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(163348) 2002 NN4
2002 NN4 orbits between Venus and Mars
Discovery [1]
Discovered by LINEAR
Discovery site Lincoln Lab's ETS
Discovery date9 July 2002
Designations
(163348) 2002 NN4
2002 NN4
NEO · PHA · Aten [1] [2]
Orbital characteristics [2]
Epoch 31 May 2020 ( JD 2459000.5)
Uncertainty parameter 0 [2] · 2 [1]
Observation arc14.16 yr (5,171 d)
Aphelion1.2572 AU
Perihelion0.4956 AU
0.8764 AU
Eccentricity0.4345
300 days
83.774 °
1° 12m 4.68s / day
Inclination5.4177°
259.48°
222.23°
Earth  MOID0.0069  AU (2.69  LD)
Physical characteristics
Mean diameter
14.50±0.03  h [5] [a]
X [3]
20.1 [1] [2] [4]

(163348) 2002 NN4 ( prov. designation: 2002 NN4) is a dark, sub-kilometer near-Earth object and potentially hazardous asteroid of the Aten group that flew by Earth on 6 June 2020. The highly elongated X-type asteroid has a rotation period of 14.5 hours and measures approximately 0.7 kilometers (0.4 miles) in diameter. [2] [6] It was discovered by LINEAR at the Lincoln Laboratory's Experimental Test Site in New Mexico on 9 July 2002. [1]

Orbit

2002 NN4 flew by Earth on 6 June 2020, passing 0.034  AU (5.1 million  km; 13  LD) from Earth. [2] The asteroid had been recovered two days earlier on 4 June 2020. [1] By 11 June 2020, the asteroid had brightened to apparent magnitude 14.4, which is roughly the brightness of Pluto.

Being a member of the Aten asteroids, 2002 NN4 orbits the Sun at a distance of 0.50–1.26  AU once every 10 months (300 days; semi-major axis of 0.88 AU). Its orbit has an eccentricity of 0.43 and an inclination of 5 ° with respect to the ecliptic. [2] It was first observed by the Near-Earth Asteroid Tracking on Palomar Observatory on 2 July 2002, or seven nights prior to its official discovery observation by LINEAR. [1] This asteroid has an Earth minimum orbit intersection distance of 0.0069 AU (1,030,000 km), which corresponds to 2.7 lunar distances (LD). [2]

Physical characteristics

A spectroscopic survey of the small near-Earth asteroid population conducted by European astronomers determined that 2002 NN4 is an X-type asteroid. [3] [6] Because of the objects low albedo (see below), it would be considered a primitive P-type asteroid in the Tholen classification.

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, 2002 NN4 measures (735±243) meters in diameter, and its surface has a dark albedo of (0.030±0.027). [4] (The NEOWISE publication uses the designation G3348 for this asteroid. [7]) In 2016, astronomers using the European New Technology Telescope at La Silla Observatory found a diameter of 613 meters with an albedo of 0.047. [3]: 4 

Rotation period

In August 2016, the first rotational lightcurve of 2002 NN4 was obtained from photometric observations over five nights by Brian Warner at the Center for Solar System Studies ( U82) in California. Lightcurve analysis gave a rotation period of 14.50±0.03 hours with a high brightness variation of 0.74±0.05 magnitude, indicative of a highly elongated shape ( U=3−). [5] [a]

Notes

  1. ^ a b Lightcurve plot of (163348) 2002 NN4, by Brian Warner at the Center for Solar System Studies (2016). Rotation period of 14.50±0.03 hours with a brightness amplitude of 0.74±0.05 mag. Quality code is 3−. Summary figures at the LCDB and CS3 websites.

References

  1. ^ a b c d e f g "163348 (2002 NN4)". Minor Planet Center. Retrieved 8 June 2020.
  2. ^ a b c d e f g h "JPL Small-Body Database Browser: 163348 (2002 NN4)" (2016-08-28 last obs.). Jet Propulsion Laboratory. Retrieved 8 June 2020.
  3. ^ a b c d e Perna, D.; Barucci, M. A.; Fulchignoni, M.; Popescu, M.; Belskaya, I.; Fornasier, S.; et al. (August 2018). "A spectroscopic survey of the small near-Earth asteroid population: Peculiar taxonomic distribution and phase reddening". Planetary and Space Science. 157: 82–95. arXiv: 1803.08953. Bibcode: 2018P&SS..157...82P. doi: 10.1016/j.pss.2018.03.008. ISSN  0032-0633. S2CID  119426280.
  4. ^ a b c d Masiero, Joseph R.; Nugent, C.; Mainzer, A. K.; Wright, E. L.; Bauer, J. M.; Cutri, R. M.; et al. (October 2017). "NEOWISE Reactivation Mission Year Three: Asteroid Diameters and Albedos". The Astronomical Journal. 154 (4): 10. arXiv: 1708.09504. Bibcode: 2017AJ....154..168M. doi: 10.3847/1538-3881/aa89ec. S2CID  45334910.
  5. ^ a b Warner, Brian D. (January 2017). "Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2016 July-September" (PDF). Minor Planet Bulletin. 44 (1): 22–36. Bibcode: 2017MPBu...44...22W. ISSN  1052-8091. PMC  7243971. PMID  32455389.
  6. ^ a b "LCDB Data for (163348) 2002 NN4". Asteroid Lightcurve Database (LCDB). Retrieved 8 June 2020.
  7. ^ Plait, Phil (4 June 2020). "No, we're not in any danger from an asteroid passing Earth on Saturday night". Bad Astronomy. Retrieved 9 June 2020. (Neowise Table)

External links

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