2015 FG415

2015 FG₄₁₅ is a trans-Neptunian object from the scattered disc, located in the outermost region of the Solar System. It was discovered on 17 March 2015, by American astronomer Scott Sheppard at the Mauna Kea Observatories, Hawaii,^[1] and received the provisional designation 2015 FG₄₁₅. As of 2021^[update], it is the 9th-most-distant object from the Sun at 87.2 AU and measures approximately 280 kilometers (170 miles) in diameter.^[5]

2015 FG₄₁₅

Discovery[1][2][3]
Discovered by	S. S. Sheppard
Discovery site	Mauna Kea Obs.
Discovery date	17 March 2015
Designations
MPC designation	2015 FG415
Minor planet category	TNO[4] · SDO[5] near-scattered (DES)[6]
Orbital characteristics[4]
Epoch 1 July 2021 (JD 2459396.5)
Uncertainty parameter 6[1] · 7[4]
Observation arc	3.89 yr (1,419 d)
Aphelion	91.925 AU
Perihelion	36.009 AU
Semi-major axis	63.967 AU
Eccentricity	0.4371
Orbital period (sidereal)	511.61 yr (186,866 d)
Mean anomaly	227.77°
Mean motion	0° 0m 6.84s / day
Inclination	4.7230°
Longitude of ascending node	6.7523°
Argument of perihelion	314.55°
Physical characteristics
Mean diameter	280 km (est.)[5][7]
Absolute magnitude (H)	6.0[1][4]

Orbit and classification

2015 FG₄₁₅ orbits the Sun at a distance of 36.0–91.9 AU once every 511 years and 7 months (186,866 days; semi-major axis of 63.97 AU). Its orbit has an eccentricity of 0.44 and an inclination of 5° with respect to the ecliptic.^[4]

It is classified as a scattered disc object,^[5] or "near-scattered" in the classification of the Deep Ecliptic Survey,^[6] that still interacts gravitationally with Neptune (30.1 AU) due to its relatively low perihelion of 36.0 AU, contrary to the extended-scattered/detached objects and sednoids which never approach Neptune as close.

Most distant objects from the Sun

2015 FG₄₁₅ will come to perihelion in 2209,^[4] moving towards the Sun, currently located at a distance of 87.2 AU,^[8] which makes it the 9th-most-distant known minor planet in the Solar System,^[9] after 2018 AG37, 2018 VG18, 2020 FY30, 2020 FA31, Eris, 2015 TH367, 2014 UZ224, and Gonggong, (also see List of Solar System objects most distant from the Sun § Known distant objects).

Physical characteristics

Based on a generic magnitude-to-diameter conversion, 2015 FG₄₁₅ measures approximately 280 kilometers (170 miles) in diameter, for an assumed albedo of 0.9 with an absolute magnitude of 6.0.^[5][7] Mike Brown considers this object to be a weak dwarf planet candidate ("possibly") estimating a mean-diameter of 277 km (170 mi).^[10] As of 2021^[update], no rotational lightcurve for this object has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown.^[4]