| 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) |
| 2026-06-01 00:00 |
20:18:14.95 |
+46:52:38.5 |
HIP 100250 |
17.45 |
| 2026-06-01 12:00 |
20:18:12.58 |
+46:53:06.5 |
HIP 100250 |
17.92 |
| 2026-06-02 00:00 |
20:18:10.19 |
+46:53:34.2 |
HIP 100250 |
18.40 |
| 2026-06-02 12:00 |
20:18:07.78 |
+46:54:01.8 |
HIP 100250 |
18.89 |
| 2026-06-03 00:00 |
20:18:05.34 |
+46:54:29.1 |
HIP 100250 |
19.39 |
| 2026-06-03 12:00 |
20:18:02.88 |
+46:54:56.2 |
HIP 100250 |
19.90 |
| 2026-06-04 00:00 |
20:18:00.39 |
+46:55:23.1 |
HIP 100250 |
20.42 |
| 2026-06-04 12:00 |
20:17:57.88 |
+46:55:49.8 |
HIP 100250 |
20.95 |
| 2026-06-05 00:00 |
20:17:55.34 |
+46:56:16.2 |
HIP 100250 |
21.49 |
| 2026-06-05 12:00 |
20:17:52.78 |
+46:56:42.5 |
HIP 100250 |
22.03 |
| 2026-06-06 00:00 |
20:17:50.20 |
+46:57:08.5 |
HIP 100250 |
22.58 |
| 2026-06-06 12:00 |
20:17:47.59 |
+46:57:34.3 |
HIP 100250 |
23.14 |
| 2026-06-07 00:00 |
20:17:44.96 |
+46:57:59.9 |
HIP 100250 |
23.70 |
| 2026-06-07 12:00 |
20:17:42.30 |
+46:58:25.2 |
HIP 100250 |
24.26 |
| 2026-06-08 00:00 |
20:17:39.62 |
+46:58:50.3 |
HIP 100250 |
24.84 |
| 2026-06-08 12:00 |
20:17:36.92 |
+46:59:15.2 |
HIP 100250 |
25.41 |
| 2026-06-09 00:00 |
20:17:34.20 |
+46:59:39.9 |
HIP 100250 |
25.99 |
| 2026-06-09 12:00 |
20:17:31.45 |
+47:00:04.3 |
HIP 100250 |
26.58 |
| 2026-06-10 00:00 |
20:17:28.68 |
+47:00:28.5 |
HIP 100250 |
27.16 |
| 2026-06-10 12:00 |
20:17:25.89 |
+47:00:52.4 |
HIP 100250 |
27.75 |
| 2026-06-11 00:00 |
20:17:23.08 |
+47:01:16.1 |
HIP 100250 |
28.35 |
| 2026-06-11 12:00 |
20:17:20.24 |
+47:01:39.5 |
HIP 100250 |
28.95 |
| 2026-06-12 00:00 |
20:17:17.39 |
+47:02:02.8 |
HIP 100250 |
29.55 |
| 2026-06-12 12:00 |
20:17:14.51 |
+47:02:25.7 |
HIP 100250 |
30.15 |
| 2026-06-13 00:00 |
20:17:11.61 |
+47:02:48.4 |
HIP 100250 |
30.75 |
| 2026-06-13 12:00 |
20:17:08.69 |
+47:03:10.9 |
HIP 100250 |
31.36 |
| 2026-06-14 00:00 |
20:17:05.74 |
+47:03:33.1 |
HIP 100250 |
31.97 |
| 2026-06-14 12:00 |
20:17:02.78 |
+47:03:55.1 |
HIP 99785 |
32.39 |
| 2026-06-15 00:00 |
20:16:59.80 |
+47:04:16.8 |
HIP 99785 |
31.77 |
| 2026-06-15 12:00 |
20:16:56.79 |
+47:04:38.3 |
HIP 99785 |
31.16 |
| 2026-06-16 00:00 |
20:16:53.77 |
+47:04:59.5 |
HIP 99785 |
30.54 |
| 2026-06-16 12:00 |
20:16:50.73 |
+47:05:20.4 |
HIP 99785 |
29.93 |
| 2026-06-17 00:00 |
20:16:47.66 |
+47:05:41.1 |
HIP 99785 |
29.32 |
| 2026-06-17 12:00 |
20:16:44.58 |
+47:06:01.5 |
HIP 99785 |
28.71 |
| 2026-06-18 00:00 |
20:16:41.48 |
+47:06:21.6 |
HIP 99785 |
28.10 |
| 2026-06-18 12:00 |
20:16:38.36 |
+47:06:41.5 |
HIP 99785 |
27.49 |
| 2026-06-19 00:00 |
20:16:35.22 |
+47:07:01.1 |
HIP 99785 |
26.89 |
| 2026-06-19 12:00 |
20:16:32.06 |
+47:07:20.5 |
HIP 99785 |
26.28 |
| 2026-06-20 00:00 |
20:16:28.88 |
+47:07:39.6 |
HIP 99785 |
25.68 |
| 2026-06-20 12:00 |
20:16:25.69 |
+47:07:58.4 |
HIP 99785 |
25.08 |
| 2026-06-21 00:00 |
20:16:22.48 |
+47:08:16.9 |
HIP 99785 |
24.49 |
| 2026-06-21 12:00 |
20:16:19.25 |
+47:08:35.2 |
HIP 99785 |
23.89 |
| 2026-06-22 00:00 |
20:16:16.01 |
+47:08:53.2 |
HIP 99785 |
23.31 |