 GU9". Minor Planet Center. Retrieved 3 June 2024.
2. "(164207) 2004 GU9". JPL Small-Body Database. Jet Propulsion Laboratory. SPK-ID: 2164207. Retrieved 7 April 2016.
3. "Absolute Magnitude (H)". NASA/JPL. Archived from the original on 2 March 2001.
4. Wajer, Paweł (October 2010). "Dynamical evolution of Earth's quasi-satellites: 2004 GU9 and 2006 FV35". Icarus. 209 (2): 488–493. Bibcode:2010Icar..209..488W. doi:10.1016/j.icarus.2010.05.012.
5. "Major News about Minor Objects: Risk monitoring". hohmanntransfer. 14 April 2004. Archived from the original on 6 November 2020. Retrieved 2 March 2015.
6. "Date/Time Removed". NASA/JPL Near-Earth Object Program Office. Archived from the original on 2 June 2002. Retrieved 1 March 2015.
7. "Competition Announced to Name a Quasi-Moon". IAU. 31 May 2024. Retrieved 3 June 2024.
8. "OFFICIAL RULES: Name a Quasi Moon!". Radiolab. Retrieved 3 June 2024. Radiolab is partnering with the International Astronomical Union to launch a months-long global naming contest for one of Earth's quasi-moons (asteroid 164207).

External links

• Dynamical evolution of Earth’s quasi-satellites: 2004 GU9 and 2006 FV35 by Wajer, P. 2010, Icarus, Volume 209, Issue 2, pp. 488–493.
• (164207) 2004 GU9 at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemerides · Observation prediction · Orbital info · MOID · Proper elements · Observational info · Close approaches · Physical info · Orbit animation
• (164207) 2004 GU9 at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical properties · Summary
• (164207) 2004 GU9 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters