| Parameter |
Value |
| Designation |
C/2003 U1 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2003-11-03T09:32:56.417280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:34Z |
| Obs used |
188 |
| NEO |
- |
| M1 |
15.200 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2003-11-05.0000000 |
| e |
0.92158501 |
| q (au) |
1.795717 |
| a (au) |
22.900172 |
| i (deg) |
164.474530 |
| Ω (om, deg) |
322.763107 |
| ω (w, deg) |
278.383793 |
| M (ma, deg) |
0.014409 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.162 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.162 |
| n |
2.000 |
| gf |
0.993 |
| gb |
-1.000 |
| k |
0.990 |
| δ90 |
5.241 |
| 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) |
| 2026-09-20 00:00 |
15:49:08.22 |
-04:24:55.4 |
HIP 77410 |
26.30 |
| 2026-09-20 12:00 |
15:49:09.65 |
-04:25:12.2 |
HIP 77410 |
26.26 |
| 2026-09-21 00:00 |
15:49:11.11 |
-04:25:29.0 |
HIP 77410 |
26.23 |
| 2026-09-21 12:00 |
15:49:12.60 |
-04:25:45.8 |
HIP 77410 |
26.21 |
| 2026-09-22 00:00 |
15:49:14.11 |
-04:26:02.6 |
HIP 77410 |
26.20 |
| 2026-09-22 12:00 |
15:49:15.64 |
-04:26:19.4 |
HIP 77410 |
26.21 |
| 2026-09-23 00:00 |
15:49:17.20 |
-04:26:36.2 |
HIP 77410 |
26.23 |
| 2026-09-23 12:00 |
15:49:18.79 |
-04:26:53.0 |
HIP 77410 |
26.26 |
| 2026-09-24 00:00 |
15:49:20.39 |
-04:27:09.9 |
HIP 77410 |
26.30 |
| 2026-09-24 12:00 |
15:49:22.02 |
-04:27:26.8 |
HIP 77410 |
26.35 |
| 2026-09-25 00:00 |
15:49:23.68 |
-04:27:43.6 |
HIP 77410 |
26.42 |
| 2026-09-25 12:00 |
15:49:25.36 |
-04:28:00.5 |
HIP 77410 |
26.50 |
| 2026-09-26 00:00 |
15:49:27.06 |
-04:28:17.4 |
HIP 77410 |
26.60 |
| 2026-09-26 12:00 |
15:49:28.79 |
-04:28:34.3 |
HIP 77410 |
26.71 |
| 2026-09-27 00:00 |
15:49:30.54 |
-04:28:51.2 |
HIP 77410 |
26.83 |
| 2026-09-27 12:00 |
15:49:32.31 |
-04:29:08.0 |
HIP 77410 |
26.96 |
| 2026-09-28 00:00 |
15:49:34.11 |
-04:29:24.9 |
HIP 77410 |
27.11 |
| 2026-09-28 12:00 |
15:49:35.93 |
-04:29:41.8 |
HIP 77410 |
27.28 |
| 2026-09-29 00:00 |
15:49:37.77 |
-04:29:58.7 |
HIP 77410 |
27.45 |
| 2026-09-29 12:00 |
15:49:39.64 |
-04:30:15.6 |
HIP 77410 |
27.64 |
| 2026-09-30 00:00 |
15:49:41.52 |
-04:30:32.5 |
HIP 77486 |
27.78 |
| 2026-09-30 12:00 |
15:49:43.43 |
-04:30:49.4 |
HIP 77486 |
27.61 |
| 2026-10-01 00:00 |
15:49:45.37 |
-04:31:06.2 |
HIP 77486 |
27.45 |
| 2026-10-01 12:00 |
15:49:47.32 |
-04:31:23.1 |
HIP 77486 |
27.31 |
| 2026-10-02 00:00 |
15:49:49.30 |
-04:31:39.9 |
HIP 77486 |
27.18 |
| 2026-10-02 12:00 |
15:49:51.30 |
-04:31:56.8 |
HIP 77486 |
27.06 |
| 2026-10-03 00:00 |
15:49:53.32 |
-04:32:13.6 |
HIP 77486 |
26.95 |
| 2026-10-03 12:00 |
15:49:55.36 |
-04:32:30.5 |
HIP 77486 |
26.86 |
| 2026-10-04 00:00 |
15:49:57.42 |
-04:32:47.3 |
HIP 77486 |
26.78 |
| 2026-10-04 12:00 |
15:49:59.51 |
-04:33:04.1 |
HIP 77486 |
26.72 |
| 2026-10-05 00:00 |
15:50:01.62 |
-04:33:20.8 |
HIP 77486 |
26.67 |
| 2026-10-05 12:00 |
15:50:03.74 |
-04:33:37.6 |
HIP 77486 |
26.64 |
| 2026-10-06 00:00 |
15:50:05.89 |
-04:33:54.3 |
HIP 77486 |
26.63 |
| 2026-10-06 12:00 |
15:50:08.06 |
-04:34:11.1 |
HIP 77486 |
26.63 |
| 2026-10-07 00:00 |
15:50:10.25 |
-04:34:27.8 |
HIP 77486 |
26.64 |
| 2026-10-07 12:00 |
15:50:12.46 |
-04:34:44.5 |
HIP 77486 |
26.68 |
| 2026-10-08 00:00 |
15:50:14.69 |
-04:35:01.1 |
HIP 77486 |
26.73 |
| 2026-10-08 12:00 |
15:50:16.94 |
-04:35:17.8 |
HIP 77486 |
26.80 |
| 2026-10-09 00:00 |
15:50:19.21 |
-04:35:34.4 |
HIP 77486 |
26.89 |
| 2026-10-09 12:00 |
15:50:21.50 |
-04:35:50.9 |
HIP 77486 |
26.99 |
| 2026-10-10 00:00 |
15:50:23.81 |
-04:36:07.5 |
HIP 77486 |
27.11 |
| 2026-10-10 12:00 |
15:50:26.14 |
-04:36:24.0 |
HIP 77486 |
27.25 |
| 2026-10-11 00:00 |
15:50:28.49 |
-04:36:40.5 |
HIP 77486 |
27.41 |