| Parameter |
Value |
| Designation |
P/2019 U4 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2019-09-18T08:38:38.333760Z |
| Orbit solution date (soln_date, UTC) |
2021-11-09T14:03:17Z |
| Obs used |
53 |
| NEO |
- |
| M1 |
18.600 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-10-25T12:45:41.212800Z |
| Discovery magnitude (MPC) |
21.11 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-10-19.0000000 |
| e |
0.47518301 |
| q (au) |
1.847129 |
| a (au) |
3.519568 |
| i (deg) |
11.692289 |
| Ω (om, deg) |
200.040609 |
| ω (w, deg) |
180.960217 |
| M (ma, deg) |
4.573581 |
Magnitude
Scatter + Global Linear
$$
M_a = (19.329 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
19.329 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.681 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
05:27:38.41 |
+17:12:28.2 |
HIP 25514 |
5.30 |
| 2026-07-29 12:00 |
05:28:45.68 |
+17:11:23.9 |
HIP 25583 |
10.93 |
| 2026-07-30 00:00 |
05:29:52.80 |
+17:10:17.6 |
HIP 25890 |
25.02 |
| 2026-07-30 12:00 |
05:30:59.76 |
+17:09:09.3 |
HIP 25890 |
9.08 |
| 2026-07-31 00:00 |
05:32:06.58 |
+17:07:58.9 |
HIP 25950 |
4.84 |
| 2026-07-31 12:00 |
05:33:13.24 |
+17:06:46.6 |
HIP 25950 |
14.50 |
| 2026-08-01 00:00 |
05:34:19.75 |
+17:05:32.2 |
HIP 26157 |
4.69 |
| 2026-08-01 12:00 |
05:35:26.10 |
+17:04:15.8 |
HIP 26157 |
12.86 |
| 2026-08-02 00:00 |
05:36:32.29 |
+17:02:57.4 |
HIP 26382 |
7.53 |
| 2026-08-02 12:00 |
05:37:38.33 |
+17:01:37.0 |
HIP 26382 |
8.32 |
| 2026-08-03 00:00 |
05:38:44.21 |
+17:00:14.7 |
HIP 26382 |
24.12 |
| 2026-08-03 12:00 |
05:39:49.93 |
+16:58:50.4 |
HIP 26734 |
19.01 |
| 2026-08-04 00:00 |
05:40:55.49 |
+16:57:24.1 |
HIP 26734 |
14.46 |
| 2026-08-04 12:00 |
05:42:00.89 |
+16:55:55.9 |
HIP 26734 |
23.49 |
| 2026-08-05 00:00 |
05:43:06.12 |
+16:54:25.8 |
HIP 26980 |
13.74 |
| 2026-08-05 12:00 |
05:44:11.19 |
+16:52:53.7 |
HIP 26980 |
14.82 |
| 2026-08-06 00:00 |
05:45:16.09 |
+16:51:19.7 |
HIP 26980 |
27.16 |
| 2026-08-06 12:00 |
05:46:20.83 |
+16:49:43.7 |
HIP 26980 |
41.71 |
| 2026-08-07 00:00 |
05:47:25.39 |
+16:48:05.9 |
HIP 27428 |
40.83 |
| 2026-08-07 12:00 |
05:48:29.79 |
+16:46:26.1 |
HIP 27567 |
28.55 |
| 2026-08-08 00:00 |
05:49:34.02 |
+16:44:44.5 |
HIP 27567 |
14.76 |
| 2026-08-08 12:00 |
05:50:38.07 |
+16:43:01.0 |
HIP 27567 |
9.95 |
| 2026-08-09 00:00 |
05:51:41.95 |
+16:41:15.7 |
HIP 27567 |
21.33 |
| 2026-08-09 12:00 |
05:52:45.65 |
+16:39:28.4 |
HIP 27805 |
19.16 |
| 2026-08-10 00:00 |
05:53:49.18 |
+16:37:39.4 |
HIP 27805 |
20.28 |
| 2026-08-10 12:00 |
05:54:52.53 |
+16:35:48.4 |
HIP 27805 |
30.37 |
| 2026-08-11 00:00 |
05:55:55.70 |
+16:33:55.7 |
HIP 28142 |
18.24 |
| 2026-08-11 12:00 |
05:56:58.69 |
+16:32:01.2 |
HIP 28142 |
10.89 |
| 2026-08-12 00:00 |
05:58:01.50 |
+16:30:04.8 |
HIP 28289 |
10.90 |
| 2026-08-12 12:00 |
05:59:04.12 |
+16:28:06.7 |
HIP 28289 |
9.67 |
| 2026-08-13 00:00 |
06:00:06.56 |
+16:26:06.7 |
HIP 28447 |
9.21 |
| 2026-08-13 12:00 |
06:01:08.81 |
+16:24:05.0 |
HIP 28447 |
12.32 |
| 2026-08-14 00:00 |
06:02:10.88 |
+16:22:01.6 |
HIP 28582 |
9.29 |
| 2026-08-14 12:00 |
06:03:12.76 |
+16:19:56.4 |
HIP 28582 |
20.63 |
| 2026-08-15 00:00 |
06:04:14.44 |
+16:17:49.5 |
HIP 28801 |
8.78 |
| 2026-08-15 12:00 |
06:05:15.94 |
+16:15:40.8 |
HIP 28801 |
7.85 |
| 2026-08-16 00:00 |
06:06:17.24 |
+16:13:30.4 |
HIP 28980 |
9.78 |
| 2026-08-16 12:00 |
06:07:18.35 |
+16:11:18.4 |
HIP 28980 |
5.37 |
| 2026-08-17 00:00 |
06:08:19.27 |
+16:09:04.6 |
HIP 28980 |
20.02 |
| 2026-08-17 12:00 |
06:09:19.99 |
+16:06:49.2 |
HIP 29274 |
18.22 |
| 2026-08-18 00:00 |
06:10:20.51 |
+16:04:32.2 |
HIP 29274 |
10.22 |
| 2026-08-18 12:00 |
06:11:20.84 |
+16:02:13.4 |
HIP 29434 |
11.63 |
| 2026-08-19 00:00 |
06:12:20.97 |
+15:59:53.1 |
HIP 29434 |
9.01 |