2017 FO161

I refer to this message from Sam Deen published on the MPML list.

For what's worth due to the extreme orbit uncertainty (condition code 9), I tried to make a simulation.

JPL Small-Body Database Browser

[ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters ]

[ show orbit diagram ]

Orbital Elements at Epoch 2457968.5 (2017-Aug-03.0) TDB Reference: JPL 2 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .4495582354653219 0.16822 a 61.51516382073726 11.543 au q 33.86051531912641 3.9954 au i 54.05413287988313 0.053617 deg node 164.9909556914857 0.0017229 deg peri 145.4085682131792 32.795 deg M 251.4476070979913 79.839 deg tp 2511106.916053698100 (2163-Jan-28.41605370) 24126 TDB period 176226.6981677686 482.48 49602 135.8 d yr n .002042823271064628 0.00057499 deg/d Q 89.16981232234812 16.732 au

Orbit Determination Parameters    # obs. used (total)      14      data-arc span      354 days      first obs. used      2017-03-23      last obs. used      2018-03-12      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      9      norm. resid. RMS      .23801      source      ORB      producer      Otto Matic      solution date      2019-Feb-11 05:48:07   Additional Information  Earth MOID = 32.9588 au   Jupiter MOID = 29.3689 au   T_jup = 3.690

(2017 FO161)

Classification: TransNeptunian Object          SPK-ID: 3802117

Simulation
I generated 100 clones, trying to achieve the same distribution shown above.

Note: given the  uncertainty, the assumption of "normality" may not hold ...so this is another reason not to trust "blindly" the simulation results.

	Clones			Target
	mean	sd		mean	sd
q	33.3889976	3.99529506		33.86051532	3.9954
e	0.46907446	0.16820753		0.44955824	0.16822
i	54.04937496	0.05360707		54.05413288	0.053617
peri	141.63264456	32.79320364		145.40856821	32.795
node	164.99111511	0.00172288		164.99095569	0.0017229
tp	2508314.74330338	24125.06256158		2511106.9160537	24126

I configured the Mercury6 simulator (*) with an ejection distance equal to 100AU and integration algorithm Bulirsch-Stoer.

(*)
J.E.Chambers (1999) ``A Hybrid
      Symplectic Integrator that Permits Close Encounters between
      Massive Bodies''. Monthly Notices of the Royal Astronomical
      Society, vol 304, pp793-799.

Simulation Result

Do you think that a "still dormant" comet, constituted mainly by ice, can explain the fact that the object is brighter than expected?

Kind Regards,
Alessandro Odasso