| 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 |
0.963 |
| gb |
-0.998 |
| k |
1.000 |
| δ90 |
9.997 |
| 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) |
| 2026-09-20 00:00 |
08:13:47.49 |
-04:59:43.8 |
HIP 40323 |
20.61 |
| 2026-09-20 12:00 |
08:13:49.04 |
-05:00:00.3 |
HIP 40323 |
20.84 |
| 2026-09-21 00:00 |
08:13:50.57 |
-05:00:16.7 |
HIP 40323 |
21.07 |
| 2026-09-21 12:00 |
08:13:52.08 |
-05:00:33.2 |
HIP 40323 |
21.31 |
| 2026-09-22 00:00 |
08:13:53.57 |
-05:00:49.7 |
HIP 40323 |
21.56 |
| 2026-09-22 12:00 |
08:13:55.04 |
-05:01:06.2 |
HIP 40323 |
21.82 |
| 2026-09-23 00:00 |
08:13:56.49 |
-05:01:22.8 |
HIP 40323 |
22.08 |
| 2026-09-23 12:00 |
08:13:57.92 |
-05:01:39.4 |
HIP 40323 |
22.35 |
| 2026-09-24 00:00 |
08:13:59.33 |
-05:01:56.0 |
HIP 40323 |
22.63 |
| 2026-09-24 12:00 |
08:14:00.72 |
-05:02:12.6 |
HIP 40323 |
22.91 |
| 2026-09-25 00:00 |
08:14:02.09 |
-05:02:29.2 |
HIP 40323 |
23.20 |
| 2026-09-25 12:00 |
08:14:03.44 |
-05:02:45.9 |
HIP 40323 |
23.49 |
| 2026-09-26 00:00 |
08:14:04.77 |
-05:03:02.6 |
HIP 40323 |
23.78 |
| 2026-09-26 12:00 |
08:14:06.08 |
-05:03:19.3 |
HIP 40460 |
23.87 |
| 2026-09-27 00:00 |
08:14:07.36 |
-05:03:35.9 |
HIP 40460 |
23.61 |
| 2026-09-27 12:00 |
08:14:08.63 |
-05:03:52.7 |
HIP 40460 |
23.36 |
| 2026-09-28 00:00 |
08:14:09.87 |
-05:04:09.4 |
HIP 40460 |
23.12 |
| 2026-09-28 12:00 |
08:14:11.10 |
-05:04:26.1 |
HIP 40460 |
22.89 |
| 2026-09-29 00:00 |
08:14:12.30 |
-05:04:42.8 |
HIP 40460 |
22.67 |
| 2026-09-29 12:00 |
08:14:13.48 |
-05:04:59.6 |
HIP 40460 |
22.46 |
| 2026-09-30 00:00 |
08:14:14.64 |
-05:05:16.3 |
HIP 40460 |
22.26 |
| 2026-09-30 12:00 |
08:14:15.78 |
-05:05:33.1 |
HIP 40460 |
22.07 |
| 2026-10-01 00:00 |
08:14:16.89 |
-05:05:49.8 |
HIP 40460 |
21.90 |
| 2026-10-01 12:00 |
08:14:17.99 |
-05:06:06.6 |
HIP 40460 |
21.73 |
| 2026-10-02 00:00 |
08:14:19.06 |
-05:06:23.3 |
HIP 40460 |
21.57 |
| 2026-10-02 12:00 |
08:14:20.11 |
-05:06:40.1 |
HIP 40460 |
21.43 |
| 2026-10-03 00:00 |
08:14:21.14 |
-05:06:56.8 |
HIP 40460 |
21.30 |
| 2026-10-03 12:00 |
08:14:22.15 |
-05:07:13.5 |
HIP 40460 |
21.17 |
| 2026-10-04 00:00 |
08:14:23.13 |
-05:07:30.3 |
HIP 40460 |
21.06 |
| 2026-10-04 12:00 |
08:14:24.09 |
-05:07:47.0 |
HIP 40460 |
20.96 |
| 2026-10-05 00:00 |
08:14:25.03 |
-05:08:03.7 |
HIP 40460 |
20.87 |
| 2026-10-05 12:00 |
08:14:25.95 |
-05:08:20.4 |
HIP 40460 |
20.79 |
| 2026-10-06 00:00 |
08:14:26.84 |
-05:08:37.1 |
HIP 40460 |
20.72 |
| 2026-10-06 12:00 |
08:14:27.71 |
-05:08:53.8 |
HIP 40460 |
20.67 |
| 2026-10-07 00:00 |
08:14:28.56 |
-05:09:10.5 |
HIP 40460 |
20.62 |
| 2026-10-07 12:00 |
08:14:29.38 |
-05:09:27.1 |
HIP 40460 |
20.59 |
| 2026-10-08 00:00 |
08:14:30.19 |
-05:09:43.7 |
HIP 40460 |
20.56 |
| 2026-10-08 12:00 |
08:14:30.97 |
-05:10:00.3 |
HIP 40460 |
20.55 |
| 2026-10-09 00:00 |
08:14:31.72 |
-05:10:16.9 |
HIP 40460 |
20.54 |
| 2026-10-09 12:00 |
08:14:32.45 |
-05:10:33.5 |
HIP 40460 |
20.55 |
| 2026-10-10 00:00 |
08:14:33.16 |
-05:10:50.0 |
HIP 40460 |
20.56 |
| 2026-10-10 12:00 |
08:14:33.85 |
-05:11:06.5 |
HIP 40460 |
20.58 |
| 2026-10-11 00:00 |
08:14:34.51 |
-05:11:23.0 |
HIP 40460 |
20.62 |