The tracks of 2378 = 4276 are drawn for the 15th day of each month, all tracks run downward.
The numbers give the velocities in pixel/hour for the C2 1024*1024 images.
SOHO-2378 = SOHO-4276
SOHO-2378 was
found by H. Tan in LASCO C2 images of 2012-10-13/14. The comet
was later visible in LASCO C3. Its peak magnitude was mag 8 in
C2.
SOHO-4276 was found by W. Boonplod in C2 images of 2021-09-11.
Its peak magnitude was mag 7.
With Karl Battams' new measurements in C2 these comets can be linked with small residuals:
2012/10/13 JD=2456214.4089476 (ref. J2000.0) File: 23784276.POS
Ecliptic Oscul. Elements Equat. Pos. & Vel.
(deg, AU) (Gm, km/s)
Itr: 5 Converged s = 1.4620E-03°
e : 0.98225679 s= 7.31E-06 X0 : -5.98658357E+00 s= 3.51E-03
i : 42.63940926 s= 1.51E-02 Y0 : 3.68074446E+00 s= 8.92E-04
w : 206.39932630 s= 1.53E-02 Z0 : -2.22315174E+00 s= 1.17E-03
Nod: 301.46567344 s= 2.41E-02 Vx0: -3.90633026E+01 s= 6.21E-02
a : 2.70829010 s= 3.03E-07 Vy0: -9.87131044E+01 s= 3.70E-02
M0: 0.03101595 Vz0: -1.56244317E+02 s= 4.77E-02
Rj0: -3.28049E-08 Used Observations: 50 Time Span: 3254.917 d
A1: 0.00000000E+00 M. Motion: 0.2211369420 s= 3.71E-08
A2: 0.00000000E+00 Perih Dist : 0.04805376 s= 1.98E-05
A3: 0.00000000E+00 Perih Long : 147.86499975 s= 2.80E-02
AF: 1.11262000E-01 Period (JY): 4.45709 s= 7.47E-07
Perih Time : -0.14026 s= 2.35E-08
Residuals in seconds of arc
No Date Time dRho (Gm) dRA*(") dDec (") dAng (")
4 20121013.908948 2456214.408948 1.388E-17 2.972 2.621 3.963
5 20121013.917288 2456214.417288 0.000E+00 1.495 -3.983 4.254
6 20121013.925618 2456214.425618 1.388E-17 4.927 0.746 4.983
7 20121013.933958 2456214.433958 -1.388E-17 2.652 -2.847 3.891
8 20121013.942288 2456214.442288 0.000E+00 -3.559 -0.141 3.561
9 20121013.967358 2456214.467358 2.776E-17 -0.000 2.111 2.111
10 20121013.975618 2456214.475618 1.388E-17 2.440 0.334 2.463
11 20121013.983948 2456214.483948 1.388E-17 2.950 3.203 4.354
12 20121013.992288 2456214.492288 2.776E-17 2.370 3.637 4.341
13 20121014.000628 2456214.500628 -1.388E-17 -0.619 3.449 3.504
14 20121014.008958 2456214.508958 0.000E+00 3.035 -0.551 3.084
15 20121014.017288 2456214.517288 0.000E+00 2.852 2.804 4.000
16 20121014.025658 2456214.525658 1.388E-17 1.245 5.193 5.341
17 20121014.033948 2456214.533948 0.000E+00 5.886 4.538 7.432
18 20210911.509341 2459469.009341 0.000E+00 1.403 -1.597 2.126
19 20210911.517681 2459469.017681 1.388E-17 9.639 -5.007 10.862
20 20210911.526011 2459469.026011 2.776E-17 11.017 -4.505 11.903
21 20210911.534341 2459469.034341 2.776E-17 5.415 -4.912 7.311
22 20210911.560471 2459469.060471 2.776E-17 -2.166 -3.490 4.108
23 20210911.567811 2459469.067811 0.000E+00 2.597 -5.086 5.711
24 20210911.576021 2459469.076021 -1.388E-17 1.154 -0.893 1.459
25 20210911.584341 2459469.084341 0.000E+00 4.804 -3.516 5.953
26 20210911.592681 2459469.092681 0.000E+00 -0.224 -0.826 0.856
27 20210911.601011 2459469.101011 -2.776E-17 1.433 4.532 4.753
28 20210911.609341 2459469.109341 -4.163E-17 2.180 -1.260 2.519
29 20210911.617681 2459469.117681 0.000E+00 3.389 -0.029 3.389
30 20210911.634421 2459469.134421 2.776E-17 0.834 1.005 1.306
31 20210911.642681 2459469.142681 -1.388E-17 0.548 -4.098 4.134
32 20210911.651011 2459469.151011 1.388E-17 -1.549 -0.065 1.550
33 20210911.659341 2459469.159341 2.776E-17 -4.466 1.651 4.761
34 20210911.667681 2459469.167681 1.388E-17 -2.343 5.227 5.728
35 20210911.676011 2459469.176011 1.388E-17 2.132 0.232 2.144
36 20210911.684351 2459469.184351 1.388E-17 -0.291 -4.958 4.967
37 20210911.692681 2459469.192681 2.776E-17 -7.807 -6.770 10.334
38 20210911.701011 2459469.201011 1.388E-17 -7.071 1.972 7.341
39 20210911.709351 2459469.209351 -1.388E-17 -7.190 4.445 8.454
40 20210911.717671 2459469.217671 0.000E+00 -0.218 1.026 1.049
41 20210911.726011 2459469.226011 -2.776E-17 -0.201 -2.511 2.519
42 20210911.734341 2459469.234341 2.776E-17 -0.681 -3.785 3.846
43 20210911.742681 2459469.242681 0.000E+00 -4.933 3.579 6.094
44 20210911.751011 2459469.251011 1.388E-17 -3.655 4.162 5.539
45 20210911.759341 2459469.259341 1.388E-17 -7.453 2.145 7.755
46 20210911.767691 2459469.267691 1.388E-17 -1.643 1.896 2.509
47 20210911.776011 2459469.276011 -1.388E-17 -6.398 5.425 8.388
48 20210911.784341 2459469.284341 0.000E+00 -1.349 0.489 1.435
49 20210911.792681 2459469.292681 0.000E+00 -2.945 -1.929 3.520
50 20210911.801011 2459469.301011 1.388E-17 1.120 1.772 2.096
51 20210911.809341 2459469.309341 1.388E-17 -4.259 -6.236 7.551
52 20210911.817681 2459469.317681 -1.388E-17 -2.749 5.226 5.905
53 20210911.826011 2459469.326011 1.388E-17 -1.503 -2.235 2.693
RMS ------------------------------ 1.722E-17 4.006 3.414 5.263
Perihelia 1999 - 2026:
Ecliptic Osculating Elements (J2000.0) at JD 2451340.500000 Date: 1999/06/11:00:00:00.00
Body e i w Node q Tiss JD-Tp T0
23784276 0.98147323 44.409344 205.716270 302.567119 0.05012746 2.1200 -0.082583 4.45063699
T = 1999/06/11.08
Ecliptic Osculating Elements (J2000.0) at JD 2452964.500000 Date: 2003/11/21:00:00:00.00
Body e i w Node q Tiss JD-Tp T0
23784276 0.98168859 44.569702 205.651121 302.659665 0.04949519 2.1202 -0.244633 4.44395841
T = 2003/11/21.24
Ecliptic Osculating Elements (J2000.0) at JD 2454588.500000 Date: 2008/05/02:00:00:00.00
Body e i w Node q Tiss JD-Tp T0
23784276 0.98158000 44.341193 205.759399 302.515798 0.04982705 2.1201 -0.075420 4.44909283
T = 2008/05/02.08
Ecliptic Osculating Elements (J2000.0) at JD 2456213.408948 Date: 2012/10/12:21:48:53.07
Body e i w Node q Tiss JD-Tp T0
23784276 0.98225609 42.639409 206.399243 301.465674 0.04805378 2.1199 -0.859743 4.45682534
T = 2012/10/12.86
L/B = 141.5/-17.5
Ecliptic Osculating Elements (J2000.0) at JD 2457842.500000 Date: 2017/03/30:00:00:00.00
Body e i w Node q Tiss JD-Tp T0
23784276 0.98234663 42.574273 206.445940 301.393108 0.04780478 2.1198 -0.315715 4.45629339
T = 2017/03/30.32
Ecliptic Osculating Elements (J2000.0) at JD 2459468.500000 Date: 2021/09/11:00:00:00.00
Body e i w Node q Tiss JD-Tp T0
23784276 0.98259008 42.512856 206.530372 301.351447 0.04711727 2.1197 -0.621238 4.45228571
T = 2021/09/11.62
L/B = 141.6/-17.6
Ecliptic Osculating Elements (J2000.0) at JD 2461094.500000 Date: 2026/02/23:00:00:00.00
Body e i w Node q Tiss JD-Tp T0
23784276 0.98267310 42.400444 206.577704 301.326906 0.04689368 2.1196 -0.879493 4.45244215
T = 2026/02/23.88
SOHO-2378 was observed in C2 from
2012 Oct 13.91 - 14.03 more than one day after perihelion (Oct
12.86).
SOHO-4276 was observed in C2 from 2021 Sep 11.51 - 11.83 around
perhelion (Sep 11.62).
This can explain why the peak brightness was mag 7 in 2021 and
mag 8 in 2012.
The tracks of 2378 = 4276 are drawn for the 15th day of each
month, all tracks run downward.
The numbers
give the velocities in pixel/hour for the C2 1024*1024 images.
In mid-April, -May
and -November the tracks are outside of the C2 field of view.
So the returns of 2003 Nov 21, 2008 May 02 and 2017 March 30 were
unfavourable.
The return of 1999
June 11 looks better (with the track in C2), but nongrav forces
could have changed
the perihelion time by many weeks into mid-May (with the track
outside C2).
So we may have to wait until 2026 February to see additional images of SOHO-2378 = SOHO-4276.