| 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
$$
M_a = (16.164 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.164 |
| n |
2.000 |
| gf |
0.993 |
| gb |
-1.000 |
| k |
0.990 |
| δ90 |
5.177 |
| 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 |
15:57:13.21 |
-04:09:03.0 |
HIP 78089 |
9.54 |
| 2026-05-12 12:00 |
15:57:09.51 |
-04:08:49.0 |
HIP 78089 |
8.92 |
| 2026-05-13 00:00 |
15:57:05.81 |
-04:08:35.0 |
HIP 78089 |
8.37 |
| 2026-05-13 12:00 |
15:57:02.10 |
-04:08:21.3 |
HIP 78089 |
7.90 |
| 2026-05-14 00:00 |
15:56:58.38 |
-04:08:07.6 |
HIP 78089 |
7.51 |
| 2026-05-14 12:00 |
15:56:54.66 |
-04:07:54.0 |
HIP 78089 |
7.23 |
| 2026-05-15 00:00 |
15:56:50.93 |
-04:07:40.6 |
HIP 78089 |
7.07 |
| 2026-05-15 12:00 |
15:56:47.20 |
-04:07:27.2 |
HIP 78089 |
7.02 |
| 2026-05-16 00:00 |
15:56:43.47 |
-04:07:14.0 |
HIP 78089 |
7.11 |
| 2026-05-16 12:00 |
15:56:39.73 |
-04:07:00.9 |
HIP 78089 |
7.32 |
| 2026-05-17 00:00 |
15:56:35.99 |
-04:06:47.9 |
HIP 78089 |
7.64 |
| 2026-05-17 12:00 |
15:56:32.25 |
-04:06:35.1 |
HIP 78089 |
8.07 |
| 2026-05-18 00:00 |
15:56:28.51 |
-04:06:22.4 |
HIP 78089 |
8.57 |
| 2026-05-18 12:00 |
15:56:24.76 |
-04:06:09.7 |
HIP 78089 |
9.15 |
| 2026-05-19 00:00 |
15:56:21.01 |
-04:05:57.3 |
HIP 78089 |
9.79 |
| 2026-05-19 12:00 |
15:56:17.26 |
-04:05:44.9 |
HIP 78089 |
10.47 |
| 2026-05-20 00:00 |
15:56:13.51 |
-04:05:32.7 |
HIP 78089 |
11.20 |
| 2026-05-20 12:00 |
15:56:09.76 |
-04:05:20.6 |
HIP 78089 |
11.95 |
| 2026-05-21 00:00 |
15:56:06.00 |
-04:05:08.6 |
HIP 78089 |
12.73 |
| 2026-05-21 12:00 |
15:56:02.25 |
-04:04:56.7 |
HIP 78089 |
13.53 |
| 2026-05-22 00:00 |
15:55:58.50 |
-04:04:45.0 |
HIP 78089 |
14.35 |
| 2026-05-22 12:00 |
15:55:54.74 |
-04:04:33.4 |
HIP 78089 |
15.18 |
| 2026-05-23 00:00 |
15:55:50.99 |
-04:04:21.9 |
HIP 78089 |
16.03 |
| 2026-05-23 12:00 |
15:55:47.24 |
-04:04:10.6 |
HIP 78089 |
16.89 |
| 2026-05-24 00:00 |
15:55:43.49 |
-04:03:59.4 |
HIP 78089 |
17.75 |
| 2026-05-24 12:00 |
15:55:39.74 |
-04:03:48.3 |
HIP 78089 |
18.62 |
| 2026-05-25 00:00 |
15:55:35.99 |
-04:03:37.4 |
HIP 78089 |
19.50 |
| 2026-05-25 12:00 |
15:55:32.25 |
-04:03:26.6 |
HIP 78089 |
20.38 |
| 2026-05-26 00:00 |
15:55:28.50 |
-04:03:15.9 |
HIP 77899 |
20.05 |
| 2026-05-26 12:00 |
15:55:24.76 |
-04:03:05.4 |
HIP 77899 |
19.50 |
| 2026-05-27 00:00 |
15:55:21.02 |
-04:02:55.0 |
HIP 77899 |
18.97 |
| 2026-05-27 12:00 |
15:55:17.28 |
-04:02:44.7 |
HIP 77899 |
18.48 |
| 2026-05-28 00:00 |
15:55:13.55 |
-04:02:34.6 |
HIP 77899 |
18.02 |
| 2026-05-28 12:00 |
15:55:09.82 |
-04:02:24.6 |
HIP 77899 |
17.61 |
| 2026-05-29 00:00 |
15:55:06.10 |
-04:02:14.7 |
HIP 77899 |
17.23 |
| 2026-05-29 12:00 |
15:55:02.37 |
-04:02:05.0 |
HIP 77899 |
16.89 |
| 2026-05-30 00:00 |
15:54:58.66 |
-04:01:55.4 |
HIP 77899 |
16.60 |
| 2026-05-30 12:00 |
15:54:54.94 |
-04:01:46.0 |
HIP 77899 |
16.36 |
| 2026-05-31 00:00 |
15:54:51.24 |
-04:01:36.7 |
HIP 77899 |
16.16 |
| 2026-05-31 12:00 |
15:54:47.53 |
-04:01:27.5 |
HIP 77899 |
16.02 |
| 2026-06-01 00:00 |
15:54:43.83 |
-04:01:18.5 |
HIP 77899 |
15.93 |
| 2026-06-01 12:00 |
15:54:40.14 |
-04:01:09.6 |
HIP 77899 |
15.89 |
| 2026-06-02 00:00 |
15:54:36.45 |
-04:01:00.9 |
HIP 77899 |
15.90 |