| Parameter |
Value |
| Designation |
P/2010 UH55 (Spacewatch) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2011-05-10T08:39:59.212800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:46Z |
| Obs used |
164 |
| NEO |
- |
| M1 |
7.100 |
| K1 |
18.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-04-26.0000000 |
| e |
0.57513428 |
| q (au) |
2.767968 |
| a (au) |
6.514923 |
| i (deg) |
8.662558 |
| Ω (om, deg) |
235.264395 |
| ω (w, deg) |
221.618059 |
| M (ma, deg) |
359.148807 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.633 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.633 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.563 |
| 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) |
| 2026-05-12 00:00 |
23:36:07.29 |
+04:40:41.2 |
HIP 116459 |
20.99 |
| 2026-05-12 12:00 |
23:36:24.34 |
+04:42:51.1 |
HIP 116459 |
20.14 |
| 2026-05-13 00:00 |
23:36:41.31 |
+04:45:00.6 |
HIP 116459 |
20.40 |
| 2026-05-13 12:00 |
23:36:58.20 |
+04:47:09.9 |
HIP 116459 |
21.71 |
| 2026-05-14 00:00 |
23:37:15.02 |
+04:49:18.9 |
HIP 116459 |
23.88 |
| 2026-05-14 12:00 |
23:37:31.76 |
+04:51:27.5 |
HIP 116459 |
26.70 |
| 2026-05-15 00:00 |
23:37:48.41 |
+04:53:35.8 |
HIP 116459 |
29.97 |
| 2026-05-15 12:00 |
23:38:04.99 |
+04:55:43.7 |
HIP 116459 |
33.55 |
| 2026-05-16 00:00 |
23:38:21.48 |
+04:57:51.3 |
HIP 116799 |
30.55 |
| 2026-05-16 12:00 |
23:38:37.90 |
+04:59:58.6 |
HIP 116799 |
27.52 |
| 2026-05-17 00:00 |
23:38:54.23 |
+05:02:05.5 |
HIP 116799 |
24.99 |
| 2026-05-17 12:00 |
23:39:10.47 |
+05:04:12.1 |
HIP 116799 |
23.11 |
| 2026-05-18 00:00 |
23:39:26.63 |
+05:06:18.3 |
HIP 116799 |
22.03 |
| 2026-05-18 12:00 |
23:39:42.71 |
+05:08:24.1 |
HIP 116799 |
21.87 |
| 2026-05-19 00:00 |
23:39:58.69 |
+05:10:29.5 |
HIP 116862 |
19.79 |
| 2026-05-19 12:00 |
23:40:14.60 |
+05:12:34.6 |
HIP 116862 |
15.67 |
| 2026-05-20 00:00 |
23:40:30.41 |
+05:14:39.2 |
HIP 116862 |
11.83 |
| 2026-05-20 12:00 |
23:40:46.14 |
+05:16:43.5 |
HIP 116862 |
8.61 |
| 2026-05-21 00:00 |
23:41:01.77 |
+05:18:47.4 |
HIP 116862 |
6.92 |
| 2026-05-21 12:00 |
23:41:17.32 |
+05:20:50.9 |
HIP 116862 |
7.76 |
| 2026-05-22 00:00 |
23:41:32.78 |
+05:22:53.9 |
HIP 116862 |
10.52 |
| 2026-05-22 12:00 |
23:41:48.15 |
+05:24:56.6 |
HIP 116862 |
14.10 |
| 2026-05-23 00:00 |
23:42:03.42 |
+05:26:58.8 |
HIP 116862 |
17.99 |
| 2026-05-23 12:00 |
23:42:18.60 |
+05:29:00.6 |
HIP 116862 |
22.02 |
| 2026-05-24 00:00 |
23:42:33.70 |
+05:31:02.0 |
HIP 116862 |
26.11 |
| 2026-05-24 12:00 |
23:42:48.69 |
+05:33:02.9 |
HIP 116862 |
30.23 |
| 2026-05-25 00:00 |
23:43:03.60 |
+05:35:03.5 |
HIP 116862 |
34.35 |
| 2026-05-25 12:00 |
23:43:18.40 |
+05:37:03.5 |
HIP 117179 |
33.81 |
| 2026-05-26 00:00 |
23:43:33.12 |
+05:39:03.2 |
HIP 117179 |
29.68 |
| 2026-05-26 12:00 |
23:43:47.74 |
+05:41:02.3 |
HIP 117179 |
25.60 |
| 2026-05-27 00:00 |
23:44:02.26 |
+05:43:01.0 |
HIP 117179 |
21.57 |
| 2026-05-27 12:00 |
23:44:16.68 |
+05:44:59.3 |
HIP 117179 |
17.60 |
| 2026-05-28 00:00 |
23:44:31.01 |
+05:46:57.1 |
HIP 117179 |
13.73 |
| 2026-05-28 12:00 |
23:44:45.24 |
+05:48:54.4 |
HIP 117179 |
10.05 |
| 2026-05-29 00:00 |
23:44:59.37 |
+05:50:51.2 |
HIP 117179 |
6.82 |
| 2026-05-29 12:00 |
23:45:13.39 |
+05:52:47.6 |
HIP 117179 |
4.92 |
| 2026-05-30 00:00 |
23:45:27.32 |
+05:54:43.5 |
HIP 117179 |
5.81 |
| 2026-05-30 12:00 |
23:45:41.15 |
+05:56:38.9 |
HIP 117179 |
8.63 |
| 2026-05-31 00:00 |
23:45:54.88 |
+05:58:33.8 |
HIP 117179 |
12.07 |
| 2026-05-31 12:00 |
23:46:08.50 |
+06:00:28.1 |
HIP 117179 |
15.71 |
| 2026-06-01 00:00 |
23:46:22.02 |
+06:02:22.0 |
HIP 117179 |
19.42 |
| 2026-06-01 12:00 |
23:46:35.44 |
+06:04:15.4 |
HIP 117179 |
23.15 |
| 2026-06-02 00:00 |
23:46:48.75 |
+06:06:08.2 |
HIP 117179 |
26.89 |