| 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) |
| 2026-05-12 00:00 |
05:19:38.22 |
+34:39:18.6 |
HIP 24821 |
14.88 |
| 2026-05-12 12:00 |
05:19:41.25 |
+34:39:18.9 |
HIP 24821 |
15.09 |
| 2026-05-13 00:00 |
05:19:44.29 |
+34:39:19.3 |
HIP 24821 |
15.31 |
| 2026-05-13 12:00 |
05:19:47.35 |
+34:39:19.8 |
HIP 24821 |
15.56 |
| 2026-05-14 00:00 |
05:19:50.42 |
+34:39:20.4 |
HIP 24821 |
15.83 |
| 2026-05-14 12:00 |
05:19:53.51 |
+34:39:21.0 |
HIP 24821 |
16.11 |
| 2026-05-15 00:00 |
05:19:56.61 |
+34:39:21.7 |
HIP 24821 |
16.42 |
| 2026-05-15 12:00 |
05:19:59.71 |
+34:39:22.5 |
HIP 24821 |
16.75 |
| 2026-05-16 00:00 |
05:20:02.84 |
+34:39:23.4 |
HIP 24821 |
17.10 |
| 2026-05-16 12:00 |
05:20:05.97 |
+34:39:24.3 |
HIP 24821 |
17.46 |
| 2026-05-17 00:00 |
05:20:09.11 |
+34:39:25.2 |
HIP 24821 |
17.84 |
| 2026-05-17 12:00 |
05:20:12.27 |
+34:39:26.3 |
HIP 25030 |
17.90 |
| 2026-05-18 00:00 |
05:20:15.43 |
+34:39:27.4 |
HIP 25030 |
17.27 |
| 2026-05-18 12:00 |
05:20:18.61 |
+34:39:28.6 |
HIP 25030 |
16.64 |
| 2026-05-19 00:00 |
05:20:21.80 |
+34:39:29.8 |
HIP 25030 |
16.01 |
| 2026-05-19 12:00 |
05:20:25.00 |
+34:39:31.2 |
HIP 25030 |
15.39 |
| 2026-05-20 00:00 |
05:20:28.21 |
+34:39:32.5 |
HIP 25030 |
14.76 |
| 2026-05-20 12:00 |
05:20:31.42 |
+34:39:34.0 |
HIP 25030 |
14.13 |
| 2026-05-21 00:00 |
05:20:34.65 |
+34:39:35.5 |
HIP 25030 |
13.50 |
| 2026-05-21 12:00 |
05:20:37.89 |
+34:39:37.1 |
HIP 25030 |
12.88 |
| 2026-05-22 00:00 |
05:20:41.14 |
+34:39:38.8 |
HIP 25030 |
12.25 |
| 2026-05-22 12:00 |
05:20:44.39 |
+34:39:40.5 |
HIP 25030 |
11.63 |
| 2026-05-23 00:00 |
05:20:47.66 |
+34:39:42.3 |
HIP 25030 |
11.02 |
| 2026-05-23 12:00 |
05:20:50.93 |
+34:39:44.1 |
HIP 25030 |
10.41 |
| 2026-05-24 00:00 |
05:20:54.21 |
+34:39:46.1 |
HIP 25030 |
9.80 |
| 2026-05-24 12:00 |
05:20:57.50 |
+34:39:48.1 |
HIP 25030 |
9.20 |
| 2026-05-25 00:00 |
05:21:00.80 |
+34:39:50.1 |
HIP 25030 |
8.61 |
| 2026-05-25 12:00 |
05:21:04.10 |
+34:39:52.3 |
HIP 25030 |
8.04 |
| 2026-05-26 00:00 |
05:21:07.41 |
+34:39:54.5 |
HIP 25030 |
7.48 |
| 2026-05-26 12:00 |
05:21:10.73 |
+34:39:56.7 |
HIP 25030 |
6.94 |
| 2026-05-27 00:00 |
05:21:14.06 |
+34:39:59.1 |
HIP 25030 |
6.42 |
| 2026-05-27 12:00 |
05:21:17.39 |
+34:40:01.5 |
HIP 25030 |
5.94 |
| 2026-05-28 00:00 |
05:21:20.73 |
+34:40:03.9 |
HIP 25030 |
5.50 |
| 2026-05-28 12:00 |
05:21:24.08 |
+34:40:06.5 |
HIP 25030 |
5.11 |
| 2026-05-29 00:00 |
05:21:27.44 |
+34:40:09.1 |
HIP 25030 |
4.79 |
| 2026-05-29 12:00 |
05:21:30.79 |
+34:40:11.7 |
HIP 25030 |
4.56 |
| 2026-05-30 00:00 |
05:21:34.16 |
+34:40:14.5 |
HIP 25030 |
4.41 |
| 2026-05-30 12:00 |
05:21:37.53 |
+34:40:17.3 |
HIP 25030 |
4.37 |
| 2026-05-31 00:00 |
05:21:40.91 |
+34:40:20.1 |
HIP 25030 |
4.45 |
| 2026-05-31 12:00 |
05:21:44.29 |
+34:40:23.1 |
HIP 25030 |
4.62 |
| 2026-06-01 00:00 |
05:21:47.67 |
+34:40:26.1 |
HIP 25030 |
4.89 |
| 2026-06-01 12:00 |
05:21:51.07 |
+34:40:29.1 |
HIP 25030 |
5.24 |
| 2026-06-02 00:00 |
05:21:54.46 |
+34:40:32.3 |
HIP 25030 |
5.65 |