| Parameter |
Value |
| Designation |
C/2004 P1 (NEAT) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2003-08-08T17:39:35.953920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:42Z |
| Obs used |
148 |
| NEO |
- |
| M1 |
10.300 |
| K1 |
6.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2004-09-09.0000000 |
| e |
0.99925569 |
| q (au) |
6.013775 |
| a (au) |
8079.698737 |
| i (deg) |
28.816238 |
| Ω (om, deg) |
284.183334 |
| ω (w, deg) |
16.584545 |
| M (ma, deg) |
0.000539 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.537 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.537 |
| n |
2.000 |
| gf |
0.996 |
| gb |
-0.507 |
| k |
1.000 |
| 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 |
05:00:05.26 |
+36:00:29.6 |
HIP 23427 |
25.04 |
| 2026-05-12 12:00 |
05:00:08.73 |
+36:00:27.9 |
HIP 23427 |
24.34 |
| 2026-05-13 00:00 |
05:00:12.21 |
+36:00:26.4 |
HIP 23427 |
23.65 |
| 2026-05-13 12:00 |
05:00:15.70 |
+36:00:24.9 |
HIP 23427 |
22.95 |
| 2026-05-14 00:00 |
05:00:19.20 |
+36:00:23.6 |
HIP 23427 |
22.25 |
| 2026-05-14 12:00 |
05:00:22.72 |
+36:00:22.3 |
HIP 23427 |
21.55 |
| 2026-05-15 00:00 |
05:00:26.25 |
+36:00:21.1 |
HIP 23427 |
20.85 |
| 2026-05-15 12:00 |
05:00:29.78 |
+36:00:20.0 |
HIP 23427 |
20.15 |
| 2026-05-16 00:00 |
05:00:33.33 |
+36:00:19.0 |
HIP 23427 |
19.45 |
| 2026-05-16 12:00 |
05:00:36.89 |
+36:00:18.0 |
HIP 23427 |
18.74 |
| 2026-05-17 00:00 |
05:00:40.45 |
+36:00:17.2 |
HIP 23427 |
18.04 |
| 2026-05-17 12:00 |
05:00:44.03 |
+36:00:16.4 |
HIP 23427 |
17.33 |
| 2026-05-18 00:00 |
05:00:47.62 |
+36:00:15.7 |
HIP 23427 |
16.63 |
| 2026-05-18 12:00 |
05:00:51.21 |
+36:00:15.1 |
HIP 23427 |
15.93 |
| 2026-05-19 00:00 |
05:00:54.82 |
+36:00:14.6 |
HIP 23427 |
15.23 |
| 2026-05-19 12:00 |
05:00:58.43 |
+36:00:14.2 |
HIP 23427 |
14.53 |
| 2026-05-20 00:00 |
05:01:02.05 |
+36:00:13.8 |
HIP 23427 |
13.83 |
| 2026-05-20 12:00 |
05:01:05.68 |
+36:00:13.6 |
HIP 23427 |
13.13 |
| 2026-05-21 00:00 |
05:01:09.32 |
+36:00:13.4 |
HIP 23427 |
12.44 |
| 2026-05-21 12:00 |
05:01:12.96 |
+36:00:13.3 |
HIP 23427 |
11.76 |
| 2026-05-22 00:00 |
05:01:16.62 |
+36:00:13.3 |
HIP 23427 |
11.07 |
| 2026-05-22 12:00 |
05:01:20.28 |
+36:00:13.4 |
HIP 23427 |
10.40 |
| 2026-05-23 00:00 |
05:01:23.94 |
+36:00:13.5 |
HIP 23427 |
9.73 |
| 2026-05-23 12:00 |
05:01:27.62 |
+36:00:13.7 |
HIP 23427 |
9.08 |
| 2026-05-24 00:00 |
05:01:31.30 |
+36:00:14.1 |
HIP 23427 |
8.44 |
| 2026-05-24 12:00 |
05:01:34.99 |
+36:00:14.5 |
HIP 23427 |
7.82 |
| 2026-05-25 00:00 |
05:01:38.68 |
+36:00:14.9 |
HIP 23427 |
7.22 |
| 2026-05-25 12:00 |
05:01:42.38 |
+36:00:15.5 |
HIP 23427 |
6.65 |
| 2026-05-26 00:00 |
05:01:46.08 |
+36:00:16.1 |
HIP 23427 |
6.12 |
| 2026-05-26 12:00 |
05:01:49.79 |
+36:00:16.9 |
HIP 23427 |
5.64 |
| 2026-05-27 00:00 |
05:01:53.51 |
+36:00:17.7 |
HIP 23427 |
5.23 |
| 2026-05-27 12:00 |
05:01:57.23 |
+36:00:18.6 |
HIP 23427 |
4.90 |
| 2026-05-28 00:00 |
05:02:00.95 |
+36:00:19.5 |
HIP 23427 |
4.67 |
| 2026-05-28 12:00 |
05:02:04.68 |
+36:00:20.6 |
HIP 23427 |
4.55 |
| 2026-05-29 00:00 |
05:02:08.42 |
+36:00:21.7 |
HIP 23427 |
4.56 |
| 2026-05-29 12:00 |
05:02:12.15 |
+36:00:22.9 |
HIP 23427 |
4.70 |
| 2026-05-30 00:00 |
05:02:15.90 |
+36:00:24.2 |
HIP 23427 |
4.95 |
| 2026-05-30 12:00 |
05:02:19.64 |
+36:00:25.6 |
HIP 23427 |
5.29 |
| 2026-05-31 00:00 |
05:02:23.39 |
+36:00:27.0 |
HIP 23427 |
5.72 |
| 2026-05-31 12:00 |
05:02:27.14 |
+36:00:28.5 |
HIP 23427 |
6.22 |
| 2026-06-01 00:00 |
05:02:30.90 |
+36:00:30.1 |
HIP 23427 |
6.76 |
| 2026-06-01 12:00 |
05:02:34.66 |
+36:00:31.8 |
HIP 23427 |
7.35 |
| 2026-06-02 00:00 |
05:02:38.42 |
+36:00:33.6 |
HIP 23427 |
7.96 |