"Pseudo-MPEC" for EPOXI

Created Mon Dec 31 15:36:58 2007 using Find_Orb

Note that to get an orbit, I had to use all but one of the observations from (G96) Mount Lemmon, and exclude those from (595) Farra d'Isonzo. The (595) data has the right motion, but gives positions about 12 arcminutes north of JPL's Horizons ephemeris generator. Also, at the time of the (595) observations, EPOXI should have been somewhere around mag 23 (based on the mags from the other observatories).


 Astrometry 
 Observing stations 
 Orbital elements 
 Residuals 
 Ephemeris 

Astrometry:
EPOXI         C2007 12 27.72975 02 03 14.56 +04 35 41.1         x20.2 V D0131595
EPOXI         C2007 12 27.73664 02 03 13.20 +04 35 35.4         x20.3 V D0131595
EPOXI         C2007 12 27.75476 02 03 09.46 +04 35 18.0         x20.0 V D0131595
EPOXI         C2007 12 27.77547 02 03 05.32 +04 35 00.3         x21.0 V D0131595
EPOXI         C2007 12 27.77978 02 03 04.39 +04 34 57.8         x20.2 V D0131595
EPOXI         C2007 12 30.10579 02 12 01.33 +03 28 26.9          21.6 V D0132G96
EPOXI         C2007 12 30.11166 02 11 59.64 +03 28 07.9          22.5 V D0132G96
EPOXI         C2007 12 30.11756 02 11 57.94 +03 27 48.7          21.1 V D0132G96
EPOXI         C2007 12 30.12341 02 11 56.18 +03 27 29.0          21.0 V D0132G96
EPOXI         C2007 12 30.17869 02 11 39.94 +03 24 08.9                 D0133G96
EPOXI         C2007 12 30.18504 02 11 38.32 +03 23 43.7          20.5 V D0133G96
EPOXI         C2007 12 30.19138 02 11 36.66 +03 23 19.6          20.7 V D0133G96
EPOXI         C2007 12 30.19766 02 11 34.82 +03 22 52.6         x       D0133G96
EPOXI        FC2007 12 30.98515 02 22 53.30 +01 38 52.3          19.9 R D0135204
EPOXI         C2007 12 31.15973 02 32 05.85 +01 07 17.1          19.5 V D0134G96
EPOXI         C2007 12 31.16002 02 32 06.10 +01 07 11.6          19.2 V D0134G96
EPOXI         C2007 12 31.16030 02 32 06.39 +01 07 06.0          19.4 V D0134G96
EPOXI         C2007 12 31.16058 02 32 06.64 +01 07 00.4          19.4 V D0134G96
EPOXI         C2007 12 31.50074602 59 58.04 +00 36 06.8          17.3 R D0135E12
EPOXI         C2007 12 31.50298403 00 13.28 +00 34 27.5          17.4 R D0135E12
EPOXI         C2007 12 31.55281503 07 08.78 -00 08 23.6          17.2 R D0135E12
EPOXI         C2007 12 31.55495303 07 30.55 -00 10 32.0          17.1 R D0135E12

Station data:
(204) Schiaparelli Observatory  (N45.8680 E8.7708).   Observer L. Buzzi.
    0.60-m f/4.64 reflector + CCD.
(595) Farra d'Isonzo (N45.9156 E13.5256).   Observers L. Bittesini, G.
    Lombardi, E. Pettarin, F. Piani, F. Fabris.  Measurers G. Lombardi, E.
    Pettarin, L. Bittesini.  0.40-m f/4.5 reflector + CCD.
(E12) Siding Spring Survey (S31.2735 E149.0642).   Observers E. J.
    Christensen, G. J. Garradd, D. M. Burton, R. H. McNaught.  Measurers E. C.
    Beshore, C. M. Casey, E. J. Christensen, G. J. Garradd, A. D. Grauer, R. E.
    Hill, S. M. Larson, R. H. McNaught, A. R. Gibbs, R. A. Kowalski.  0.5-m
    Uppsala Schmidt + CCD.
(G96) Mt. Lemmon Survey (N32.44283 W110.78872).   Observers E. J. Christensen,
    A. R. Gibbs.  Measurers E. C. Beshore, E. J. Christensen, G. J. Garradd, A.
    R. Gibbs, A. D. Grauer, R. E. Hill, R. A. Kowalski, S. M. Larson, R. H.
    McNaught, R. H.  1.5-m reflector + CCD.

Orbital elements (geocentric,  during flyby):
EPOXI
   Perigee 2007 Dec 31.812770 TT = 19:30:23 (JD 2454466.312770)
Epoch 2007 Dec 31.0 TT = JDT 2454465.5                  Find_Orb
q 21955.9996km           (2000.0)            P               Q
H   31.2  G 0.15   Peri.  291.75116     -0.86989508      0.43438907
                   Node   223.46256      0.47335705      0.86835826
e   1.6551827      Incl.   19.85586     -0.13862045      0.23929071
From 16 observations 2007 Dec. 30-31;   RMS error 0.538 arcseconds

Orbital elements (heliocentric, before flyby): 
EPOXI
   Perihelion 2008 Jan 9.557987 TT = 13:23:30 (JD 2454475.057987)
Epoch 2007 Dec 20.0 TT = JDT 2454454.5   Earth MOID: 0.0001   Ma: 0.0226
M 346.51239              (2000.0)            P               Q
n   0.65607638     Peri.    8.50449     -0.33391640     -0.94253733
a   1.31169574     Node   101.00273      0.86415451     -0.31080823
e   0.2522994      Incl.    0.64789      0.37647949     -0.12256269
P   1.50/548.71d   H   31.2     G   0.15   q 0.98075563  Q 1.64263586
From 16 observations 2007 Dec. 30-31;   RMS error 0.538 arcseconds

Orbital elements (heliocentric, after flyby): 
EPOXI
   Perihelion 2008 Mar 15.578135 TT = 13:52:30 (JD 2454541.078135)
Epoch 2008 Jan 20.0 TT = JDT 2454485.5   Earth MOID: 0.0001
M 305.24001              (2000.0)            P               Q
n   0.98527922     Peri.   84.13885     -0.99555609      0.05996982
a   1.00022222     Node    99.28355     -0.08348314     -0.91879325
e   0.0895581      Incl.    4.21906      0.04357328     -0.39015710
P   1.00/365.37d   H   31.2     G   0.15   q 0.91064415  Q 1.08980029
From 16 observations 2007 Dec. 30-31;   RMS error 0.538 arcseconds

Orbital elements (heliocentric, after flyby): 
EPOXI
   Perigee 2008 Dec 29.989032 TT = 23:44:12 (JD 2454830.489032)
Epoch 2008 Dec 30.0 TT = JDT 2454830.5                  Find_Orb
q590410.518km            (2000.0)            P               Q
H   31.2  G 0.15   Peri.  334.16494     -0.95233969     -0.22729173
                   Node   220.70249     -0.19646087      0.96721285
e  19.4080051      Incl.   18.17742     -0.23334999      0.11330384
From 16 observations 2007 Dec. 30-31;   RMS error 0.538 arcseconds

These last elements are necessarily very rough. They basically just show that EPOXI will indeed be coming around for another flyby next year.


Residuals in arcseconds:
071227 595(38.5+  755+)   071230 G96  .22-  .31+    071231 G96  .03+  .32-
071227 595(36.8+  753+)   071230 G96  .44-  .18-    071231 G96  .20-  .34-
071227 595(31.8+  748+)   071230 G96  .69+  .75-    071231 E12  .06+  .22+
071227 595(30.4+  744+)   071230 G96  .20+  .09+    071231 E12  .33-  .03-
071227 595(29.3+  745+)   071230 G96( 4.3-  1.8-)   071231 E12  .07+  .02-
071230 G96  .29-  .07+    071230 204  .73+  1.1+    071231 E12  .15+  .12+
071230 G96  .27-  .15+    071231 G96  .01+  .55-
071230 G96  .15+  .42+    071231 G96  .35-  .29-

Ephemerides:
Date (UT)  HH   RA              Dec         delta   r     elong mag  '/hr   PA
---- -- -- --  ------------   ------------  ------ ------ ----- ---  ----- -----
2007 12 30 00  02 10 53.659   +03 51 06.31  614444 0.9850 113.8 21.5  4.99 109.6
2007 12 30 01  02 11 12.936   +03 49 23.42  601388 0.9849 113.8 21.5  5.21 109.6
2007 12 30 02  02 11 33.071   +03 47 35.98  588320 0.9849 113.8 21.4  5.45 109.6
2007 12 30 03  02 11 54.120   +03 45 43.66  575239 0.9849 113.8 21.4  5.70 109.6
2007 12 30 04  02 12 16.151   +03 43 46.12  562143 0.9848 113.9 21.3  5.97 109.6
2007 12 30 05  02 12 39.232   +03 41 42.98  549033 0.9848 113.9 21.3  6.26 109.6
2007 12 30 06  02 13 03.444   +03 39 33.82  535908 0.9848 113.9 21.2  6.57 109.6
2007 12 30 07  02 13 28.872   +03 37 18.16  522767 0.9847 114.0 21.2  6.90 109.6
2007 12 30 08  02 13 55.612   +03 34 55.51  509609 0.9847 114.0 21.1  7.26 109.6
2007 12 30 09  02 14 23.769   +03 32 25.28  496433 0.9847 114.1 21.1  7.65 109.6
2007 12 30 10  02 14 53.461   +03 29 46.84  483240 0.9846 114.1 21.0  8.08 109.6
2007 12 30 11  02 15 24.820   +03 26 59.49  470026 0.9846 114.2 20.9  8.54 109.6
2007 12 30 12  02 15 57.992   +03 24 02.42  456793 0.9846 114.2 20.9  9.04 109.6
2007 12 30 13  02 16 33.144   +03 20 54.75  443538 0.9845 114.3 20.8  9.59 109.6
2007 12 30 14  02 17 10.460   +03 17 35.48  430260 0.9845 114.4 20.7 10.19 109.6
2007 12 30 15  02 17 50.151   +03 14 03.46  416958 0.9845 114.5 20.7 10.85 109.6
2007 12 30 16  02 18 32.457   +03 10 17.39  403631 0.9844 114.6 20.6 11.58 109.6
2007 12 30 17  02 19 17.650   +03 06 15.81  390277 0.9844 114.7 20.5 12.38 109.7
2007 12 30 18  02 20 06.044   +03 01 57.01  376894 0.9844 114.8 20.4 13.28 109.7
2007 12 30 19  02 20 57.999   +02 57 19.04  363480 0.9843 114.9 20.4 14.28 109.7
2007 12 30 20  02 21 53.934   +02 52 19.63  350034 0.9843 115.1 20.3 15.39 109.7
2007 12 30 21  02 22 54.335   +02 46 56.13  336552 0.9843 115.2 20.2 16.65 109.7
2007 12 30 22  02 23 59.774   +02 41 05.44  323033 0.9842 115.4 20.1 18.08 109.7
2007 12 30 23  02 25 10.928   +02 34 43.87  309473 0.9842 115.6 20.0 19.69 109.7
2007 12 31 00  02 26 28.600   +02 27 47.06  295870 0.9842 115.8 19.9 21.55 109.7
2007 12 31 01  02 27 53.757   +02 20 09.75  282220 0.9841 116.0 19.8 23.68 109.7
2007 12 31 02  02 29 27.570   +02 11 45.55  268518 0.9841 116.2 19.7 26.16 109.7
2007 12 31 03  02 31 11.473   +02 02 26.65  254760 0.9841 116.5 19.5 29.06 109.8
2007 12 31 04  02 33 07.244   +01 52 03.37  240940 0.9840 116.8 19.4 32.49 109.8
2007 12 31 05  02 35 17.113   +01 40 23.55  227054 0.9840 117.2 19.3 36.59 109.8
2007 12 31 06  02 37 43.920   +01 27 11.72  213093 0.9840 117.6 19.1 41.54 109.8
2007 12 31 07  02 40 31.343   +01 12 07.86  199049 0.9839 118.1 19.0 47.60 109.8
2007 12 31 08  02 43 44.239   +00 54 45.58  184912 0.9839 118.7 18.8 55.16 109.8
2007 12 31 09  02 47 29.161   +00 34 29.33  170673 0.9839 119.3 18.6 64.75 109.8
2007 12 31 10  02 51 55.187   +00 10 30.03  156316 0.9838 120.1 18.4 77.19 109.8
2007 12 31 11  02 57 15.293   -00 18 22.11  141827 0.9838 121.0 18.1 93.76 109.8
2007 12 31 12  03 03 48.737   -00 53 49.84  127186 0.9837 122.1 17.9 116.6 109.8
2007 12 31 13  03 12 05.470   -01 38 31.02  112372 0.9837 123.6 17.6 149.4 109.8
2007 12 31 14  03 22 54.896   -02 36 40.97   97361 0.9837 125.4 17.2 199.0 109.7
2007 12 31 15  03 37 45.030   -03 55 39.74   82133 0.9836 127.8 16.8 279.6 109.5