| 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) |
| 2026-03-26 00:00 |
11:01:22.42 |
-28:13:49.8 |
HIP 53690 |
32.79 |
| 2026-03-26 12:00 |
11:01:12.70 |
-28:12:23.4 |
HIP 53690 |
31.52 |
| 2026-03-27 00:00 |
11:01:03.02 |
-28:10:56.3 |
HIP 53690 |
30.42 |
| 2026-03-27 12:00 |
11:00:53.40 |
-28:09:28.5 |
HIP 53690 |
29.53 |
| 2026-03-28 00:00 |
11:00:43.84 |
-28:08:00.1 |
HIP 53690 |
28.85 |
| 2026-03-28 12:00 |
11:00:34.33 |
-28:06:31.0 |
HIP 53690 |
28.41 |
| 2026-03-29 00:00 |
11:00:24.88 |
-28:05:01.3 |
HIP 53690 |
28.21 |
| 2026-03-29 12:00 |
11:00:15.48 |
-28:03:31.0 |
HIP 53690 |
28.26 |
| 2026-03-30 00:00 |
11:00:06.15 |
-28:02:00.0 |
HIP 53690 |
28.55 |
| 2026-03-30 12:00 |
10:59:56.87 |
-28:00:28.5 |
HIP 53690 |
29.08 |
| 2026-03-31 00:00 |
10:59:47.66 |
-27:58:56.4 |
HIP 53690 |
29.83 |
| 2026-03-31 12:00 |
10:59:38.51 |
-27:57:23.6 |
HIP 53724 |
28.47 |
| 2026-04-01 00:00 |
10:59:29.41 |
-27:55:50.4 |
HIP 53724 |
26.88 |
| 2026-04-01 12:00 |
10:59:20.39 |
-27:54:16.5 |
HIP 53724 |
25.43 |
| 2026-04-02 00:00 |
10:59:11.42 |
-27:52:42.1 |
HIP 53724 |
24.15 |
| 2026-04-02 12:00 |
10:59:02.53 |
-27:51:07.2 |
HIP 53724 |
23.06 |
| 2026-04-03 00:00 |
10:58:53.69 |
-27:49:31.7 |
HIP 53724 |
22.20 |
| 2026-04-03 12:00 |
10:58:44.93 |
-27:47:55.8 |
HIP 53724 |
21.58 |
| 2026-04-04 00:00 |
10:58:36.23 |
-27:46:19.3 |
HIP 53724 |
21.23 |
| 2026-04-04 12:00 |
10:58:27.61 |
-27:44:42.3 |
HIP 53724 |
21.16 |
| 2026-04-05 00:00 |
10:58:19.05 |
-27:43:04.8 |
HIP 53724 |
21.37 |
| 2026-04-05 12:00 |
10:58:10.56 |
-27:41:26.9 |
HIP 53724 |
21.84 |
| 2026-04-06 00:00 |
10:58:02.15 |
-27:39:48.5 |
HIP 53724 |
22.57 |
| 2026-04-06 12:00 |
10:57:53.80 |
-27:38:09.6 |
HIP 53724 |
23.52 |
| 2026-04-07 00:00 |
10:57:45.53 |
-27:36:30.3 |
HIP 53724 |
24.66 |
| 2026-04-07 12:00 |
10:57:37.34 |
-27:34:50.6 |
HIP 53724 |
25.97 |
| 2026-04-08 00:00 |
10:57:29.21 |
-27:33:10.5 |
HIP 53434 |
26.92 |
| 2026-04-08 12:00 |
10:57:21.17 |
-27:31:29.9 |
HIP 53434 |
26.60 |
| 2026-04-09 00:00 |
10:57:13.20 |
-27:29:49.0 |
HIP 53434 |
26.52 |
| 2026-04-09 12:00 |
10:57:05.31 |
-27:28:07.7 |
HIP 53434 |
26.67 |
| 2026-04-10 00:00 |
10:56:57.49 |
-27:26:26.0 |
HIP 53434 |
27.06 |
| 2026-04-10 12:00 |
10:56:49.76 |
-27:24:43.9 |
HIP 53434 |
27.67 |
| 2026-04-11 00:00 |
10:56:42.10 |
-27:23:01.5 |
HIP 53434 |
28.49 |
| 2026-04-11 12:00 |
10:56:34.53 |
-27:21:18.7 |
HIP 53412 |
26.96 |
| 2026-04-12 00:00 |
10:56:27.04 |
-27:19:35.6 |
HIP 53412 |
24.61 |
| 2026-04-12 12:00 |
10:56:19.62 |
-27:17:52.2 |
HIP 53412 |
22.28 |
| 2026-04-13 00:00 |
10:56:12.30 |
-27:16:08.5 |
HIP 53412 |
19.97 |
| 2026-04-13 12:00 |
10:56:05.05 |
-27:14:24.5 |
HIP 53412 |
17.68 |
| 2026-04-14 00:00 |
10:55:57.89 |
-27:12:40.3 |
HIP 53412 |
15.41 |
| 2026-04-14 12:00 |
10:55:50.82 |
-27:10:55.7 |
HIP 53412 |
13.18 |
| 2026-04-15 00:00 |
10:55:43.83 |
-27:09:10.9 |
HIP 53412 |
11.00 |
| 2026-04-15 12:00 |
10:55:36.92 |
-27:07:25.9 |
HIP 53412 |
8.91 |
| 2026-04-16 00:00 |
10:55:30.11 |
-27:05:40.6 |
HIP 53412 |
6.95 |