(523676) 2013 UL10 (prov. designation: 2013 UL10) is a reddish centaur with cometary activity orbiting the Sun between Jupiter and Uranus. It was discovered on 18 August 2010, by a team of astronomers with the Pan-STARRS survey at the Haleakalā Observatory, Hawaii.[1] It is the first centaur known to have both comet-like activity and red surface colors. It is also one of the smallest centaurs, with a nucleus of no more than 10 kilometers (6.2 miles) in diameter.[5] As of 2021, it has not been named.[1]

(523676) 2013 UL10
Discovery[1]
Discovered byPan-STARRS 1
Discovery siteHaleakalā Obs.
Discovery date18 August 2010
Designations
(523676) 2013 UL10
2013 UL10
centaur[2][3][4]
Orbital characteristics[2]
Epoch 1 July 2021 (JD 2459396.5)
Uncertainty parameter 1[2] · 0[1]
Observation arc7.56 yr (2,761 d)
Aphelion13.658 AU
Perihelion6.1724 AU
9.9153 AU
Eccentricity0.3775
31.22 yr (11,404 d)
81.728°
0° 1m 53.76s / day
Inclination19.164°
233.98°
4 June 2014[a]
186.17°
TJupiter2.94
Physical characteristics
Mean diameter
n.a.[6]
0.12 (nucleus)
12.8[1][2]

Orbit and classification edit

This object belongs to the centaurs, a dynamically unstable population of small Solar System bodies with chaotic orbits between the classical asteroids and the trans-Neptunian objects. Centaurs are considered to be objects with short lifetimes of approximately one million years, transitioning from the inactive population of Kuiper belt objects to the active group of Jupiter-family comets.[5] 2013 UL10 orbits the Sun at a distance of 6.2–13.7 AU once every 31 years and 3 months (11,404 days; semi-major axis of 9.92 AU). Its orbit has a high eccentricity of 0.38 and an inclination of 19° with respect to the ecliptic.[2] It has a Tisserand's parameter with respect to Jupiter (TJ) of 2.94, near the threshold of 3, typically used to distinguish asteroids from Jupiter-family comets. On 4 June 2014, the object came to perihelion at 6.2 AU and has since been moving away from the Sun.[a] As of 2021 the object is at 10.7 AU,[8] The body's observation arc begins with its official discovery observation at Haleakalā Observatory in August 2010.[1]

Numbering and naming edit

This minor planet was numbered by the Minor Planet Center on 25 September 2018, receiving the number (523676) in the minor planet catalog (M.P.C. 111778).[9] As of 2021, it has not been named.[1] According to the established naming conventions, it will be named after one of the many centaurs from Greek mythology, which are creatures with the upper body of a human and the lower body and legs of a horse.[10]

Physical characteristics edit

 
2013 UL10 has color index values similar to those of 1998 BU48.

As with other populations, the centaurs show a bimodal distribution of colors: red and blue-grey. Cometary-like activity is well known among the grey centaurs, prominently represented by 2060 Chiron, which is also the namesake of the Chiron-type comets. However, outgassing activity of red centaurs (e.g. 5145 Pholus) has not been observed. 2013 UL10 is the first of the group of red centaurs to display clear evidence of cometary activity.[5]

In October 2014, 2013 UL10 was observed by astronomers using the Large Monolithic Imager of the 4.3-meter Discovery Channel Telescope in Arizona. An overall reddish color was determined with B–V, V–R and B–R color indices of 0.97±0.02, 0.67±0.02 and 1.64±0.03, respectively. It was the intrinsically faintest object observed for this study, with an absolute magnitude 13.46.[6][7]

In December 2015, observations with the Galileo National Telescope on the Canary Islands revealed that 2013 UL10 exhibits comet-like activity. Apart from the object's dust coma, the astronomers also deduced a diameter of no more than 10 kilometers (6.2 miles) for this centaur's nucleus, assuming an albedo of 0.12. Further photometric observations gave a dust production rate of 10 kg/s near the object's perihelion at 6.2 AU.[5]

The Collaborative Asteroid Lightcurve Link an estimates a diameter of kilometers 15.3 based on a albedo of 0.057 (carbonaceous) and on an absolute magnitude of 12.8. As of 2021, no rotational lightcurve of 2013 UL10 has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown.[2]

See also edit

Notes edit

  1. ^ a b JPL Horizons Observer Location: @sun (Perihelion occurs when deldot changes from negative to positive.)

References edit

  1. ^ a b c d e f g "523676 (2013 UL10)". Minor Planet Center. Retrieved 28 July 2021.
  2. ^ a b c d e f "JPL Small-Body Database Browser: 523676 (2013 UL10)" (2018-03-10 last obs.). Jet Propulsion Laboratory. Retrieved 28 July 2021.
  3. ^ "Orbit Fit and Astrometric record for 523676". Southwest Research Institute. Retrieved 28 July 2021.The Deep Ecliptic Survey Object Classifications
  4. ^ a b Johnston, Wm. Robert (18 August 2020). "List of Known Trans-Neptunian Objects". Johnston's Archive. Retrieved 28 July 2021.
  5. ^ a b c d e Mazzotta Epifani, E.; Dotto, E.; Ieva, S.; Perna, D.; Palumbo, P.; Micheli, M.; et al. (December 2018). "523676 (2013 UL10): the first active red centaur" (PDF). Astronomy and Astrophysics. 620: A93. Bibcode:2018A&A...620A..93M. doi:10.1051/0004-6361/201731224. ISSN 0004-6361. S2CID 126274614.
  6. ^ a b c d e "LCDB Data for (523676)". Asteroid Lightcurve Database (LCDB). Retrieved 28 July 2021.
  7. ^ a b c d Tegler, S. C.; Romanishin, W.; Consolmagno, G. J.; J., S. (December 2016). "Two Color Populations of Kuiper Belt and Centaur Objects and the Smaller Orbital Inclinations of Red Centaur Objects". The Astronomical Journal. 152 (6): 210. Bibcode:2016AJ....152..210T. doi:10.3847/0004-6256/152/6/210. ISSN 0004-6256.
  8. ^ "Asteroid (523676) 2013 UL10 – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 28 July 2021.
  9. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 28 July 2021.
  10. ^ "Naming of Astronomical Objects – Minor planets". IAU – International Astronomical Union. Retrieved 27 July 2021.

External links edit