| Parameter |
Value |
| Designation |
C/2001 O2 (NEAT) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1999-10-17T08:10:25.610880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:10Z |
| Obs used |
73 |
| NEO |
- |
| M1 |
6.600 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2001-09-20.0000000 |
| e |
0.99779815 |
| q (au) |
4.819418 |
| a (au) |
2188.798835 |
| i (deg) |
90.926212 |
| Ω (om, deg) |
328.716022 |
| ω (w, deg) |
280.894802 |
| M (ma, deg) |
0.006773 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.744 + 3.176\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.744 |
| n |
3.176 |
| gf |
0.893 |
| gb |
-0.966 |
| k |
1.000 |
| δ90 |
4.079 |
| 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) |
| 2026-03-26 00:00 |
20:19:09.23 |
+45:34:02.4 |
HIP 100241 |
14.12 |
| 2026-03-26 12:00 |
20:19:10.79 |
+45:34:37.5 |
HIP 100241 |
14.49 |
| 2026-03-27 00:00 |
20:19:12.33 |
+45:35:12.7 |
HIP 100241 |
14.89 |
| 2026-03-27 12:00 |
20:19:13.83 |
+45:35:48.1 |
HIP 100241 |
15.32 |
| 2026-03-28 00:00 |
20:19:15.31 |
+45:36:23.5 |
HIP 100241 |
15.76 |
| 2026-03-28 12:00 |
20:19:16.77 |
+45:36:59.1 |
HIP 100241 |
16.21 |
| 2026-03-29 00:00 |
20:19:18.19 |
+45:37:34.7 |
HIP 100241 |
16.68 |
| 2026-03-29 12:00 |
20:19:19.59 |
+45:38:10.5 |
HIP 100241 |
17.17 |
| 2026-03-30 00:00 |
20:19:20.96 |
+45:38:46.3 |
HIP 100144 |
17.60 |
| 2026-03-30 12:00 |
20:19:22.30 |
+45:39:22.2 |
HIP 100144 |
17.10 |
| 2026-03-31 00:00 |
20:19:23.62 |
+45:39:58.2 |
HIP 100144 |
16.61 |
| 2026-03-31 12:00 |
20:19:24.90 |
+45:40:34.3 |
HIP 100144 |
16.13 |
| 2026-04-01 00:00 |
20:19:26.16 |
+45:41:10.5 |
HIP 100144 |
15.66 |
| 2026-04-01 12:00 |
20:19:27.39 |
+45:41:46.8 |
HIP 100144 |
15.20 |
| 2026-04-02 00:00 |
20:19:28.60 |
+45:42:23.1 |
HIP 100144 |
14.74 |
| 2026-04-02 12:00 |
20:19:29.77 |
+45:42:59.6 |
HIP 100144 |
14.30 |
| 2026-04-03 00:00 |
20:19:30.91 |
+45:43:36.1 |
HIP 100144 |
13.87 |
| 2026-04-03 12:00 |
20:19:32.03 |
+45:44:12.6 |
HIP 100144 |
13.45 |
| 2026-04-04 00:00 |
20:19:33.12 |
+45:44:49.3 |
HIP 100144 |
13.05 |
| 2026-04-04 12:00 |
20:19:34.18 |
+45:45:26.0 |
HIP 100144 |
12.66 |
| 2026-04-05 00:00 |
20:19:35.21 |
+45:46:02.8 |
HIP 100144 |
12.29 |
| 2026-04-05 12:00 |
20:19:36.21 |
+45:46:39.6 |
HIP 100144 |
11.94 |
| 2026-04-06 00:00 |
20:19:37.18 |
+45:47:16.5 |
HIP 100144 |
11.61 |
| 2026-04-06 12:00 |
20:19:38.13 |
+45:47:53.5 |
HIP 100144 |
11.30 |
| 2026-04-07 00:00 |
20:19:39.04 |
+45:48:30.5 |
HIP 100144 |
11.01 |
| 2026-04-07 12:00 |
20:19:39.93 |
+45:49:07.6 |
HIP 100144 |
10.75 |
| 2026-04-08 00:00 |
20:19:40.78 |
+45:49:44.7 |
HIP 100144 |
10.51 |
| 2026-04-08 12:00 |
20:19:41.61 |
+45:50:21.9 |
HIP 100144 |
10.31 |
| 2026-04-09 00:00 |
20:19:42.40 |
+45:50:59.1 |
HIP 100144 |
10.13 |
| 2026-04-09 12:00 |
20:19:43.17 |
+45:51:36.4 |
HIP 100144 |
9.99 |
| 2026-04-10 00:00 |
20:19:43.91 |
+45:52:13.7 |
HIP 100144 |
9.88 |
| 2026-04-10 12:00 |
20:19:44.62 |
+45:52:51.1 |
HIP 100144 |
9.81 |
| 2026-04-11 00:00 |
20:19:45.29 |
+45:53:28.5 |
HIP 100144 |
9.77 |
| 2026-04-11 12:00 |
20:19:45.94 |
+45:54:05.9 |
HIP 100144 |
9.77 |
| 2026-04-12 00:00 |
20:19:46.56 |
+45:54:43.3 |
HIP 100144 |
9.80 |
| 2026-04-12 12:00 |
20:19:47.14 |
+45:55:20.8 |
HIP 100144 |
9.87 |
| 2026-04-13 00:00 |
20:19:47.70 |
+45:55:58.4 |
HIP 100144 |
9.98 |
| 2026-04-13 12:00 |
20:19:48.23 |
+45:56:35.9 |
HIP 100144 |
10.11 |
| 2026-04-14 00:00 |
20:19:48.72 |
+45:57:13.5 |
HIP 100144 |
10.28 |
| 2026-04-14 12:00 |
20:19:49.19 |
+45:57:51.0 |
HIP 100144 |
10.48 |
| 2026-04-15 00:00 |
20:19:49.63 |
+45:58:28.6 |
HIP 100144 |
10.71 |
| 2026-04-15 12:00 |
20:19:50.03 |
+45:59:06.3 |
HIP 100144 |
10.96 |
| 2026-04-16 00:00 |
20:19:50.41 |
+45:59:43.9 |
HIP 100144 |
11.24 |