| Parameter |
Value |
| Designation |
C/1992 U1 (Shoemaker) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1993-03-25T16:18:34.217280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:44Z |
| Obs used |
212 |
| NEO |
- |
| M1 |
9.200 |
| K1 |
11.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1993-02-25.0000000 |
| e |
0.99944533 |
| q (au) |
2.313656 |
| a (au) |
4171.194372 |
| i (deg) |
65.985593 |
| Ω (om, deg) |
55.299020 |
| ω (w, deg) |
54.864153 |
| M (ma, deg) |
359.999895 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.951 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.951 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.664 |
| 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) |
| 2026-09-20 00:00 |
15:59:00.57 |
-49:44:41.0 |
HIP 78318 |
9.35 |
| 2026-09-20 12:00 |
15:59:02.00 |
-49:44:30.9 |
HIP 78318 |
9.09 |
| 2026-09-21 00:00 |
15:59:03.45 |
-49:44:20.8 |
HIP 78318 |
8.83 |
| 2026-09-21 12:00 |
15:59:04.93 |
-49:44:10.9 |
HIP 78318 |
8.57 |
| 2026-09-22 00:00 |
15:59:06.43 |
-49:44:01.0 |
HIP 78318 |
8.32 |
| 2026-09-22 12:00 |
15:59:07.96 |
-49:43:51.3 |
HIP 78318 |
8.06 |
| 2026-09-23 00:00 |
15:59:09.50 |
-49:43:41.7 |
HIP 78318 |
7.81 |
| 2026-09-23 12:00 |
15:59:11.08 |
-49:43:32.1 |
HIP 78318 |
7.57 |
| 2026-09-24 00:00 |
15:59:12.67 |
-49:43:22.7 |
HIP 78318 |
7.33 |
| 2026-09-24 12:00 |
15:59:14.29 |
-49:43:13.4 |
HIP 78318 |
7.09 |
| 2026-09-25 00:00 |
15:59:15.93 |
-49:43:04.2 |
HIP 78318 |
6.86 |
| 2026-09-25 12:00 |
15:59:17.59 |
-49:42:55.1 |
HIP 78318 |
6.63 |
| 2026-09-26 00:00 |
15:59:19.28 |
-49:42:46.1 |
HIP 78318 |
6.42 |
| 2026-09-26 12:00 |
15:59:20.99 |
-49:42:37.2 |
HIP 78318 |
6.21 |
| 2026-09-27 00:00 |
15:59:22.72 |
-49:42:28.4 |
HIP 78318 |
6.02 |
| 2026-09-27 12:00 |
15:59:24.47 |
-49:42:19.7 |
HIP 78318 |
5.83 |
| 2026-09-28 00:00 |
15:59:26.25 |
-49:42:11.1 |
HIP 78318 |
5.66 |
| 2026-09-28 12:00 |
15:59:28.05 |
-49:42:02.7 |
HIP 78318 |
5.50 |
| 2026-09-29 00:00 |
15:59:29.87 |
-49:41:54.3 |
HIP 78318 |
5.36 |
| 2026-09-29 12:00 |
15:59:31.71 |
-49:41:46.1 |
HIP 78318 |
5.24 |
| 2026-09-30 00:00 |
15:59:33.57 |
-49:41:38.0 |
HIP 78318 |
5.14 |
| 2026-09-30 12:00 |
15:59:35.46 |
-49:41:30.0 |
HIP 78318 |
5.07 |
| 2026-10-01 00:00 |
15:59:37.36 |
-49:41:22.1 |
HIP 78318 |
5.01 |
| 2026-10-01 12:00 |
15:59:39.29 |
-49:41:14.3 |
HIP 78318 |
4.98 |
| 2026-10-02 00:00 |
15:59:41.24 |
-49:41:06.6 |
HIP 78318 |
4.98 |
| 2026-10-02 12:00 |
15:59:43.21 |
-49:40:59.1 |
HIP 78318 |
5.00 |
| 2026-10-03 00:00 |
15:59:45.20 |
-49:40:51.7 |
HIP 78318 |
5.05 |
| 2026-10-03 12:00 |
15:59:47.22 |
-49:40:44.3 |
HIP 78318 |
5.13 |
| 2026-10-04 00:00 |
15:59:49.25 |
-49:40:37.1 |
HIP 78318 |
5.23 |
| 2026-10-04 12:00 |
15:59:51.31 |
-49:40:30.0 |
HIP 78318 |
5.36 |
| 2026-10-05 00:00 |
15:59:53.38 |
-49:40:23.1 |
HIP 78318 |
5.51 |
| 2026-10-05 12:00 |
15:59:55.48 |
-49:40:16.2 |
HIP 78318 |
5.68 |
| 2026-10-06 00:00 |
15:59:57.59 |
-49:40:09.5 |
HIP 78318 |
5.88 |
| 2026-10-06 12:00 |
15:59:59.73 |
-49:40:02.9 |
HIP 78318 |
6.09 |
| 2026-10-07 00:00 |
16:00:01.88 |
-49:39:56.4 |
HIP 78318 |
6.32 |
| 2026-10-07 12:00 |
16:00:04.06 |
-49:39:50.1 |
HIP 78318 |
6.56 |
| 2026-10-08 00:00 |
16:00:06.26 |
-49:39:43.8 |
HIP 78318 |
6.82 |
| 2026-10-08 12:00 |
16:00:08.47 |
-49:39:37.7 |
HIP 78318 |
7.10 |
| 2026-10-09 00:00 |
16:00:10.71 |
-49:39:31.7 |
HIP 78318 |
7.39 |
| 2026-10-09 12:00 |
16:00:12.96 |
-49:39:25.8 |
HIP 78318 |
7.68 |
| 2026-10-10 00:00 |
16:00:15.23 |
-49:39:20.1 |
HIP 78318 |
7.99 |
| 2026-10-10 12:00 |
16:00:17.52 |
-49:39:14.4 |
HIP 78318 |
8.31 |
| 2026-10-11 00:00 |
16:00:19.84 |
-49:39:08.9 |
HIP 78318 |
8.64 |