| 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 |
0.999 |
| 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) |
| 2026-07-29 00:00 |
23:57:34.11 |
+08:17:08.6 |
HIP 117962 |
29.04 |
| 2026-07-29 12:00 |
23:57:30.82 |
+08:17:19.6 |
HIP 117962 |
28.26 |
| 2026-07-30 00:00 |
23:57:27.36 |
+08:17:29.4 |
HIP 117962 |
27.44 |
| 2026-07-30 12:00 |
23:57:23.74 |
+08:17:38.0 |
HIP 117962 |
26.57 |
| 2026-07-31 00:00 |
23:57:19.95 |
+08:17:45.3 |
HIP 117962 |
25.67 |
| 2026-07-31 12:00 |
23:57:15.99 |
+08:17:51.4 |
HIP 117962 |
24.72 |
| 2026-08-01 00:00 |
23:57:11.86 |
+08:17:56.2 |
HIP 117962 |
23.73 |
| 2026-08-01 12:00 |
23:57:07.57 |
+08:17:59.8 |
HIP 117962 |
22.70 |
| 2026-08-02 00:00 |
23:57:03.11 |
+08:18:02.1 |
HIP 117962 |
21.63 |
| 2026-08-02 12:00 |
23:56:58.48 |
+08:18:03.2 |
HIP 117962 |
20.52 |
| 2026-08-03 00:00 |
23:56:53.69 |
+08:18:03.0 |
HIP 117962 |
19.37 |
| 2026-08-03 12:00 |
23:56:48.73 |
+08:18:01.6 |
HIP 117962 |
18.17 |
| 2026-08-04 00:00 |
23:56:43.60 |
+08:17:58.8 |
HIP 117962 |
16.94 |
| 2026-08-04 12:00 |
23:56:38.31 |
+08:17:54.8 |
HIP 117962 |
15.66 |
| 2026-08-05 00:00 |
23:56:32.86 |
+08:17:49.6 |
HIP 117962 |
14.35 |
| 2026-08-05 12:00 |
23:56:27.23 |
+08:17:43.0 |
HIP 117962 |
12.99 |
| 2026-08-06 00:00 |
23:56:21.45 |
+08:17:35.1 |
HIP 117962 |
11.60 |
| 2026-08-06 12:00 |
23:56:15.50 |
+08:17:26.0 |
HIP 117962 |
10.18 |
| 2026-08-07 00:00 |
23:56:09.38 |
+08:17:15.5 |
HIP 117962 |
8.74 |
| 2026-08-07 12:00 |
23:56:03.10 |
+08:17:03.8 |
HIP 117962 |
7.27 |
| 2026-08-08 00:00 |
23:55:56.66 |
+08:16:50.8 |
HIP 117962 |
5.82 |
| 2026-08-08 12:00 |
23:55:50.05 |
+08:16:36.4 |
HIP 117962 |
4.43 |
| 2026-08-09 00:00 |
23:55:43.28 |
+08:16:20.7 |
HIP 117962 |
3.26 |
| 2026-08-09 12:00 |
23:55:36.35 |
+08:16:03.8 |
HIP 117962 |
2.69 |
| 2026-08-10 00:00 |
23:55:29.26 |
+08:15:45.5 |
HIP 117962 |
3.15 |
| 2026-08-10 12:00 |
23:55:22.01 |
+08:15:25.9 |
HIP 117962 |
4.38 |
| 2026-08-11 00:00 |
23:55:14.59 |
+08:15:05.0 |
HIP 117962 |
5.96 |
| 2026-08-11 12:00 |
23:55:07.02 |
+08:14:42.8 |
HIP 117962 |
7.70 |
| 2026-08-12 00:00 |
23:54:59.29 |
+08:14:19.2 |
HIP 117912 |
9.05 |
| 2026-08-12 12:00 |
23:54:51.41 |
+08:13:54.4 |
HIP 117912 |
9.70 |
| 2026-08-13 00:00 |
23:54:43.37 |
+08:13:28.2 |
HIP 117912 |
10.72 |
| 2026-08-13 12:00 |
23:54:35.17 |
+08:13:00.7 |
HIP 117912 |
12.05 |
| 2026-08-14 00:00 |
23:54:26.81 |
+08:12:31.9 |
HIP 117912 |
13.60 |
| 2026-08-14 12:00 |
23:54:18.31 |
+08:12:01.7 |
HIP 117912 |
15.33 |
| 2026-08-15 00:00 |
23:54:09.65 |
+08:11:30.3 |
HIP 117912 |
17.21 |
| 2026-08-15 12:00 |
23:54:00.84 |
+08:10:57.5 |
HIP 117912 |
19.20 |
| 2026-08-16 00:00 |
23:53:51.88 |
+08:10:23.5 |
HIP 117912 |
21.28 |
| 2026-08-16 12:00 |
23:53:42.78 |
+08:09:48.1 |
HIP 117912 |
23.44 |
| 2026-08-17 00:00 |
23:53:33.52 |
+08:09:11.4 |
HIP 117912 |
25.67 |
| 2026-08-17 12:00 |
23:53:24.12 |
+08:08:33.4 |
HIP 117912 |
27.97 |
| 2026-08-18 00:00 |
23:53:14.57 |
+08:07:54.1 |
HIP 117912 |
30.33 |
| 2026-08-18 12:00 |
23:53:04.88 |
+08:07:13.5 |
HIP 117912 |
32.75 |
| 2026-08-19 00:00 |
23:52:55.05 |
+08:06:31.6 |
HIP 117912 |
35.21 |