| 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 · University of Arizona 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 |
0.999 |
| 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) |
| 2026-06-01 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 |
| 2026-06-02 12:00 |
10:52:07.73 |
-24:27:39.3 |
HIP 53276 |
23.83 |
| 2026-06-03 00:00 |
10:52:10.37 |
-24:26:18.7 |
HIP 53276 |
22.85 |
| 2026-06-03 12:00 |
10:52:13.11 |
-24:24:58.7 |
HIP 53276 |
21.91 |
| 2026-06-04 00:00 |
10:52:15.94 |
-24:23:39.4 |
HIP 53276 |
21.01 |
| 2026-06-04 12:00 |
10:52:18.86 |
-24:22:20.7 |
HIP 53276 |
20.16 |
| 2026-06-05 00:00 |
10:52:21.88 |
-24:21:02.5 |
HIP 53276 |
19.36 |
| 2026-06-05 12:00 |
10:52:24.99 |
-24:19:45.1 |
HIP 53276 |
18.62 |
| 2026-06-06 00:00 |
10:52:28.19 |
-24:18:28.2 |
HIP 53276 |
17.95 |
| 2026-06-06 12:00 |
10:52:31.49 |
-24:17:12.1 |
HIP 53276 |
17.36 |
| 2026-06-07 00:00 |
10:52:34.87 |
-24:15:56.5 |
HIP 53276 |
16.85 |
| 2026-06-07 12:00 |
10:52:38.35 |
-24:14:41.6 |
HIP 53276 |
16.44 |
| 2026-06-08 00:00 |
10:52:41.92 |
-24:13:27.4 |
HIP 53276 |
16.13 |
| 2026-06-08 12:00 |
10:52:45.58 |
-24:12:13.8 |
HIP 53276 |
15.92 |
| 2026-06-09 00:00 |
10:52:49.33 |
-24:11:00.9 |
HIP 53276 |
15.83 |
| 2026-06-09 12:00 |
10:52:53.17 |
-24:09:48.7 |
HIP 53276 |
15.86 |
| 2026-06-10 00:00 |
10:52:57.11 |
-24:08:37.2 |
HIP 53276 |
16.00 |
| 2026-06-10 12:00 |
10:53:01.13 |
-24:07:26.3 |
HIP 53276 |
16.25 |
| 2026-06-11 00:00 |
10:53:05.24 |
-24:06:16.1 |
HIP 53276 |
16.62 |
| 2026-06-11 12:00 |
10:53:09.44 |
-24:05:06.6 |
HIP 53276 |
17.09 |
| 2026-06-12 00:00 |
10:53:13.73 |
-24:03:57.8 |
HIP 53276 |
17.65 |
| 2026-06-12 12:00 |
10:53:18.11 |
-24:02:49.6 |
HIP 53276 |
18.30 |
| 2026-06-13 00:00 |
10:53:22.57 |
-24:01:42.2 |
HIP 53276 |
19.04 |
| 2026-06-13 12:00 |
10:53:27.12 |
-24:00:35.5 |
HIP 53276 |
19.85 |
| 2026-06-14 00:00 |
10:53:31.76 |
-23:59:29.5 |
HIP 53359 |
20.36 |
| 2026-06-14 12:00 |
10:53:36.49 |
-23:58:24.2 |
HIP 53359 |
20.18 |
| 2026-06-15 00:00 |
10:53:41.31 |
-23:57:19.6 |
HIP 53359 |
20.10 |
| 2026-06-15 12:00 |
10:53:46.21 |
-23:56:15.7 |
HIP 53359 |
20.12 |
| 2026-06-16 00:00 |
10:53:51.19 |
-23:55:12.5 |
HIP 53359 |
20.23 |
| 2026-06-16 12:00 |
10:53:56.26 |
-23:54:10.1 |
HIP 53359 |
20.44 |
| 2026-06-17 00:00 |
10:54:01.42 |
-23:53:08.4 |
HIP 53359 |
20.74 |
| 2026-06-17 12:00 |
10:54:06.66 |
-23:52:07.5 |
HIP 53359 |
21.14 |
| 2026-06-18 00:00 |
10:54:11.99 |
-23:51:07.2 |
HIP 53359 |
21.62 |
| 2026-06-18 12:00 |
10:54:17.39 |
-23:50:07.7 |
HIP 53359 |
22.19 |
| 2026-06-19 00:00 |
10:54:22.88 |
-23:49:09.0 |
HIP 53359 |
22.84 |
| 2026-06-19 12:00 |
10:54:28.46 |
-23:48:10.9 |
HIP 53359 |
23.56 |
| 2026-06-20 00:00 |
10:54:34.11 |
-23:47:13.6 |
HIP 53359 |
24.35 |
| 2026-06-20 12:00 |
10:54:39.85 |
-23:46:17.1 |
HIP 53359 |
25.21 |
| 2026-06-21 00:00 |
10:54:45.66 |
-23:45:21.3 |
HIP 53359 |
26.13 |
| 2026-06-21 12:00 |
10:54:51.56 |
-23:44:26.3 |
HIP 53359 |
27.10 |
| 2026-06-22 00:00 |
10:54:57.54 |
-23:43:32.0 |
HIP 53359 |
28.12 |