(436724) 2011 UW158

Last updated

(436724) 2011 UW158
2011UW158.jul14.p05us.p27Hz(1).gif
Animation of Arecibo radar images of 2011 UW158
Discovery [1]
Discovered by Pan-STARRS 1
Discovery site Haleakala Obs.
Discovery date25 October 2011
Designations
(436724) 2011 UW158
2011 UW158
Apollo  · NEO  · PHA [1] [2]
Orbital characteristics [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 5.48 yr (2,003 days)
Aphelion 2.2301 AU
Perihelion 1.0109 AU
1.6205 AU
Eccentricity 0.3762
2.06 yr (753 days)
12.072°
0° 28m 40.08s / day
Inclination 4.5717°
286.00°
8.7537°
Earth  MOID 0.0020 AU ·0.8 LD
Physical characteristics
Dimensions0.22±0.04 km [3]
0.3 × 0.6 km [4]
0.311 km (calculated) [5]
0.61069±0.00002 h [6] [lower-alpha 1]
0.61070±0.00003 h [3]
0.61073 h [5]
0.610752±0.000001 h [7]
0.20 (assumed) [5]
0.39±0.09 [3]
S [5]
19.45±0.27 [8]  ·19.9 [1] [5]  ·19.93±0.11 [3]

    (436724) 2011 UW158, provisionally known as 2011 UW158, is a stony, walnut-shaped asteroid and fast rotator, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 300 meters in diameter. It was discovered on 25 October 2011, by Pan-STARRS at Haleakala Observatory on the island of Maui, Hawaii, in the United States. [2]

    Contents

    Orbital description

    2011 UW158 orbits the Sun at a distance of 1.0–2.2  AU once every 2 years and 1 month (753 days). Its orbit has an eccentricity of 0.38 and an inclination of 5° with respect to the ecliptic. [1] Its observation arc begins with its official discovery observation by Pan-STARRS, as no precoveries were taken, and no prior identifications were made. [2]

    Close approach

    The asteroid has an Earth minimum orbit intersection distance of 0.0020 AU (300,000 km), which corresponds to 0.8 lunar distances (LD). On 19 July 2015, it passed about 2.5 million kilometers from Earth (6.5 LD), [1] attracting the interest of astronomers. [1] The asteroid was listed as level 1 in the Torino Scale on 4 November 2011, 9 days after its discovery, but was removed two weeks later. [9] [10]

    2011 UW158 July2015 flyby-orbits.png
    2011 UW158 July2015 flyby-sky trajectory.png
    Left: Inner solar system orbits; right: Motion of 2011 UW158 across sky, 6 hour motion

    Physical characteristics

    Spectral type

    2011 UW158 is an assumed stony S-type asteroid, the most common type among the populations of near-Earth and inner main-belt asteroids. [5]

    Diameter and albedo

    Bruce Gary at Hereford Arizona Observatory ( G95 ) estimated a mean-diameter of 220 meters with a high albedo of 0.39, [3] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroid of 0.20 and calculates a mean-diameter of 311 meters based on an absolute magnitude of 19.9. [5]

    Fast rotator

    In July and August 2015, rotational lightcurves of this asteroid were obtained from photometric observations by Bruce Gary at Hereford Arizona Observatory and by Brian Warner at the CS3–Palmer Divide Station in California ( U82 ). Lightcurve analysis gave a rotation period of 0.6107 hours (36.6 minutes) with a brightness variation between 0.52 and 2.05 magnitude ( U=3/3/3 ). [3] [6] [lower-alpha 1] This makes 2011 UW158 one of the Top 200 fast rotator, suggesting it is a large boulder rather than a rubble pile. [6] [11]

    Shape

    Radar observations by the Arecibo Observatory on 14 July 2015, revealed that the asteroid's shape looks like an unshelled walnut with a diameter of 300 by 600 metres. The radiometric observations also agreed with the previously obtained photometric ones and gave a period of 37 minutes. [4] [11]

    Media attention

    It also attracted the media and even firms such as Planetary Resources [12] for its alleged content of platinum worth as high as 5 trillion U.S. dollars. [13] [14] [15] Commenters at StackExchange have denied these estimations as being "orders of magnitude too high", [16] and radar observations have shown that the object contains no more metal than an average rocky asteroid. [17] [18]

    Notes

    1. 1 2 Lightcurve plot of 2011 UW158 by Brian Warner at the CS3–Palmer Divide Station in July 2015: rotation period of 0.61069±0.00002 hours with an amplitude of 0.65 magnitude

    Related Research Articles

    5264 Telephus is a large Jupiter trojan from the Greek camp, approximately 70 kilometers in diameter. It was discovered on 17 May 1991, by American astronomer couple Carolyn and Eugene Shoemaker at the Palomar Observatory in California, and later named after King Telephus from Greek mythology. The dark and possibly elongated D-type asteroid belongs to the 50 largest Jupiter trojans and has a rotation period of 9.5 hours.

    (12538) 1998 OH is a stony asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 1.8 kilometers in diameter. It was discovered on 19 July 1998, by astronomers of the Near-Earth Asteroid Tracking program at the Haleakala Observatory in Hawaii, United States. In 2019, the asteroid came within about 73 lunar distances of Earth.

    3709 Polypoites is a large Jupiter trojan from the Greek camp, approximately 85 kilometers in diameter. The Trojan asteroid was discovered on 14 October 1985, by American astronomer Carolyn Shoemaker at the Palomar Observatory in California, United States, and named after Polypoites from Greek mythology. The dark D-type asteroid belongs to the 50 largest Jupiter trojans. It has a rotation period of 10 hours and possibly a spherical shape.

    4063 Euforbo is a large Jupiter trojan from the Greek camp, approximately 100 kilometers in diameter. It was discovered on 1 February 1989, by Italian astronomers at the San Vittore Observatory near Bologna, Italy. The dark D-type asteroid is one of the 25 largest Jupiter trojans and has a rotation period of 8.8 hours. It was named after Euphorbus (Euforbo) from Greek mythology.

    <span class="mw-page-title-main">3122 Florence</span> Near-Earth asteroid with 2 moons

    3122 Florence is a stony trinary asteroid of the Amor group. It is classified as a near-Earth object and potentially hazardous asteroid. It measures approximately 5 kilometers in diameter. It orbits the Sun at a distance of 1.0–2.5 AU once every 2 years and 4 months ; the orbit has an eccentricity of 0.42 and an inclination of 22° with respect to the ecliptic. Florence has two moons.

    8013 Gordonmoore, provisional designation 1990 KA, is an eccentric, stony asteroid and near-Earth object of the Apollo group, approximately 1–2 kilometers in diameter.

    3793 Leonteus is a large Jupiter trojan from the Greek camp, approximately 90 kilometers in diameter. It was discovered on 11 October 1985, by American astronomer couple Carolyn and Eugene Shoemaker at the Palomar Observatory in California, United States. The D-type Jovian asteroid belongs to the 30 largest Jupiter trojans and has a rotation period of 5.6 hours. It was named after the hero Leonteus from Greek mythology.

    2895 Memnon is a dark Jupiter trojan from the Trojan camp, approximately 56 kilometers in diameter. It was discovered on 10 January 1981, by American astronomer Norman Thomas at Lowell's Anderson Mesa Station near Flagstaff, Arizona, in the United States. The assumed C-type asteroid has a rotation period of 7.5 hours and belongs to the 80 largest Jupiter trojans. It was named after King Memnon from Greek mythology.

    4068 Menestheus is a dark Jupiter trojan from the Greek camp, approximately 67 kilometers in diameter. It was discovered on 19 September 1973, by Dutch astronomers Ingrid and Cornelis van Houten at Leiden, on photographic plates taken by Tom Gehrels at the Palomar Observatory in California, United States. The D-type asteroid belongs to the 60 largest Jupiter trojans and has a rotation period of 14.4 hours. It was named after the Athen leader Menestheus from Greek mythology.

    1727 Mette, provisional designation 1965 BA, is a binary Hungaria asteroid and Mars-crosser from the inner regions of the asteroid belt, approximately 9 kilometers in diameter.

    5284 Orsilocus is a Jupiter trojan from the Greek camp, approximately 50 kilometers in diameter. It was discovered on 1 February 1989, by American astronomers Carolyn and Eugene Shoemaker at the Palomar Observatory in California. The D-type asteroid belongs the 100 largest Jupiter trojans and has a rotation period of 10.3 hours. It was named after the hero Orsilochus (Orsilocus) from Greek mythology.

    4867 Polites is a Jupiter trojan from the Trojan camp, approximately 60 kilometers in diameter. It was discovered on 27 September 1989, by American astronomer Carolyn Shoemaker at the Palomar Observatory in California. The dark Jovian asteroid belongs to the 80 largest Jupiter trojans and has a rotation period of 11.2 hours. It was named after the Trojan prince Polites from Greek mythology.

    2074 Shoemaker, provisional designation 1974 UA, is a stony Hungaria asteroid, Mars-crosser and suspected synchronous binary system from the innermost regions of the asteroid belt, approximately 4 kilometers in diameter. It was discovered on 17 October 1974, by astronomer Eleanor Helin at the Palomar Observatory. She named it after American astronomer Eugene Shoemaker.

    2047 Smetana, provisional designation 1971 UA1, is a bright Hungaria asteroid and synchronous binary system from the innermost regions of the asteroid belt, approximately 3.5 kilometers in diameter. It was discovered on 26 October 1971, by Czech astronomer Luboš Kohoutek at Bergedorf Observatory in Hamburg, Germany. The asteroid was named after Czech composer Bedřich Smetana. Its sub-kilometer sized minor-planet moon was discovered in 2012.

    <span class="mw-page-title-main">4715 Medesicaste</span>

    4715 Medesicaste (prov. designation: 1989 TS1) is a dark Jupiter trojan from the Trojan camp, approximately 64 kilometers (40 miles) in diameter. It was discovered on 9 October 1989, by Japanese astronomer Yoshiaki Oshima at the Gekko Observatory east of Shizuoka, Japan. The assumed C-type asteroid belongs to the 70 largest Jupiter trojans. It is possibly elongated in shape and has a rotation period of 8.8 hours. It was named from Greek mythology after Medesicaste, an illegitimate daughter of Trojan King Priam.

    2015 HM10 is an irregular shaped asteroid and sub-kilometer near-Earth object that passed near the Earth on 7 July 2015, at a distance of 442,000 kilometers or 1.15 lunar distances.

    <span class="nowrap">(163899) 2003 SD<sub>220</sub></span>

    (163899) 2003 SD220 is a sub-kilometer asteroid and tumbling slow rotator, classified as near-Earth object and potentially hazardous asteroid of the Aten group, which orbit the Sun between Venus and Earth. Its orbital period of 0.75 years means that it orbits the Sun about 4 times for every 3 of the Earth. It was discovered on 29 September 2003, by astronomers of the Lowell Observatory Near-Earth-Object Search at Anderson Mesa Station near Flagstaff, Arizona.

    15440 Eioneus, provisional designation: 1998 WX4, is a dark Jupiter trojan from the Greek camp, approximately 66 kilometers (41 miles) in diameter. It was discovered on 19 November 1998, by astronomers with the Catalina Sky Survey at the Catalina Station near Tucson, Arizona, in the United States. The assumed C-type asteroid belongs to the 60 largest Jupiter trojans. It has a rotation period of 21.43 hours and possibly a spherical shape. It was named from Greek mythology after Eioneus who was killed by Hector.

    (15502) 1999 NV27 (provisional designation 1999 NV27) is a Jupiter trojan from the Trojan camp, approximately 53 kilometers (33 miles) in diameter. It was discovered on 14 July 1999, by astronomers with the Lincoln Near-Earth Asteroid Research at the Lincoln Lab's ETS near Socorro, New Mexico, in the United States. The dark Jovian asteroid has a rotation period of 15.1 hours and belongs to the 90 largest Jupiter trojans. It has not been named since its numbering in June 2000.

    (15977) 1998 MA11 (provisional designation 1998 MA11) is a Jupiter trojan from the Trojan camp, approximately 45 kilometers (28 miles) in diameter. It was discovered on 19 June 1998, by astronomers with the Lincoln Near-Earth Asteroid Research at the Lincoln Lab's ETS near Socorro, New Mexico, in the United States. The suspected tumbler is also a slow rotator with a period of 250 hours. It has not been named since its numbering in July 2000.

    References

    1. 1 2 3 4 5 6 7 "JPL Small-Body Database Browser: 436724 (2011 UW158)" (2017-04-19 last obs.). Jet Propulsion Laboratory . Retrieved 2 June 2017.
    2. 1 2 3 "436724 (2011 UW158)". Minor Planet Center. Retrieved 28 March 2017.
    3. 1 2 3 4 5 6 Gary, Bruce L. (January 2016). "Unusual Properties for the NEA (436724) 2011 UW158". The Minor Planet Bulletin. 43 (1): 33–38. Bibcode:2016MPBu...43...33G. ISSN   1052-8091 . Retrieved 28 March 2017.
    4. 1 2 "Solar System Studies at Arecibo Observatory". Arecibo Observatory. Retrieved 23 July 2015.
    5. 1 2 3 4 5 6 7 "LCDB Data for (436724)". Asteroid Lightcurve Database (LCDB). Retrieved 28 March 2017.
    6. 1 2 3 Warner, Brian D. (January 2016). "Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2015 June-September". The Minor Planet Bulletin. 43 (1): 66–79. Bibcode:2016MPBu...43...66W. ISSN   1052-8091. PMC   7244002 . PMID   32455369 . Retrieved 28 March 2017.
    7. ↑ Carbognani, Albino; Gary, Bruce L.; Oey, Julian; Baj, Giorgio; Bacci, Paolo (January 2016). "Pole and Shape for the NEA (436724) 2011 UW158". The Minor Planet Bulletin. 43 (1): 38–41. Bibcode:2016MPBu...43...38C. ISSN   1052-8091 . Retrieved 28 March 2017.
    8. ↑ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv: 1506.00762 . Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. S2CID   53493339 . Retrieved 28 March 2017.
    9. ↑ "2011 UW158 Impact Risk". Near Earth Object Program. NASA. Archived from the original on 6 November 2011.
    10. ↑ "NEOs Removed from Impact Risks Tables". Near Earth Object Program. NASA. Archived from the original on 2 June 2002. Retrieved 28 March 2017.
    11. 1 2 "First detailed images of rare asteroid to pass close by Earth on 19 July". Astronomy Now. 19 July 2015. Retrieved 28 March 2017.
    12. ↑ "Mining Firm Aiming For Platinum-Loaded Asteroid" . Retrieved 23 July 2015.[ dead link ]
    13. ↑ "UW-158: Watch live as asteroid worth £ 3 TRILLION passes close to Earth" . Retrieved 23 July 2015.
    14. ↑ "What you can expect to see as a £3 trillion asteroid passes Earth tonight" . Retrieved 23 July 2015.
    15. ↑ "$5 Trillion Dollar Asteroid Makes Close Approach to Earth" . Retrieved 23 July 2015.
    16. ↑ "How is it known that asteroid 2011 UW158 has so much platinum?" . Retrieved 23 July 2015.
    17. ↑ "5th IAA Planetary Defense Conference" (PDF). Archived from the original (PDF) on 19 August 2019. Retrieved 3 June 2017.
    18. ↑ "Ground-based radar observations of human space flight accessible targets" . Retrieved 3 June 2017.
    This page is based on this Wikipedia article
    Text is available under the CC BY-SA 4.0 license; additional terms may apply.
    Images, videos and audio are available under their respective licenses.