(505657) 2014 SR339, provisional designation 2014 SR339, is a dark and elongated asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 970 meters (3,200 feet) in diameter. It was discovered on 30 September 2014, by NASA's Wide-field Infrared Survey Explorer telescope (WISE) in Earth's orbit.[1] Closely observed at Goldstone and Arecibo in February 2018, it has a rotation period of 8.7 hours.[5]
 Radar images of 2014 SR339 taken by the Arecibo Observatory on 9 February 2018 | |
| Discovery[1] | |
|---|---|
| Discovered by | WISE |
| Discovery site | Earth orbit |
| Discovery date | 30 September 2014 |
| Designations | |
| (505657) 2014 SR339 | |
| 2014 SR339 | |
| Apollo · NEO · PHA[1][2] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 3.41 yr (1,245 d) |
| Aphelion | 1.6948 AU |
| Perihelion | 0.9046 AU |
| 1.2997 AU | |
| Eccentricity | 0.3040 |
| 1.48 yr (541 d) | |
| 60.524° | |
| 0° 39m 54.72s / day | |
| Inclination | 29.790° |
| 138.78° | |
| 299.60° | |
| Earth MOID | 0.0354 AU (13.8 LD) |
| Physical characteristics | |
| Dimensions | (>1.5 km × ? km)[3] |
| 0.971±0.367 km[4] | |
| 8–9 h[5] 8.729 h[3][a] | |
| 0.068±0.074[4] | |
| C(assumed on albeo) | |
| 18.6[2] | |
Orbit and classification
edit2014 SR339 is a member of the Apollo asteroids, which cross the orbit of Earth. Apollo's are the largest group of near-Earth objects with nearly 10 thousand known objects. It orbits the Sun at a distance of 0.90–1.70 AU once every 18 months (541 days; semi-major axis of 1.30 AU). Its orbit has an eccentricity of 0.30 and an inclination of 30° with respect to the ecliptic.[2] With an aphelion of 1.70 AU, it is also a Mars-crosser, as it crosses the orbit of the Red Planet at 1.666 AU. The body's observation arc begins with its official discovery observation by WISE in September 2014.[1]
Close approaches
editAs a potentially hazardous asteroid, 2014 SR339 has a minimum orbital intersection distance (MOID) with Earth of less than 0.05 AU and a diameter of greater than 150 meters. The Earth-MOID is currently 0.0354 AU (5,300,000 km), which translates into 13.8 lunar distances (LD).[2]
2018 flyby
editOn 7 February 2018 it passed 0.054 AU (21 LD) from the Earth when its apparent magnitude brightened to 14.[3] Goldstone observed it until the following day.[6] While this was an 8.1-million kilometer flyby, the next close flyby of 6.3 million km will occur on 5 February 2058, and another 7.6 million km on 8 February 2095. It will also have a 3.2 million km flyby of Mars on 26 September 2048.[7]
Physical characteristics
editThe asteroid's spectral type is unknown. Due to its unusually low albedo (see below) it is likely a carbonaceous C-type asteroid.[2]
Rotation period
editOn 9 February, radiometric observations by the Arecibo Observatory revealed that the asteroid has an elongated, lumpy shape.[3] The radar images also gave it a rotational period between 8 and 9 hours.[5] A refined period of 8.7 hour agrees with (photometric) lightcurve observations by American photometrist Brian Warner at the Center for Solar System Studies (U82) during 9–11 February 2018, who obtained a period of 8.729 hours with a high brightness amplitude of 0.93 magnitude, which also indicates a non-spheroidal shape (U=3-).[3][a]
Diameter and albedo
editAccording to the survey carried out by the NEOWISE mission of NASA's WISE telescope, 2014 SR339 measures 0.971 kilometers in diameter and its surface has an albedo of 0.068.[4] During its close approach in February 2018, radiometric observations by Arecibo Observatory determined that the object is at least 1.5 kilometers (0.93 miles) wide.[3] Data from the Arecibo Telescope released in 2022 showed an unusually high radar albedo, possibly indicating rich metal content.[8]
Numbering and naming
editThis minor planet was numbered by the Minor Planet Center on 4 November 2017 (M.P.C. 107069).[9] As of 2018, it has not been named.[1]
Gallery
edit-
Daily motion of asteroid across sky -
View of flyby above the earth and moon
Notes
edit- ^ a b lightcurve plot of (505657) 2014 SR339: rotation period 8.729±0.002 hours with a brightness amplitude of 0.93 mag. Quality code of 3-. Summary figures at the Center for Solar System Studies (CS3)
References
edit- ^ a b c d e "505657 (2014 SR339)". Minor Planet Center. Retrieved 5 March 2018.
- ^ a b c d e f "JPL Small-Body Database Browser: 505657 (2014 SR339)" (2018-02-26 last obs.). Jet Propulsion Laboratory. Retrieved 5 March 2018.
- ^ a b c d e f "Near-Earth asteroid (505657) 2014 SR339". Arecibo Observatory – NASA/JPL. 14 February 2018. Retrieved 5 March 2018.
- ^ a b c Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. S2CID 9341381.
- ^ a b c "Recent radar images of (505657) 2014 SR339". Twitter. Retrieved 5 March 2018.
Recent radar images of near-Earth asteroid (505657) 2014 SR339 from @NAICobservatory show a lumpy, elongated body at least 1.5 km long and rotating once every 8 to 9 hours!
- ^ "Goldstone Radar Observations Planning: Asteroids 2002 AJ129, 2014 SR339, 2015 BN509, and 2018 CB". Lance Benner – NASA/JPL. Retrieved 5 March 2018.
- ^ "Asteroid 505657 2014 SR339". asteroidsnear.com. Retrieved 5 March 2018.
- ^ Colin Stuart (1 November 2022), "ARECIBO LEGACY: NEW DATA ON NEAR-EARTH ASTEROIDS", Sky & Telescope
- ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 5 March 2018.
External links
edit
- List of the Potentially Hazardous Asteroids (PHAs), Minor Planet Center
- List Of Apollo Minor Planets (by designation), Minor Planet
- Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
- (505657) 2014 SR339 at NeoDyS-2, Near Earth Objects—Dynamic Site
- (505657) 2014 SR339 at ESA–space situational awareness
- (505657) 2014 SR339 at the JPL Small-Body Database