| Parameter |
Value |
| Designation |
C/2003 E1 (NEAT) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2004-02-13T14:31:17.322240Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:26Z |
| Obs used |
235 |
| NEO |
- |
| M1 |
13.700 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2003-10-15.0000000 |
| e |
0.76358329 |
| q (au) |
3.244959 |
| a (au) |
13.725590 |
| i (deg) |
33.537820 |
| Ω (om, deg) |
137.069987 |
| ω (w, deg) |
103.859277 |
| M (ma, deg) |
357.643002 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.327 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.327 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2003-03-09 |
2004-02-05 |
+11.2722 |
-7.341 |
| 2004-02-21 |
2004-09-11 |
+21.5365 |
-11.046 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
04:09:26.49 |
-11:22:36.4 |
HIP 19506 |
19.24 |
| 2026-05-12 12:00 |
04:09:31.54 |
-11:22:14.4 |
HIP 19506 |
17.96 |
| 2026-05-13 00:00 |
04:09:36.60 |
-11:21:52.7 |
HIP 19506 |
16.69 |
| 2026-05-13 12:00 |
04:09:41.67 |
-11:21:31.2 |
HIP 19506 |
15.41 |
| 2026-05-14 00:00 |
04:09:46.74 |
-11:21:10.1 |
HIP 19506 |
14.14 |
| 2026-05-14 12:00 |
04:09:51.82 |
-11:20:49.2 |
HIP 19506 |
12.87 |
| 2026-05-15 00:00 |
04:09:56.91 |
-11:20:28.6 |
HIP 19506 |
11.61 |
| 2026-05-15 12:00 |
04:10:02.01 |
-11:20:08.4 |
HIP 19506 |
10.35 |
| 2026-05-16 00:00 |
04:10:07.11 |
-11:19:48.4 |
HIP 19506 |
9.09 |
| 2026-05-16 12:00 |
04:10:12.22 |
-11:19:28.7 |
HIP 19506 |
7.85 |
| 2026-05-17 00:00 |
04:10:17.33 |
-11:19:09.4 |
HIP 19506 |
6.63 |
| 2026-05-17 12:00 |
04:10:22.45 |
-11:18:50.3 |
HIP 19506 |
5.43 |
| 2026-05-18 00:00 |
04:10:27.58 |
-11:18:31.6 |
HIP 19506 |
4.29 |
| 2026-05-18 12:00 |
04:10:32.71 |
-11:18:13.1 |
HIP 19506 |
3.27 |
| 2026-05-19 00:00 |
04:10:37.85 |
-11:17:54.9 |
HIP 19506 |
2.51 |
| 2026-05-19 12:00 |
04:10:42.99 |
-11:17:37.1 |
HIP 19506 |
2.29 |
| 2026-05-20 00:00 |
04:10:48.13 |
-11:17:19.5 |
HIP 19506 |
2.74 |
| 2026-05-20 12:00 |
04:10:53.28 |
-11:17:02.3 |
HIP 19506 |
3.61 |
| 2026-05-21 00:00 |
04:10:58.43 |
-11:16:45.4 |
HIP 19506 |
4.69 |
| 2026-05-21 12:00 |
04:11:03.59 |
-11:16:28.7 |
HIP 19506 |
5.85 |
| 2026-05-22 00:00 |
04:11:08.75 |
-11:16:12.4 |
HIP 19506 |
7.05 |
| 2026-05-22 12:00 |
04:11:13.91 |
-11:15:56.4 |
HIP 19506 |
8.28 |
| 2026-05-23 00:00 |
04:11:19.07 |
-11:15:40.7 |
HIP 19506 |
9.53 |
| 2026-05-23 12:00 |
04:11:24.23 |
-11:15:25.3 |
HIP 19506 |
10.78 |
| 2026-05-24 00:00 |
04:11:29.40 |
-11:15:10.3 |
HIP 19506 |
12.04 |
| 2026-05-24 12:00 |
04:11:34.57 |
-11:14:55.5 |
HIP 19506 |
13.31 |
| 2026-05-25 00:00 |
04:11:39.74 |
-11:14:41.0 |
HIP 19506 |
14.58 |
| 2026-05-25 12:00 |
04:11:44.91 |
-11:14:26.9 |
HIP 19506 |
15.85 |
| 2026-05-26 00:00 |
04:11:50.08 |
-11:14:13.1 |
HIP 19506 |
17.12 |
| 2026-05-26 12:00 |
04:11:55.25 |
-11:13:59.5 |
HIP 19678 |
16.37 |
| 2026-05-27 00:00 |
04:12:00.42 |
-11:13:46.3 |
HIP 19678 |
15.13 |
| 2026-05-27 12:00 |
04:12:05.59 |
-11:13:33.4 |
HIP 19678 |
13.89 |
| 2026-05-28 00:00 |
04:12:10.75 |
-11:13:20.9 |
HIP 19678 |
12.67 |
| 2026-05-28 12:00 |
04:12:15.92 |
-11:13:08.6 |
HIP 19678 |
11.46 |
| 2026-05-29 00:00 |
04:12:21.09 |
-11:12:56.7 |
HIP 19678 |
10.28 |
| 2026-05-29 12:00 |
04:12:26.25 |
-11:12:45.0 |
HIP 19678 |
9.12 |
| 2026-05-30 00:00 |
04:12:31.42 |
-11:12:33.7 |
HIP 19678 |
8.01 |
| 2026-05-30 12:00 |
04:12:36.58 |
-11:12:22.7 |
HIP 19678 |
6.96 |
| 2026-05-31 00:00 |
04:12:41.74 |
-11:12:12.0 |
HIP 19678 |
6.00 |
| 2026-05-31 12:00 |
04:12:46.90 |
-11:12:01.7 |
HIP 19678 |
5.19 |
| 2026-06-01 00:00 |
04:12:52.05 |
-11:11:51.6 |
HIP 19678 |
4.60 |
| 2026-06-01 12:00 |
04:12:57.20 |
-11:11:41.9 |
HIP 19678 |
4.32 |
| 2026-06-02 00:00 |
04:13:02.35 |
-11:11:32.5 |
HIP 19678 |
4.41 |