Artist's impression of 38628 Huya
|Discovery and designation|
|Discovered by||Ignacio Ferrin|
|Discovery date||March 10, 2000|
|MPC designation||38628 Huya|
|Alternative names||2000 EB173|
|Minor planet category||TNO
|Epoch January 4, 2010 (JD 2455200.5)|
|Aphelion||50.363 AU (7534 Gm)|
|Perihelion||28.520 AU (4266 Gm)|
|Semi-major axis||39.442 AU (5900 Gm)|
|Orbital period||247.72 yr (90477 d)|
|Average orbital speed||4.63 km/s|
|Longitude of ascending node||169.40°|
|Argument of perihelion||68.169°|
|Sidereal rotation period||13.5 hr(?)|
|Geometric albedo||0.081 ± 0.011|
|Spectral type||B−V=0.95 ± 0.05
V−R=0.57 ± 0.09
|Apparent magnitude||19.3 (opposition)|
|Absolute magnitude (H)||5.14 ± 0.07
5.37 ± 0.04 
|Angular diameter||0.024″ (max)[note 1]|
38628 Huya is a trans-Neptunian object (TNO). It is a plutino, being in a 2:3 mean motion resonance with Neptune. With an old Spitzer size estimate of 532 ± 25 km, it was a possible dwarf planet (icy trans-Neptunian objects with a diameter above around 400 km are expected to be spherical) although the IAU has never classified it as such. Light-curve-amplitude analysis, which shows only small deviations, suggests that it is likely a spheroid with small albedo spots. Tancredi (2010) thinks that Huya is very probably a dwarf planet.
It was discovered in March 2000 by Ignacio Ferrin and announced on 24 October 2000. It was assigned the name Huya, after Juyá, the Wayuu rain god, in August 2003 by the International Astronomical Union (IAU).
A satellite reported on IAU Circular 9253 on 12 July 2012 was discovered by K. S. Noll, W. M. Grundy, H. Schlichting, R. Murray-Clay, and S. D. Benecchi from Hubble Space Telescope observations obtained 6 May 2012, confirmed in reexamination of Hubble Space Telescope imagery from 30 June-1 July 2012. It has an estimated diameter of 202 km and a separation of 1,800 km from primary.
At the time of its discovery, Huya was the biggest and brightest trans-Neptunian object found since Pluto. It was found using data collected by at the CIDA Observatory in Venezuela.
The Spitzer Space Telescope has estimated Huya to be about 530 km in diameter with a low albedo of around 0.05. The later termination based on a combination of Spitzer and Herschel measurements yielded a smaller size estimate of 438.7+26.5
Huya has a moderately red-sloped reflectance spectrum in the visible and near-infrared, suggesting a surface rich in organic material such as tholins. There is a broad absorption feature near 2 μm possibly belonging to water ice or some water-altered material. Additional absorption features may be present near 0.6–0.8 μm, which may be caused by aqueously altered anhydrous silicates.
Orbit and rotation
Huya is currently 28.7 AU from the Sun, and will come to perihelion (q=28.52 AU) in 2015. This means that this probable dwarf planet is currently inside the orbit of the planet Neptune. Like Pluto, this plutino spends part of its orbit closer to the Sun than Neptune, even though their orbits are controlled by Neptune. Huya will be closer to the Sun than Neptune until about July 2029. Simulations by the Deep Ecliptic Survey (DES) show that over the next 10 million years Huya can acquire a perihelion distance (qmin) as small as 27.28 AU. Plutinos (15875) 1996 TP66 and (120216) 2004 EW95 get even closer to the Sun.
- Huya Angular Size at May 2015 Opposition: 480km dia / (27.5543AU * 149 597 870km) * 206265 = 0.024″
- Buie, M. W. (22 April 2007). "Orbit Fit and Astrometric record for 38628". SwRI (Space Science Department). Retrieved 2008-07-17.
- "MPEC 2009-C70 :Distant Minor Planets (2009 FEB. 28.0 TT)". Minor Planet Center. 2009-02-10. Retrieved 2009-03-24.
- "38628 Huya (2000 EB173)". JPL Small-Body Database. Jet Propulsion Laboratory. SPK-ID: 2038628. Retrieved 2008-07-17.
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- Mommert, M.; et al. (2012). "TNOs are cool: A survey of the trans-Neptunian region V. Physical characterization of 18 Plutinos using Herschel-PACS observations". Astronomy & Astrophysics 541: A93. arXiv:1202.3657. Bibcode:2012A&A...541A..93M. doi:10.1051/0004-6361/201118562.
- "AstDys (38628) Huya Ephemerides". Department of Mathematics, University of Pisa, Italy. Retrieved 2009-03-22.
- Doressoundiram, A.; et al. (2007). "The Meudon Multicolor Survey (2MS) of Centaurs and Trans-Neptunian Objects: From Visible to Infrared Colors". The Astronomical Journal 134 (6): 2186. Bibcode:2007AJ....134.2186D. doi:10.1086/522783.
- Stansberry, J.; et al. (2007). "Physical Properties of Kuiper Belt and Centaur Objects: Constraints from Spitzer Space Telescope". In Barucci, M. A.; et al.. The Solar System Beyond Neptune. University of Arizona Press. pp. 161–179. arXiv:astro-ph/0702538. Bibcode:2008ssbn.book..161S. ISBN 978-0-8165-2755-7.
- Brown, M. E. (23 September 2011). "How many dwarf planets are there in the outer solar system? (updates daily)". California Institute of Technology. Retrieved 2011-09-23.
- Brown, M. E. "The Dwarf Planets". California Institute of Technology. Archived from the original on 29 January 2008. Retrieved 2008-01-20.
- Tancredi, G.; Favre, S. (2008). "Which are the dwarfs in the Solar System?". Icarus 195 (2): 851. Bibcode:2008Icar..195..851T. doi:10.1016/j.icarus.2007.12.020.
- Tancredi, G. (2009). "Physical and dynamical characteristics of icy "dwarf planets" (plutoids)". Proceedings of the International Astronomical Union 5: 173–15. Bibcode:2010IAUS..263..173T. doi:10.1017/S1743921310001717.
- Licandro, J.; Oliva, E.; Di Martino, M. (2001). "NICS-TNG infrared spectroscopy of trans-neptunian objects 2000 EB173 and 2000 WR106". Astronomy and Astrophysics 373 (3): L29–L32. arXiv:astro-ph/0105434. Bibcode:2001A&A...373L..29L. doi:10.1051/0004-6361:20010758.
- de Bergh, C.; et al. (2004). "Aqueous altered silicates at the surface of two Plutinos?". Astronomy and Astrophysics 416 (2): 791–798. Bibcode:2004A&A...416..791D. doi:10.1051/0004-6361:20031727.
- "38628 Huya (2000 EB173) ephemeris". JPL Small-Body Database. Jet Propulsion Laboratory. SPK-ID: 2038628. Retrieved 2009-03-23.
- Sheppard, S. S.; Lacedra, P.; Ortiz, J. L. (2008). "Photometric Lightcurves of Transneptunian Objects and Centaurs: Rotations, Shapes, and Densities". In Barucci, A. M. et al.. The Solar System Beyond Neptune. University of Arizona Press. pp. 129–142. ISBN 978-0-8165-2755-7.
- 37th DPS: Albedos, Diameters (and a Density) of Kuiper Belt and Centaur Objects
- Planet 10? Tiny 'Plutino' Almost Qualifies
- Discovery of a bright Trans-Neptunian Object (Yale)
- From the Rain Forest to Planet Huya