RE: [find_orb] Planet MOIDs

Matson, Robert D. Aug 31, 2013

Looks like you're missing the oldest astrometry from 9/30/2011
through 1/28/2012. That might explain the discrepancy.

--Rob

-----Original Message-----
From: find_orb@yahoogroups.com on behalf of cbellh47
Sent: Sat 8/31/2013 8:11 AM
To: find_orb@yahoogroups.com
Subject: [find_orb] Planet MOIDs

Someone asked me what the planet MOIDs for comet C/2012 S1 (ISON) are. I ran Find_Orb with latest set of MPC observations. Find_Orb gives a good solution but surprisingly it gives an MOID for Mars

all perturbers on
Ma 0.1487
all perturbers off
Ma 0.1519

These values are much larger than Mars close approach nominal distance of about 0.0725 AU.

I'm stuck trying to resolve this.


Orbital elements:

C/2012 S1

Perihelion 2013 Nov 28.776713 TT = 18:38:28 (JD 2456625.276713)

Epoch 2013 Nov 4.0 TT = JDT 2456600.5 Earth MOID: 0.0578 Ve: 0.0800

q 0.01244157 (2000.0) P Q

M(N) 6.3 K 10.0 Peri. 345.56518 0.31514246 -0.51236211

Node 295.65268 -0.75893961 0.36934200

e 1.0000019 Incl. 62.40011 -0.56982092 -0.77528803

From 3943 observations 2012 Sept. 21-2013 Aug. 23; mean residual 0".586.

# State vector (heliocentric ecliptic J2000):

# -0.392016068734 0.835201958865 0.015674428334 AU

# 9.434225390851 -23.306814310270 -3.032845430140 mAU/day

# MOIDs: Me 0.1702 Ve 0.0800 Ea 0.0578 Ma 0.1487

# MOIDs: Ju 1.4676 Sa 3.1126 Ur 6.9083 Ne 12.1867

# Elements written: 31 Aug 2013 14:54:56 (JD 2456536.121481)

# Full range of obs: 2011 Sept. 30-2013 Aug. 23 (3960 observations)

# Find_Orb ver: Jul 29 2012 19:28:55

# Perturbers: 007007fe (Merc-Pluto plus Luna)

# Tisserand relative to Earth: 0.14601

# Tisserand relative to Jupiter: 0.06326

# Tisserand relative to Neptune: 0.02193

# %20$Name=C/2012%20S1 $Ty=2013 $Tm=11 $Td=28.776712 $MA=359.99995

# $ecc=1.0000020 $Eqnx=2000.

# $a=-6363.7856344 $Peri=345.56518 $Node=295.65268 $Incl=62.40011

# $EpJD=2456600.500 $q=0.012442 $T=2456625.276713 $H=6.2



[Non-text portions of this message have been removed]