C/2002 J4 (NEAT)
| Parameter |
Value |
| Designation |
C/2002 J4 (NEAT) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2003-10-03T04:21:57.335040Z |
| Orbit solution date (soln_date, UTC) |
2025-07-31T12:12:21Z |
| Obs used |
228 |
| NEO |
- |
| M1 |
10.900 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2003-04-06.0000000 |
| e |
0.99989069 |
| q (au) |
3.633732 |
| a (au) |
33243.727305 |
| i (deg) |
46.525144 |
| Ω (om, deg) |
70.884245 |
| ω (w, deg) |
230.709337 |
| M (ma, deg) |
359.999971 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.255 + 3.626\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.255 |
| n |
3.626 |
| gf |
0.984 |
| gb |
-0.894 |
| k |
0.999 |
| δ90 |
9.909 |
| 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) |
| 2026-02-03 00:00 |
05:17:09.66 |
+34:55:12.0 |
HIP 24821 |
25.83 |
| 2026-02-03 12:00 |
05:17:07.69 |
+34:55:04.9 |
HIP 24821 |
26.23 |
| 2026-02-04 00:00 |
05:17:05.74 |
+34:54:57.9 |
HIP 24821 |
26.62 |
| 2026-02-04 12:00 |
05:17:03.83 |
+34:54:50.8 |
HIP 24821 |
27.01 |
| 2026-02-05 00:00 |
05:17:01.94 |
+34:54:43.7 |
HIP 24821 |
27.39 |
| 2026-02-05 12:00 |
05:17:00.07 |
+34:54:36.6 |
HIP 24821 |
27.77 |
| 2026-02-06 00:00 |
05:16:58.23 |
+34:54:29.5 |
HIP 24821 |
28.14 |
| 2026-02-06 12:00 |
05:16:56.42 |
+34:54:22.4 |
HIP 24821 |
28.50 |
| 2026-02-07 00:00 |
05:16:54.64 |
+34:54:15.2 |
HIP 24821 |
28.87 |
| 2026-02-07 12:00 |
05:16:52.88 |
+34:54:08.0 |
HIP 24821 |
29.22 |
| 2026-02-08 00:00 |
05:16:51.15 |
+34:54:00.8 |
HIP 24821 |
29.58 |
| 2026-02-08 12:00 |
05:16:49.45 |
+34:53:53.6 |
HIP 24821 |
29.92 |
| 2026-02-09 00:00 |
05:16:47.78 |
+34:53:46.4 |
HIP 24821 |
30.27 |
| 2026-02-09 12:00 |
05:16:46.13 |
+34:53:39.2 |
HIP 24538 |
30.27 |
| 2026-02-10 00:00 |
05:16:44.51 |
+34:53:31.9 |
HIP 24538 |
30.04 |
| 2026-02-10 12:00 |
05:16:42.92 |
+34:53:24.6 |
HIP 24538 |
29.81 |
| 2026-02-11 00:00 |
05:16:41.36 |
+34:53:17.4 |
HIP 24538 |
29.59 |
| 2026-02-11 12:00 |
05:16:39.82 |
+34:53:10.1 |
HIP 24538 |
29.37 |
| 2026-02-12 00:00 |
05:16:38.31 |
+34:53:02.8 |
HIP 24538 |
29.16 |
| 2026-02-12 12:00 |
05:16:36.84 |
+34:52:55.5 |
HIP 24538 |
28.95 |
| 2026-02-13 00:00 |
05:16:35.39 |
+34:52:48.2 |
HIP 24538 |
28.74 |
| 2026-02-13 12:00 |
05:16:33.96 |
+34:52:40.8 |
HIP 24538 |
28.53 |
| 2026-02-14 00:00 |
05:16:32.57 |
+34:52:33.5 |
HIP 24538 |
28.33 |
| 2026-02-14 12:00 |
05:16:31.21 |
+34:52:26.2 |
HIP 24538 |
28.14 |
| 2026-02-15 00:00 |
05:16:29.87 |
+34:52:18.8 |
HIP 24538 |
27.95 |
| 2026-02-15 12:00 |
05:16:28.57 |
+34:52:11.5 |
HIP 24538 |
27.76 |
| 2026-02-16 00:00 |
05:16:27.29 |
+34:52:04.2 |
HIP 24538 |
27.57 |
| 2026-02-16 12:00 |
05:16:26.04 |
+34:51:56.8 |
HIP 24538 |
27.39 |
| 2026-02-17 00:00 |
05:16:24.82 |
+34:51:49.5 |
HIP 24538 |
27.21 |
| 2026-02-17 12:00 |
05:16:23.63 |
+34:51:42.1 |
HIP 24538 |
27.03 |
| 2026-02-18 00:00 |
05:16:22.47 |
+34:51:34.8 |
HIP 24538 |
26.86 |
| 2026-02-18 12:00 |
05:16:21.34 |
+34:51:27.4 |
HIP 24538 |
26.69 |
| 2026-02-19 00:00 |
05:16:20.24 |
+34:51:20.1 |
HIP 24538 |
26.52 |
| 2026-02-19 12:00 |
05:16:19.17 |
+34:51:12.7 |
HIP 24538 |
26.35 |
| 2026-02-20 00:00 |
05:16:18.13 |
+34:51:05.4 |
HIP 24538 |
26.19 |
| 2026-02-20 12:00 |
05:16:17.12 |
+34:50:58.1 |
HIP 24538 |
26.03 |
| 2026-02-21 00:00 |
05:16:16.14 |
+34:50:50.7 |
HIP 24538 |
25.87 |
| 2026-02-21 12:00 |
05:16:15.19 |
+34:50:43.4 |
HIP 24538 |
25.72 |
| 2026-02-22 00:00 |
05:16:14.27 |
+34:50:36.1 |
HIP 24538 |
25.57 |
| 2026-02-22 12:00 |
05:16:13.38 |
+34:50:28.8 |
HIP 24538 |
25.42 |
| 2026-02-23 00:00 |
05:16:12.51 |
+34:50:21.5 |
HIP 24538 |
25.27 |
| 2026-02-23 12:00 |
05:16:11.68 |
+34:50:14.2 |
HIP 24538 |
25.12 |
| 2026-02-24 00:00 |
05:16:10.88 |
+34:50:06.9 |
HIP 24538 |
24.98 |