| Parameter |
Value |
| Designation |
C/2003 J1 (NEAT) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2003-10-10T14:30:59.739840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:29Z |
| Obs used |
80 |
| NEO |
- |
| M1 |
11.300 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2003-07-19.0000000 |
| e |
0.99112756 |
| q (au) |
5.125425 |
| a (au) |
577.679266 |
| i (deg) |
98.313465 |
| Ω (om, deg) |
122.033180 |
| ω (w, deg) |
196.028937 |
| M (ma, deg) |
359.994065 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.067 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.067 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.502 |
| k |
1.000 |
| δ90 |
10.000 |
| Parameter |
Symbol |
Range |
Description |
| Absolute magnitude at 1 AU from Sun and Earth |
H0 |
-5 to 20 |
Intrinsic brightness of the comet |
| Photometric slope parameter |
n |
2 to 6 |
Rate of brightness change with heliocentric distance |
| Forward scattering asymmetry factor |
gf |
0.8 to 1 |
Degree of forward scattering |
| Backward scattering asymmetry factor |
gb |
-1 to -0.5 |
Degree of backward scattering |
| Partitioning coefficient |
k |
0.8 to 1 |
Ratio between forward/backward scattering contributions |
| Dust-to-gas brightness ratio |
δ90 |
1 to 10 |
Relative contribution of dust scattering to gas emission |
Reference: EPSC-DPS2025-160
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
08:03:55.96 |
-05:27:34.5 |
HIP 39541 |
13.55 |
| 2026-03-26 12:00 |
08:03:54.76 |
-05:27:09.5 |
HIP 39541 |
13.76 |
| 2026-03-27 00:00 |
08:03:53.59 |
-05:26:44.6 |
HIP 39541 |
13.98 |
| 2026-03-27 12:00 |
08:03:52.45 |
-05:26:19.7 |
HIP 39541 |
14.21 |
| 2026-03-28 00:00 |
08:03:51.32 |
-05:25:54.8 |
HIP 39541 |
14.45 |
| 2026-03-28 12:00 |
08:03:50.22 |
-05:25:29.9 |
HIP 39541 |
14.69 |
| 2026-03-29 00:00 |
08:03:49.15 |
-05:25:05.0 |
HIP 39541 |
14.94 |
| 2026-03-29 12:00 |
08:03:48.10 |
-05:24:40.1 |
HIP 39541 |
15.20 |
| 2026-03-30 00:00 |
08:03:47.08 |
-05:24:15.3 |
HIP 39541 |
15.46 |
| 2026-03-30 12:00 |
08:03:46.07 |
-05:23:50.5 |
HIP 39541 |
15.73 |
| 2026-03-31 00:00 |
08:03:45.10 |
-05:23:25.7 |
HIP 39541 |
16.00 |
| 2026-03-31 12:00 |
08:03:44.15 |
-05:23:00.9 |
HIP 39541 |
16.27 |
| 2026-04-01 00:00 |
08:03:43.22 |
-05:22:36.2 |
HIP 39541 |
16.55 |
| 2026-04-01 12:00 |
08:03:42.31 |
-05:22:11.5 |
HIP 39541 |
16.83 |
| 2026-04-02 00:00 |
08:03:41.43 |
-05:21:46.8 |
HIP 39541 |
17.11 |
| 2026-04-02 12:00 |
08:03:40.58 |
-05:21:22.1 |
HIP 39541 |
17.39 |
| 2026-04-03 00:00 |
08:03:39.75 |
-05:20:57.5 |
HIP 39541 |
17.68 |
| 2026-04-03 12:00 |
08:03:38.94 |
-05:20:32.9 |
HIP 39541 |
17.96 |
| 2026-04-04 00:00 |
08:03:38.16 |
-05:20:08.3 |
HIP 39541 |
18.25 |
| 2026-04-04 12:00 |
08:03:37.41 |
-05:19:43.8 |
HIP 39541 |
18.54 |
| 2026-04-05 00:00 |
08:03:36.68 |
-05:19:19.3 |
HIP 39541 |
18.83 |
| 2026-04-05 12:00 |
08:03:35.97 |
-05:18:54.9 |
HIP 39541 |
19.12 |
| 2026-04-06 00:00 |
08:03:35.29 |
-05:18:30.5 |
HIP 39541 |
19.40 |
| 2026-04-06 12:00 |
08:03:34.63 |
-05:18:06.1 |
HIP 39541 |
19.69 |
| 2026-04-07 00:00 |
08:03:34.00 |
-05:17:41.8 |
HIP 39541 |
19.98 |
| 2026-04-07 12:00 |
08:03:33.39 |
-05:17:17.5 |
HIP 39541 |
20.27 |
| 2026-04-08 00:00 |
08:03:32.81 |
-05:16:53.3 |
HIP 39541 |
20.55 |
| 2026-04-08 12:00 |
08:03:32.25 |
-05:16:29.1 |
HIP 39541 |
20.83 |
| 2026-04-09 00:00 |
08:03:31.72 |
-05:16:05.0 |
HIP 39541 |
21.12 |
| 2026-04-09 12:00 |
08:03:31.21 |
-05:15:40.9 |
HIP 39541 |
21.40 |
| 2026-04-10 00:00 |
08:03:30.73 |
-05:15:16.9 |
HIP 39541 |
21.68 |
| 2026-04-10 12:00 |
08:03:30.27 |
-05:14:52.9 |
HIP 39541 |
21.96 |
| 2026-04-11 00:00 |
08:03:29.84 |
-05:14:29.0 |
HIP 39541 |
22.24 |
| 2026-04-11 12:00 |
08:03:29.43 |
-05:14:05.1 |
HIP 39541 |
22.51 |
| 2026-04-12 00:00 |
08:03:29.05 |
-05:13:41.3 |
HIP 39541 |
22.78 |
| 2026-04-12 12:00 |
08:03:28.69 |
-05:13:17.6 |
HIP 39541 |
23.06 |
| 2026-04-13 00:00 |
08:03:28.36 |
-05:12:53.9 |
HIP 39541 |
23.32 |
| 2026-04-13 12:00 |
08:03:28.05 |
-05:12:30.3 |
HIP 39541 |
23.59 |
| 2026-04-14 00:00 |
08:03:27.77 |
-05:12:06.7 |
HIP 39541 |
23.86 |
| 2026-04-14 12:00 |
08:03:27.51 |
-05:11:43.2 |
HIP 39541 |
24.12 |
| 2026-04-15 00:00 |
08:03:27.28 |
-05:11:19.8 |
HIP 39483 |
24.20 |
| 2026-04-15 12:00 |
08:03:27.07 |
-05:10:56.5 |
HIP 39483 |
23.87 |
| 2026-04-16 00:00 |
08:03:26.89 |
-05:10:33.2 |
HIP 39483 |
23.54 |