| Parameter |
Value |
| Designation |
C/2002 L9 (NEAT) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2004-04-05T23:32:55.766400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:17Z |
| Obs used |
330 |
| NEO |
- |
| M1 |
6.100 |
| K1 |
7.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2004-09-27.0000000 |
| e |
0.99841352 |
| q (au) |
7.033001 |
| a (au) |
4433.085954 |
| i (deg) |
68.442088 |
| Ω (om, deg) |
110.451316 |
| ω (w, deg) |
231.428516 |
| M (ma, deg) |
0.000581 |
Magnitude
Scatter + Global Linear
$$
M_a = (-0.494 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
-0.494 |
| n |
6.000 |
| gf |
0.904 |
| gb |
-0.957 |
| k |
1.000 |
| δ90 |
5.038 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2002-06-06 |
2003-10-20 |
+1.1436 |
-1.109 |
| 2004-06-23 |
2006-01-02 |
+6.0714 |
-5.664 |
| 2006-01-02 |
2007-01-11 |
+17.2883 |
-15.484 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
07:23:49.41 |
+22:44:58.9 |
HIP 35842 |
12.72 |
| 2026-03-26 12:00 |
07:23:48.72 |
+22:45:04.0 |
HIP 35842 |
12.59 |
| 2026-03-27 00:00 |
07:23:48.06 |
+22:45:09.0 |
HIP 35842 |
12.45 |
| 2026-03-27 12:00 |
07:23:47.43 |
+22:45:14.0 |
HIP 35842 |
12.32 |
| 2026-03-28 00:00 |
07:23:46.83 |
+22:45:18.9 |
HIP 35842 |
12.20 |
| 2026-03-28 12:00 |
07:23:46.26 |
+22:45:23.8 |
HIP 35842 |
12.07 |
| 2026-03-29 00:00 |
07:23:45.72 |
+22:45:28.6 |
HIP 35842 |
11.96 |
| 2026-03-29 12:00 |
07:23:45.20 |
+22:45:33.3 |
HIP 35842 |
11.84 |
| 2026-03-30 00:00 |
07:23:44.71 |
+22:45:38.0 |
HIP 35842 |
11.73 |
| 2026-03-30 12:00 |
07:23:44.25 |
+22:45:42.6 |
HIP 35842 |
11.62 |
| 2026-03-31 00:00 |
07:23:43.82 |
+22:45:47.2 |
HIP 35842 |
11.52 |
| 2026-03-31 12:00 |
07:23:43.42 |
+22:45:51.7 |
HIP 35842 |
11.42 |
| 2026-04-01 00:00 |
07:23:43.05 |
+22:45:56.1 |
HIP 35842 |
11.32 |
| 2026-04-01 12:00 |
07:23:42.70 |
+22:46:00.5 |
HIP 35842 |
11.23 |
| 2026-04-02 00:00 |
07:23:42.39 |
+22:46:04.8 |
HIP 35842 |
11.14 |
| 2026-04-02 12:00 |
07:23:42.10 |
+22:46:09.1 |
HIP 35842 |
11.05 |
| 2026-04-03 00:00 |
07:23:41.84 |
+22:46:13.3 |
HIP 35842 |
10.97 |
| 2026-04-03 12:00 |
07:23:41.61 |
+22:46:17.4 |
HIP 35842 |
10.89 |
| 2026-04-04 00:00 |
07:23:41.40 |
+22:46:21.5 |
HIP 35842 |
10.81 |
| 2026-04-04 12:00 |
07:23:41.23 |
+22:46:25.5 |
HIP 35842 |
10.73 |
| 2026-04-05 00:00 |
07:23:41.08 |
+22:46:29.5 |
HIP 35842 |
10.66 |
| 2026-04-05 12:00 |
07:23:40.96 |
+22:46:33.4 |
HIP 35842 |
10.59 |
| 2026-04-06 00:00 |
07:23:40.87 |
+22:46:37.3 |
HIP 35842 |
10.52 |
| 2026-04-06 12:00 |
07:23:40.81 |
+22:46:41.0 |
HIP 35842 |
10.46 |
| 2026-04-07 00:00 |
07:23:40.78 |
+22:46:44.8 |
HIP 35842 |
10.39 |
| 2026-04-07 12:00 |
07:23:40.77 |
+22:46:48.5 |
HIP 35842 |
10.34 |
| 2026-04-08 00:00 |
07:23:40.80 |
+22:46:52.1 |
HIP 35842 |
10.28 |
| 2026-04-08 12:00 |
07:23:40.85 |
+22:46:55.6 |
HIP 35842 |
10.23 |
| 2026-04-09 00:00 |
07:23:40.93 |
+22:46:59.1 |
HIP 35842 |
10.18 |
| 2026-04-09 12:00 |
07:23:41.04 |
+22:47:02.6 |
HIP 35842 |
10.13 |
| 2026-04-10 00:00 |
07:23:41.18 |
+22:47:06.0 |
HIP 35842 |
10.08 |
| 2026-04-10 12:00 |
07:23:41.34 |
+22:47:09.3 |
HIP 35842 |
10.04 |
| 2026-04-11 00:00 |
07:23:41.54 |
+22:47:12.6 |
HIP 35842 |
10.00 |
| 2026-04-11 12:00 |
07:23:41.76 |
+22:47:15.8 |
HIP 35842 |
9.97 |
| 2026-04-12 00:00 |
07:23:42.01 |
+22:47:18.9 |
HIP 35842 |
9.94 |
| 2026-04-12 12:00 |
07:23:42.29 |
+22:47:22.0 |
HIP 35842 |
9.91 |
| 2026-04-13 00:00 |
07:23:42.59 |
+22:47:25.1 |
HIP 35842 |
9.88 |
| 2026-04-13 12:00 |
07:23:42.93 |
+22:47:28.0 |
HIP 35842 |
9.86 |
| 2026-04-14 00:00 |
07:23:43.29 |
+22:47:31.0 |
HIP 35842 |
9.85 |
| 2026-04-14 12:00 |
07:23:43.68 |
+22:47:33.8 |
HIP 35842 |
9.84 |
| 2026-04-15 00:00 |
07:23:44.10 |
+22:47:36.6 |
HIP 35842 |
9.83 |
| 2026-04-15 12:00 |
07:23:44.55 |
+22:47:39.4 |
HIP 35842 |
9.82 |
| 2026-04-16 00:00 |
07:23:45.02 |
+22:47:42.1 |
HIP 35842 |
9.83 |