| Parameter |
Value |
| Designation |
C/2005 O1 (NEAT) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2005-05-17T08:50:22.372800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:51Z |
| Obs used |
90 |
| NEO |
- |
| M1 |
7.100 |
| K1 |
17.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2005-08-12.0000000 |
| e |
0.92959218 |
| q (au) |
3.590926 |
| a (au) |
51.001801 |
| i (deg) |
155.981032 |
| Ω (om, deg) |
304.799007 |
| ω (w, deg) |
324.741971 |
| M (ma, deg) |
0.234424 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.819 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.819 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.760 |
| k |
0.800 |
| δ90 |
10.000 |
| 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) |
| 2026-05-12 00:00 |
12:59:29.88 |
+17:34:38.9 |
HIP 63355 |
13.00 |
| 2026-05-12 12:00 |
12:59:26.95 |
+17:34:42.8 |
HIP 63355 |
12.63 |
| 2026-05-13 00:00 |
12:59:24.03 |
+17:34:46.4 |
HIP 63355 |
12.27 |
| 2026-05-13 12:00 |
12:59:21.13 |
+17:34:49.8 |
HIP 63355 |
11.95 |
| 2026-05-14 00:00 |
12:59:18.25 |
+17:34:52.9 |
HIP 63355 |
11.66 |
| 2026-05-14 12:00 |
12:59:15.38 |
+17:34:55.9 |
HIP 63355 |
11.40 |
| 2026-05-15 00:00 |
12:59:12.54 |
+17:34:58.5 |
HIP 63355 |
11.18 |
| 2026-05-15 12:00 |
12:59:09.71 |
+17:35:01.0 |
HIP 63355 |
10.99 |
| 2026-05-16 00:00 |
12:59:06.90 |
+17:35:03.2 |
HIP 63355 |
10.84 |
| 2026-05-16 12:00 |
12:59:04.10 |
+17:35:05.2 |
HIP 63355 |
10.72 |
| 2026-05-17 00:00 |
12:59:01.33 |
+17:35:06.9 |
HIP 63355 |
10.65 |
| 2026-05-17 12:00 |
12:58:58.58 |
+17:35:08.4 |
HIP 63355 |
10.60 |
| 2026-05-18 00:00 |
12:58:55.84 |
+17:35:09.7 |
HIP 63355 |
10.60 |
| 2026-05-18 12:00 |
12:58:53.12 |
+17:35:10.8 |
HIP 63355 |
10.63 |
| 2026-05-19 00:00 |
12:58:50.43 |
+17:35:11.6 |
HIP 63355 |
10.70 |
| 2026-05-19 12:00 |
12:58:47.75 |
+17:35:12.2 |
HIP 63355 |
10.80 |
| 2026-05-20 00:00 |
12:58:45.09 |
+17:35:12.5 |
HIP 63355 |
10.93 |
| 2026-05-20 12:00 |
12:58:42.45 |
+17:35:12.6 |
HIP 63355 |
11.09 |
| 2026-05-21 00:00 |
12:58:39.84 |
+17:35:12.5 |
HIP 63355 |
11.28 |
| 2026-05-21 12:00 |
12:58:37.24 |
+17:35:12.2 |
HIP 63355 |
11.49 |
| 2026-05-22 00:00 |
12:58:34.66 |
+17:35:11.6 |
HIP 63355 |
11.73 |
| 2026-05-22 12:00 |
12:58:32.11 |
+17:35:10.8 |
HIP 63355 |
11.99 |
| 2026-05-23 00:00 |
12:58:29.57 |
+17:35:09.7 |
HIP 63283 |
12.26 |
| 2026-05-23 12:00 |
12:58:27.06 |
+17:35:08.5 |
HIP 63283 |
12.02 |
| 2026-05-24 00:00 |
12:58:24.57 |
+17:35:07.0 |
HIP 63283 |
11.81 |
| 2026-05-24 12:00 |
12:58:22.09 |
+17:35:05.3 |
HIP 63283 |
11.63 |
| 2026-05-25 00:00 |
12:58:19.64 |
+17:35:03.3 |
HIP 63283 |
11.49 |
| 2026-05-25 12:00 |
12:58:17.21 |
+17:35:01.2 |
HIP 63283 |
11.38 |
| 2026-05-26 00:00 |
12:58:14.81 |
+17:34:58.8 |
HIP 63283 |
11.30 |
| 2026-05-26 12:00 |
12:58:12.42 |
+17:34:56.1 |
HIP 63283 |
11.26 |
| 2026-05-27 00:00 |
12:58:10.06 |
+17:34:53.3 |
HIP 63283 |
11.25 |
| 2026-05-27 12:00 |
12:58:07.71 |
+17:34:50.2 |
HIP 63283 |
11.27 |
| 2026-05-28 00:00 |
12:58:05.39 |
+17:34:46.9 |
HIP 63283 |
11.32 |
| 2026-05-28 12:00 |
12:58:03.10 |
+17:34:43.4 |
HIP 63283 |
11.40 |
| 2026-05-29 00:00 |
12:58:00.82 |
+17:34:39.7 |
HIP 63283 |
11.51 |
| 2026-05-29 12:00 |
12:57:58.57 |
+17:34:35.7 |
HIP 63283 |
11.65 |
| 2026-05-30 00:00 |
12:57:56.34 |
+17:34:31.5 |
HIP 63283 |
11.81 |
| 2026-05-30 12:00 |
12:57:54.13 |
+17:34:27.1 |
HIP 63283 |
12.00 |
| 2026-05-31 00:00 |
12:57:51.94 |
+17:34:22.5 |
HIP 63283 |
12.21 |
| 2026-05-31 12:00 |
12:57:49.78 |
+17:34:17.7 |
HIP 63283 |
12.44 |
| 2026-06-01 00:00 |
12:57:47.64 |
+17:34:12.6 |
HIP 63283 |
12.69 |
| 2026-06-01 12:00 |
12:57:45.52 |
+17:34:07.4 |
HIP 63283 |
12.96 |
| 2026-06-02 00:00 |
12:57:43.43 |
+17:34:01.9 |
HIP 63283 |
13.24 |