| Parameter |
Value |
| Designation |
P/2021 U1 (Wierzchos) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-09-30T23:25:09.215040Z |
| Orbit solution date (soln_date, UTC) |
2022-03-08T19:43:48Z |
| Obs used |
239 |
| NEO |
- |
| M1 |
16.000 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-10-18T08:26:24.028800Z |
| Discovery magnitude (MPC) |
19.17 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-11-26.0000000 |
| e |
0.71275870 |
| q (au) |
2.444983 |
| a (au) |
8.511949 |
| i (deg) |
30.560647 |
| Ω (om, deg) |
246.789455 |
| ω (w, deg) |
145.044255 |
| M (ma, deg) |
2.223495 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.832 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.832 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
1.000 |
| 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 |
10:51:46.97 |
-25:33:52.5 |
HIP 53095 |
3.30 |
| 2026-05-12 12:00 |
10:51:45.33 |
-25:32:10.8 |
HIP 53095 |
4.92 |
| 2026-05-13 00:00 |
10:51:43.79 |
-25:30:29.5 |
HIP 53095 |
6.60 |
| 2026-05-13 12:00 |
10:51:42.35 |
-25:28:48.5 |
HIP 53095 |
8.29 |
| 2026-05-14 00:00 |
10:51:41.02 |
-25:27:07.9 |
HIP 53095 |
9.98 |
| 2026-05-14 12:00 |
10:51:39.78 |
-25:25:27.6 |
HIP 53095 |
11.66 |
| 2026-05-15 00:00 |
10:51:38.65 |
-25:23:47.7 |
HIP 53095 |
13.34 |
| 2026-05-15 12:00 |
10:51:37.63 |
-25:22:08.1 |
HIP 53095 |
15.02 |
| 2026-05-16 00:00 |
10:51:36.70 |
-25:20:29.0 |
HIP 53010 |
16.52 |
| 2026-05-16 12:00 |
10:51:35.88 |
-25:18:50.2 |
HIP 53010 |
17.52 |
| 2026-05-17 00:00 |
10:51:35.16 |
-25:17:11.8 |
HIP 53010 |
18.62 |
| 2026-05-17 12:00 |
10:51:34.54 |
-25:15:33.9 |
HIP 53010 |
19.80 |
| 2026-05-18 00:00 |
10:51:34.03 |
-25:13:56.4 |
HIP 53010 |
21.06 |
| 2026-05-18 12:00 |
10:51:33.61 |
-25:12:19.3 |
HIP 53010 |
22.37 |
| 2026-05-19 00:00 |
10:51:33.30 |
-25:10:42.6 |
HIP 53010 |
23.72 |
| 2026-05-19 12:00 |
10:51:33.10 |
-25:09:06.4 |
HIP 53010 |
25.11 |
| 2026-05-20 00:00 |
10:51:32.99 |
-25:07:30.6 |
HIP 53010 |
26.52 |
| 2026-05-20 12:00 |
10:51:32.98 |
-25:05:55.3 |
HIP 53010 |
27.96 |
| 2026-05-21 00:00 |
10:51:33.08 |
-25:04:20.4 |
HIP 53010 |
29.41 |
| 2026-05-21 12:00 |
10:51:33.28 |
-25:02:46.1 |
HIP 53010 |
30.88 |
| 2026-05-22 00:00 |
10:51:33.58 |
-25:01:12.2 |
HIP 53010 |
32.36 |
| 2026-05-22 12:00 |
10:51:33.98 |
-24:59:38.8 |
HIP 53010 |
33.85 |
| 2026-05-23 00:00 |
10:51:34.48 |
-24:58:05.9 |
HIP 53010 |
35.34 |
| 2026-05-23 12:00 |
10:51:35.08 |
-24:56:33.4 |
HIP 53010 |
36.84 |
| 2026-05-24 00:00 |
10:51:35.78 |
-24:55:01.5 |
HIP 53010 |
38.34 |
| 2026-05-24 12:00 |
10:51:36.58 |
-24:53:30.2 |
HIP 53010 |
39.84 |
| 2026-05-25 00:00 |
10:51:37.48 |
-24:51:59.3 |
HIP 53010 |
41.35 |
| 2026-05-25 12:00 |
10:51:38.48 |
-24:50:28.9 |
HIP 53276 |
42.23 |
| 2026-05-26 00:00 |
10:51:39.58 |
-24:48:59.1 |
HIP 53276 |
40.99 |
| 2026-05-26 12:00 |
10:51:40.78 |
-24:47:29.9 |
HIP 53276 |
39.75 |
| 2026-05-27 00:00 |
10:51:42.07 |
-24:46:01.1 |
HIP 53276 |
38.53 |
| 2026-05-27 12:00 |
10:51:43.46 |
-24:44:32.9 |
HIP 53276 |
37.31 |
| 2026-05-28 00:00 |
10:51:44.96 |
-24:43:05.3 |
HIP 53276 |
36.11 |
| 2026-05-28 12:00 |
10:51:46.54 |
-24:41:38.2 |
HIP 53276 |
34.91 |
| 2026-05-29 00:00 |
10:51:48.23 |
-24:40:11.7 |
HIP 53276 |
33.73 |
| 2026-05-29 12:00 |
10:51:50.01 |
-24:38:45.8 |
HIP 53276 |
32.56 |
| 2026-05-30 00:00 |
10:51:51.89 |
-24:37:20.4 |
HIP 53276 |
31.40 |
| 2026-05-30 12:00 |
10:51:53.87 |
-24:35:55.6 |
HIP 53276 |
30.26 |
| 2026-05-31 00:00 |
10:51:55.94 |
-24:34:31.4 |
HIP 53276 |
29.13 |
| 2026-05-31 12:00 |
10:51:58.11 |
-24:33:07.8 |
HIP 53276 |
28.03 |
| 2026-06-01 00:00 |
10:52:00.37 |
-24:31:44.8 |
HIP 53276 |
26.94 |
| 2026-06-01 12:00 |
10:52:02.73 |
-24:30:22.4 |
HIP 53276 |
25.88 |
| 2026-06-02 00:00 |
10:52:05.18 |
-24:29:00.5 |
HIP 53276 |
24.84 |