2015 HM10
{{Short description|Irregular shaped asteroid and sub-kilometer near-Earth object}}
{{DISPLAYTITLE:{{mp|2015 HM|10}}}}
{{use dmy dates|date=February 2018}}
{{Infobox planet
| minorplanet = yes
| name = {{mp|2015 HM|10}}
| background = #FFC2E0
| image =
| image_size =
| caption =
| discovery_site = Cerro Tololo Obs.
| discovered = 19 April 2015
| mpc_name = {{mp|2015 HM|10}}
| alt_names =
| pronounced =
| named_after =
| mp_category = NEO{{·}}Apollo
Amor
| epoch = 4 September 2017 (JD 2458000.5)
| uncertainty = 3
| observation_arc = 0.39 yr (141 days)
| aphelion = 4.0411 AU
| perihelion = 1.0085 AU
| semimajor = 2.5248 AU
| eccentricity = 0.6006
| period = 4.01 yr (1,465 days)
| mean_anomaly = 195.53°
| mean_motion = {{Deg2DMS|0.2457|sup=ms}} / day
| inclination = 1.4699°
| asc_node = 283.27°
| arg_peri = 353.48°
| moid = 0.0022 AU{{·}}0.9 LD
| dimensions = 0.057 km {{small|(calculated)}}
| rotation = {{val|0.3761|0.0001}} h
{{val|0.3763|0.0003}} h
| albedo = 0.20 {{small|(assumed)}}
| spectral_type = S {{small|(assumed)}}
}}
{{mp|2015 HM|10}} 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.
First observed on 19 April 2015, by astronomers of the Dark Energy Survey at Cerro Tololo Observatory in Chile, the asteroid measures approximately 60 meters in diameter and is classified as a member of the Apollo and Amor group, respectively. It is a fast rotator with a rotation period of 22.6 minutes.
Discovery
It was first observed on 19 April 2015, by astronomers of the Dark Energy Survey, using the Dark Energy Camera (DECam, {{small|W84}}) mounted on the Víctor M. Blanco Telescope located at Cerro Tololo Inter-American Observatory in Chile.
Orbit and classification
{{mp|2015 HM|10}} has been classified as a near-Earth object of the Apollo and Amor group, respectively.
It orbits the Sun at a distance of 1.0–4.0 AU once every 4.01 years (1,465 days). Its orbit has an eccentricity of 0.60 and an inclination of 1° with respect to the ecliptic. The body's observation arc begins with a precovery taken at Cerro Tololo, the night prior to its official first observation.
= Close encounters =
{{mp|2015 HM|10}} has an Earth minimum orbital intersection distance of {{convert |0.0022 |AU |km |abbr=on |lk=off |sigfig=3}} which corresponds to 0.9 lunar distances. On 7 July 2015, it passed Earth at {{convert |0.00295299 |AU |km |abbr=on |lk=off |sigfig=3}}, or 1.15 lunar distances. On the following day, it passed the Moon at {{convert |0.00276|AU |km |abbr=on |lk=off |sigfig=3}}. This was the asteroid's closest approach to Earth until at least 2419.
Physical characteristics
{{mp|2015 HM|10}} is an assumed to be a stony S-type asteroid.
= Rotation and shape =
During 2015, two rotational light curves of {{mp|2015 HM|10}} were obtained from photometric observations by Brian Warner at the Palmer Divide Station ({{small|U82}}) in California and by astronomers of the Mission Accessible Near-Earth Objects Survey (MANOS). Lightcurve analysis gave a rotation period of 0.3761 and 0.3763 hours (22.6 minutes) with a brightness amplitude of 1.50 and 1.29 magnitude ({{small|U=3/3-}}), indicative of a non-spheroidal shape. It is among the fastest rotators known to exists.
In July 2015, high-resolution images of {{mp|2015 HM|10}} were obtained from radiometric observations made with the Very Long Baseline Array, the Arecibo Observatory, and the 34 and 70-meter antennas at Goldstone. These observations confirmed the body's short rotation period and complex and irregular, and revealed, that it has a long-axis extent of 80–100 meters with an equatorial aspect ratio of about 2:1. Any significant non-principal axis rotation, commonly known as "tumbling" could be ruled out. The radar images also showed angular features up to approximately 30 meters across, with a cluster of radar-bright pixels following its rotation, and consistent with a high standing, 15 to 20 meters wide feature.
= Diameter and albedo =
The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a mean-diameter of 57.0 meters based on an absolute magnitude of 23.6. At its widest point, the object is 80 meters long.
Numbering and naming
As of 2017, this minor planet has neither been numbered nor named.
References
{{reflist|30em|refs=
|type = 2015-09-06 last obs.
|title = JPL Small-Body Database Browser: (2015 HM10)
|url = http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3717042
|publisher = Jet Propulsion Laboratory
|accessdate = 17 October 2017}}
|title = 2015 HM10
|work = Minor Planet Center
|url = http://www.minorplanetcenter.net/db_search/show_object?object_id=2015+HM10
|accessdate = 17 October 2017}}
|author1 = National Radio Astronomy Observatory
|title = Astronomy summer school radar observations shine new light on near-earth asteroid
|date = 14 July 2015
|url = http://phys.org/news/2015-07-astronomy-summer-school-radar-near-earth.html
|accessdate = 17 October 2017}}
|display-authors = 6
|first1 = Michael W. |last1 = Busch
|first2 = Lance A. M. |last2 = Benner
|first3 = Shantanu P. |last3 = Naidu
|first4 = Marina |last4 = Brozovic
|first5 = James E. |last5 = Richardson
|first6 = Edgard G. |last6 = Rivera-Valentin
|first7 = Patrick A. |last7 = Taylor
|first8 = H. Alyson |last8 = Ford
|first9 = Frank D. |last9 = Ghigo
|first10 = Jon D. |last10 = Giorgini
|first11 = Joseph S. |last11 = Jao
|first12 = Lawrence |last12 = Teitelbaum
|date = November 2015
|title = Asteroids With Tensile Strength: The Case of 2015 HM10
|journal = American Astronomical Society
|volume = 47 |pages = 402.05 |bibcode = 2015DPS....4740205B
}}
|title = LCDB Data for (2015 HM10)
|publisher = Asteroid Lightcurve Database (LCDB)
|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=0%7C2015+HM10
|accessdate = 17 October 2017}}
|first1 = Brian D. |last1 = Warner
|first2 = William H. |last2 = Ryan
|date = January 2016
|title = Lightcurve Analysis of NEA 2015 HM10
|journal = The Minor Planet Bulletin
|volume = 43
|issue = 1
|pages = 30–31
|pmid = 32455366
|pmc = 7244007
|issn = 1052-8091
|bibcode = 2016MPBu...43...30W
}}
|display-authors = 6
|first1 = A. |last1 = Thirouin
|first2 = N. |last2 = Moskovitz
|first3 = R. P. |last3 = Binzel
|first4 = E. |last4 = Christensen
|first5 = F. E. |last5 = DeMeo
|first6 = M. J. |last6 = Person
|first7 = D. |last7 = Polishook
|first8 = C. A. |last8 = Thomas
|first9 = D. |last9 = Trilling
|first10 = M. |last10 = Willman
|first11 = M. |last11 = Hinkle
|first12 = B. |last12 = Burt
|first13 = D. |last13 = Avner
|first14 = F. J. |last14 = Aceituno
|date = December 2016
|title = The Mission Accessible Near-Earth Objects Survey (MANOS): First Photometric Results
|journal = The Astronomical Journal
|volume = 152
|issue = 6
|page = 31
|bibcode = 2016AJ....152..163T
|doi = 10.3847/0004-6256/152/6/163
|arxiv = 1607.03517
|s2cid = 54090944 |doi-access = free }}
}}
External links
- [https://www.lpi.usra.edu/nuggets/2015/nugget_neo_nea_2015-08-14.pdf Close Pass of Near-Earth Asteroid 2015 HM10], Lunar and Planetary Institute
- [http://www.minorplanet.info/PHP/lcdbsummaryquery.php Asteroid Lightcurve Database (LCDB)], query form ([http://www.minorplanet.info/lightcurvedatabase.html info] {{Webarchive|url=https://web.archive.org/web/20171216050541/http://www.minorplanet.info/lightcurvedatabase.html |date=16 December 2017 }})
- {{NeoDys|2015HM10}}
- {{ESA-SSA|2015HM10}}
- {{JPL small body|id=3717042}}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:2015 HM10}}