483P/PanSTARRS

For other comets of the same name, see List of Pan-STARRS discoveries.

483P/PanSTARRS (provisional designation P/2016 J1) is a pair of active main-belt asteroids that split apart from each other in early 2010. The brightest and largest component of the pair, P/2016 J1-A, was discovered first by the Pan-STARRS 1 survey at Haleakalā Observatory on 5 May 2016. Follow-up observations by the Canada-France-Hawaii Telescope at Mauna Kea Observatory discovered the second component, P/2016 J1-B, on 6 May 2016.^[9] Both asteroids are smaller than 1 kilometre (0.62 mi) in diameter, with P/2016 J1-A being roughly 0.6 km (0.37 mi) in diameter and P/2016 J1-B being roughly 0.3 km (0.19 mi) in diameter.^[7]: 18 The two components recurrently exhibit cometary activity as they approach the Sun near perihelion, suggesting that their activity is driven by sublimation of volatile compounds such as water.^[7]

483P/PanSTARRS

Canada-France-Hawaii Telescope image of split asteroid pair P/2016 J1 on 6 May 2016, showing comet-like tails on both components
Discovery[1]
Discovered by	Pan-STARRS 1
Discovery site	Haleakalā Observatory
Discovery date	5 May 2016
Designations
Alternative designations	P/2016 J1 (PanSTARRS)
Orbital characteristics (fragment A)[2]
Epoch	21 June 2016 (JD 2457560.5)
Observation arc	153 days (A)[2] 140 days (B)[3]
Earliest precovery date	4 March 2016[2]
Orbit type	main-belt (outer)[4] · Encke-type[2][3] · periodic[5][6]
Aphelion	3.896 AU
Perihelion	2.448 AU
Semi-major axis	3.172 AU
Eccentricity	0.2283
Orbital period	5.65 yr (2,064 days)
Inclination	14.330°
Longitude of ascending node	199.856°
Argument of periapsis	46.585°
Last perihelion	24 June 2016[2]
TJupiter	3.113
Earth MOID	1.461 AU
Jupiter MOID	1.227 AU
Physical characteristics
Mean diameter	<0.62+0.18 −0.10 km (A)[7]: 18  <0.34+0.12 −0.06 m (B)[7]: 18
Geometric albedo	0.04 (assumed)[4]
Spectral type	C/G[8] B–V = 0.74±0.04 (A)[8] B–V = 0.74±0.12 (B)[8] V–R = 0.36±0.04 (A)[8] V–R = 0.39±0.12 (B)[8]
Comet total magnitude (M1)	16.4±0.4 (A)[2] 17.3±0.8 (B)[3]
Comet nuclear magnitude (M2)	>19.95+0.18 −0.16 (A)[7]: 18  >21.26+0.23 −0.26 (B)[7]: 18

Orbit

Asteroid family

In 2018, an orbit analysis by Hsieh et al. found that both components of P/2016 J1 are related to the Theobalda asteroid family of C-, F-, and X-type asteroids. The Theobalda family likely originated as fragments from an impact event that shattered a 78 ± 9 km (48 ± 6 mi)-diameter parent body 6.9±2.3 million years ago.^[10]: 10 Another ice-sublimating active asteroid, 427P/ATLAS (P/2017 S5), was also identified to be part the Theobalda family, suggesting that some members of this family were able to retain subsurface water ice since the collision that formed them.^[11]: 7

See also

• Asteroid pair
  • (458271) 2010 UM₂₆ and (458271) 2010 RN₂₂₁ – a pair of main-belt asteroids thought to have recently dissociated from a binary system
• Active asteroid
  • (300163) 2006 VW139 – A widely-separated binary main-belt comet
  • P/2013 R3 (Catalina–PanSTARRS) – an active asteroid that completely disintegrated due to rotational breakup
  • 331P/Gibbs – another active asteroid disintegrating and fragmenting by rotational breakup