P/2019 U4 (PANSTARRS)
| 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) |
| 2026-02-03 00:00 |
22:14:24.39 |
-05:41:50.6 |
HIP 109783 |
3.88 |
| 2026-02-03 12:00 |
22:15:33.61 |
-05:37:00.0 |
HIP 109874 |
5.62 |
| 2026-02-04 00:00 |
22:16:42.89 |
-05:32:08.0 |
HIP 110023 |
10.67 |
| 2026-02-04 12:00 |
22:17:52.22 |
-05:27:14.7 |
HIP 110023 |
12.06 |
| 2026-02-05 00:00 |
22:19:01.61 |
-05:22:20.0 |
HIP 110134 |
12.46 |
| 2026-02-05 12:00 |
22:20:11.05 |
-05:17:24.0 |
HIP 110359 |
17.35 |
| 2026-02-06 00:00 |
22:21:20.55 |
-05:12:26.6 |
HIP 110359 |
6.42 |
| 2026-02-06 12:00 |
22:22:30.10 |
-05:07:27.9 |
HIP 110359 |
20.74 |
| 2026-02-07 00:00 |
22:23:39.71 |
-05:02:27.9 |
HIP 110578 |
13.99 |
| 2026-02-07 12:00 |
22:24:49.37 |
-04:57:26.7 |
HIP 110578 |
12.82 |
| 2026-02-08 00:00 |
22:25:59.09 |
-04:52:24.1 |
HIP 110739 |
18.37 |
| 2026-02-08 12:00 |
22:27:08.86 |
-04:47:20.3 |
HIP 110920 |
17.82 |
| 2026-02-09 00:00 |
22:28:18.68 |
-04:42:15.1 |
HIP 110920 |
7.84 |
| 2026-02-09 12:00 |
22:29:28.56 |
-04:37:08.8 |
HIP 111102 |
18.93 |
| 2026-02-10 00:00 |
22:30:38.49 |
-04:32:01.2 |
HIP 111102 |
17.19 |
| 2026-02-10 12:00 |
22:31:48.48 |
-04:26:52.3 |
HIP 111238 |
23.88 |
| 2026-02-11 00:00 |
22:32:58.51 |
-04:21:42.3 |
HIP 111373 |
13.65 |
| 2026-02-11 12:00 |
22:34:08.60 |
-04:16:31.0 |
HIP 111373 |
12.60 |
| 2026-02-12 00:00 |
22:35:18.74 |
-04:11:18.6 |
HIP 111484 |
14.49 |
| 2026-02-12 12:00 |
22:36:28.94 |
-04:06:04.9 |
HIP 111710 |
20.52 |
| 2026-02-13 00:00 |
22:37:39.18 |
-04:00:50.1 |
HIP 111710 |
12.92 |
| 2026-02-13 12:00 |
22:38:49.48 |
-03:55:34.1 |
HIP 111840 |
20.20 |
| 2026-02-14 00:00 |
22:39:59.82 |
-03:50:17.0 |
HIP 111840 |
17.70 |
| 2026-02-14 12:00 |
22:41:10.22 |
-03:44:58.8 |
HIP 111965 |
12.98 |
| 2026-02-15 00:00 |
22:42:20.67 |
-03:39:39.5 |
HIP 112079 |
11.79 |
| 2026-02-15 12:00 |
22:43:31.16 |
-03:34:19.0 |
HIP 112079 |
21.92 |
| 2026-02-16 00:00 |
22:44:41.71 |
-03:28:57.5 |
HIP 112271 |
24.32 |
| 2026-02-16 12:00 |
22:45:52.31 |
-03:23:34.8 |
HIP 112271 |
28.02 |
| 2026-02-17 00:00 |
22:47:02.95 |
-03:18:11.2 |
HIP 112662 |
28.85 |
| 2026-02-17 12:00 |
22:48:13.64 |
-03:12:46.4 |
HIP 112662 |
13.45 |
| 2026-02-18 00:00 |
22:49:24.38 |
-03:07:20.7 |
HIP 112662 |
14.53 |
| 2026-02-18 12:00 |
22:50:35.17 |
-03:01:53.9 |
HIP 112742 |
15.92 |
| 2026-02-19 00:00 |
22:51:46.01 |
-02:56:26.1 |
HIP 112866 |
18.58 |
| 2026-02-19 12:00 |
22:52:56.89 |
-02:50:57.4 |
HIP 112967 |
14.05 |
| 2026-02-20 00:00 |
22:54:07.82 |
-02:45:27.7 |
HIP 113101 |
6.40 |
| 2026-02-20 12:00 |
22:55:18.79 |
-02:39:57.0 |
HIP 113101 |
19.21 |
| 2026-02-21 00:00 |
22:56:29.81 |
-02:34:25.4 |
HIP 113421 |
28.49 |
| 2026-02-21 12:00 |
22:57:40.88 |
-02:28:52.8 |
HIP 113421 |
10.08 |
| 2026-02-22 00:00 |
22:58:51.99 |
-02:23:19.4 |
HIP 113421 |
9.11 |
| 2026-02-22 12:00 |
23:00:03.15 |
-02:17:45.0 |
HIP 113547 |
9.30 |
| 2026-02-23 00:00 |
23:01:14.35 |
-02:12:09.8 |
HIP 113547 |
25.54 |
| 2026-02-23 12:00 |
23:02:25.59 |
-02:06:33.7 |
HIP 113931 |
30.88 |
| 2026-02-24 00:00 |
23:03:36.88 |
-02:00:56.8 |
HIP 113931 |
12.50 |