C/2001 O2 (NEAT)
| 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) |
| 2026-02-03 00:00 |
20:14:37.70 |
+44:50:15.4 |
HIP 99698 |
8.21 |
| 2026-02-03 12:00 |
20:14:41.09 |
+44:50:28.9 |
HIP 99698 |
8.81 |
| 2026-02-04 00:00 |
20:14:44.48 |
+44:50:42.7 |
HIP 99698 |
9.42 |
| 2026-02-04 12:00 |
20:14:47.86 |
+44:50:56.8 |
HIP 99698 |
10.03 |
| 2026-02-05 00:00 |
20:14:51.23 |
+44:51:11.2 |
HIP 99698 |
10.64 |
| 2026-02-05 12:00 |
20:14:54.60 |
+44:51:25.9 |
HIP 99698 |
11.25 |
| 2026-02-06 00:00 |
20:14:57.96 |
+44:51:40.9 |
HIP 99698 |
11.87 |
| 2026-02-06 12:00 |
20:15:01.31 |
+44:51:56.1 |
HIP 99698 |
12.49 |
| 2026-02-07 00:00 |
20:15:04.65 |
+44:52:11.6 |
HIP 99698 |
13.11 |
| 2026-02-07 12:00 |
20:15:07.98 |
+44:52:27.4 |
HIP 99698 |
13.73 |
| 2026-02-08 00:00 |
20:15:11.31 |
+44:52:43.5 |
HIP 99698 |
14.35 |
| 2026-02-08 12:00 |
20:15:14.62 |
+44:52:59.9 |
HIP 99698 |
14.98 |
| 2026-02-09 00:00 |
20:15:17.93 |
+44:53:16.5 |
HIP 99698 |
15.60 |
| 2026-02-09 12:00 |
20:15:21.23 |
+44:53:33.4 |
HIP 99698 |
16.23 |
| 2026-02-10 00:00 |
20:15:24.51 |
+44:53:50.6 |
HIP 99698 |
16.85 |
| 2026-02-10 12:00 |
20:15:27.79 |
+44:54:08.0 |
HIP 99698 |
17.48 |
| 2026-02-11 00:00 |
20:15:31.06 |
+44:54:25.8 |
HIP 99698 |
18.11 |
| 2026-02-11 12:00 |
20:15:34.31 |
+44:54:43.8 |
HIP 99698 |
18.74 |
| 2026-02-12 00:00 |
20:15:37.56 |
+44:55:02.1 |
HIP 99698 |
19.37 |
| 2026-02-12 12:00 |
20:15:40.79 |
+44:55:20.6 |
HIP 100019 |
19.68 |
| 2026-02-13 00:00 |
20:15:44.02 |
+44:55:39.4 |
HIP 100019 |
19.14 |
| 2026-02-13 12:00 |
20:15:47.23 |
+44:55:58.5 |
HIP 100019 |
18.61 |
| 2026-02-14 00:00 |
20:15:50.43 |
+44:56:17.9 |
HIP 100019 |
18.09 |
| 2026-02-14 12:00 |
20:15:53.62 |
+44:56:37.5 |
HIP 100019 |
17.58 |
| 2026-02-15 00:00 |
20:15:56.79 |
+44:56:57.4 |
HIP 100019 |
17.09 |
| 2026-02-15 12:00 |
20:15:59.96 |
+44:57:17.5 |
HIP 100019 |
16.61 |
| 2026-02-16 00:00 |
20:16:03.11 |
+44:57:37.9 |
HIP 100019 |
16.14 |
| 2026-02-16 12:00 |
20:16:06.25 |
+44:57:58.6 |
HIP 100019 |
15.69 |
| 2026-02-17 00:00 |
20:16:09.37 |
+44:58:19.5 |
HIP 100019 |
15.26 |
| 2026-02-17 12:00 |
20:16:12.48 |
+44:58:40.7 |
HIP 100019 |
14.85 |
| 2026-02-18 00:00 |
20:16:15.58 |
+44:59:02.2 |
HIP 100019 |
14.46 |
| 2026-02-18 12:00 |
20:16:18.66 |
+44:59:23.9 |
HIP 100019 |
14.10 |
| 2026-02-19 00:00 |
20:16:21.73 |
+44:59:45.8 |
HIP 100019 |
13.76 |
| 2026-02-19 12:00 |
20:16:24.79 |
+45:00:08.0 |
HIP 100019 |
13.45 |
| 2026-02-20 00:00 |
20:16:27.83 |
+45:00:30.5 |
HIP 100019 |
13.17 |
| 2026-02-20 12:00 |
20:16:30.85 |
+45:00:53.2 |
HIP 100019 |
12.92 |
| 2026-02-21 00:00 |
20:16:33.86 |
+45:01:16.1 |
HIP 100019 |
12.70 |
| 2026-02-21 12:00 |
20:16:36.86 |
+45:01:39.3 |
HIP 100019 |
12.52 |
| 2026-02-22 00:00 |
20:16:39.84 |
+45:02:02.7 |
HIP 100019 |
12.38 |
| 2026-02-22 12:00 |
20:16:42.80 |
+45:02:26.4 |
HIP 100019 |
12.27 |
| 2026-02-23 00:00 |
20:16:45.75 |
+45:02:50.3 |
HIP 100019 |
12.21 |
| 2026-02-23 12:00 |
20:16:48.68 |
+45:03:14.4 |
HIP 100019 |
12.18 |
| 2026-02-24 00:00 |
20:16:51.59 |
+45:03:38.8 |
HIP 100019 |
12.19 |