C/2002 L9 (NEAT)
| 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) |
| 2026-02-03 00:00 |
07:27:11.53 |
+22:31:25.5 |
HIP 36279 |
15.16 |
| 2026-02-03 12:00 |
07:27:08.55 |
+22:31:35.9 |
HIP 36279 |
15.67 |
| 2026-02-04 00:00 |
07:27:05.57 |
+22:31:46.3 |
HIP 36279 |
16.20 |
| 2026-02-04 12:00 |
07:27:02.61 |
+22:31:56.6 |
HIP 36279 |
16.74 |
| 2026-02-05 00:00 |
07:26:59.66 |
+22:32:06.9 |
HIP 36279 |
17.28 |
| 2026-02-05 12:00 |
07:26:56.73 |
+22:32:17.1 |
HIP 36279 |
17.84 |
| 2026-02-06 00:00 |
07:26:53.81 |
+22:32:27.3 |
HIP 36279 |
18.40 |
| 2026-02-06 12:00 |
07:26:50.90 |
+22:32:37.5 |
HIP 36279 |
18.97 |
| 2026-02-07 00:00 |
07:26:48.01 |
+22:32:47.6 |
HIP 36279 |
19.54 |
| 2026-02-07 12:00 |
07:26:45.13 |
+22:32:57.7 |
HIP 36279 |
20.12 |
| 2026-02-08 00:00 |
07:26:42.27 |
+22:33:07.8 |
HIP 36279 |
20.70 |
| 2026-02-08 12:00 |
07:26:39.42 |
+22:33:17.8 |
HIP 36279 |
21.28 |
| 2026-02-09 00:00 |
07:26:36.59 |
+22:33:27.7 |
HIP 36279 |
21.87 |
| 2026-02-09 12:00 |
07:26:33.77 |
+22:33:37.7 |
HIP 36279 |
22.46 |
| 2026-02-10 00:00 |
07:26:30.97 |
+22:33:47.6 |
HIP 36279 |
23.04 |
| 2026-02-10 12:00 |
07:26:28.18 |
+22:33:57.4 |
HIP 36279 |
23.63 |
| 2026-02-11 00:00 |
07:26:25.42 |
+22:34:07.2 |
HIP 36279 |
24.22 |
| 2026-02-11 12:00 |
07:26:22.66 |
+22:34:17.0 |
HIP 36279 |
24.81 |
| 2026-02-12 00:00 |
07:26:19.93 |
+22:34:26.7 |
HIP 36279 |
25.40 |
| 2026-02-12 12:00 |
07:26:17.21 |
+22:34:36.4 |
HIP 36279 |
25.99 |
| 2026-02-13 00:00 |
07:26:14.51 |
+22:34:46.0 |
HIP 36279 |
26.58 |
| 2026-02-13 12:00 |
07:26:11.83 |
+22:34:55.6 |
HIP 36279 |
27.16 |
| 2026-02-14 00:00 |
07:26:09.16 |
+22:35:05.1 |
HIP 36279 |
27.75 |
| 2026-02-14 12:00 |
07:26:06.52 |
+22:35:14.7 |
HIP 36279 |
28.33 |
| 2026-02-15 00:00 |
07:26:03.89 |
+22:35:24.1 |
HIP 36279 |
28.91 |
| 2026-02-15 12:00 |
07:26:01.28 |
+22:35:33.5 |
HIP 36279 |
29.49 |
| 2026-02-16 00:00 |
07:25:58.69 |
+22:35:42.9 |
HIP 35930 |
29.45 |
| 2026-02-16 12:00 |
07:25:56.11 |
+22:35:52.2 |
HIP 35930 |
28.91 |
| 2026-02-17 00:00 |
07:25:53.56 |
+22:36:01.5 |
HIP 35930 |
28.38 |
| 2026-02-17 12:00 |
07:25:51.03 |
+22:36:10.7 |
HIP 35930 |
27.85 |
| 2026-02-18 00:00 |
07:25:48.51 |
+22:36:19.9 |
HIP 35930 |
27.33 |
| 2026-02-18 12:00 |
07:25:46.02 |
+22:36:29.0 |
HIP 35930 |
26.82 |
| 2026-02-19 00:00 |
07:25:43.54 |
+22:36:38.1 |
HIP 35930 |
26.32 |
| 2026-02-19 12:00 |
07:25:41.09 |
+22:36:47.1 |
HIP 35930 |
25.82 |
| 2026-02-20 00:00 |
07:25:38.65 |
+22:36:56.1 |
HIP 35930 |
25.33 |
| 2026-02-20 12:00 |
07:25:36.24 |
+22:37:05.0 |
HIP 35930 |
24.85 |
| 2026-02-21 00:00 |
07:25:33.85 |
+22:37:13.9 |
HIP 35930 |
24.37 |
| 2026-02-21 12:00 |
07:25:31.48 |
+22:37:22.7 |
HIP 35930 |
23.90 |
| 2026-02-22 00:00 |
07:25:29.13 |
+22:37:31.5 |
HIP 35930 |
23.45 |
| 2026-02-22 12:00 |
07:25:26.80 |
+22:37:40.2 |
HIP 35930 |
22.99 |
| 2026-02-23 00:00 |
07:25:24.49 |
+22:37:48.9 |
HIP 35930 |
22.55 |
| 2026-02-23 12:00 |
07:25:22.20 |
+22:37:57.6 |
HIP 35930 |
22.12 |
| 2026-02-24 00:00 |
07:25:19.94 |
+22:38:06.1 |
HIP 35930 |
21.69 |