C/2019 U5 (PANSTARRS)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2019 U5 (PANSTARRS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2023-03-29T21:49:38.544960Z |
| Orbit solution date (soln_date, UTC) | 2026-03-11T21:13:03Z |
| Obs used | 5421 |
| NEO | - |
| M1 | 8.200 |
| K1 | 5.750 |
| PC | - |
| Discovery observation (MPC, UTC) | 2019-10-22T05:17:08.131200Z |
| Discovery magnitude (MPC) | 21.16 w |
| Discovery observatory (MPC) | F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2022-09-27.0000000 |
| e | 1.00143151 |
| q (au) | 3.624067 |
| a (au) | -2531.636497 |
| i (deg) | 113.521207 |
| Ω (om, deg) | 2.637190 |
| ω (w, deg) | 181.508925 |
| M (ma, deg) | -0.001423 |
Magnitude
Scatter + Global Linear
$$ M_a = (7.172 + 2.222\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 7.172 |
| n | 2.222 |
| gf | 1.000 |
| gb | -0.999 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) | End (UTC) | a | b |
|---|---|---|---|
| 2019-10-11 | 2022-03-07 | +5.0078 | -3.922 |
| 2022-03-07 | 2023-03-29 | +0.7892 | -0.684 |
| 2023-03-29 | 2024-06-07 | -3.7459 | +2.172 |
| 2024-06-07 | 2026-01-09 | +1.0412 | -1.120 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Finding Chart
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 04:19:44.29 | -39:09:32.2 | HIP 20061 | 31.21 |
| 2026-03-26 12:00 | 04:19:47.75 | -39:06:48.9 | HIP 20061 | 33.81 |
| 2026-03-27 00:00 | 04:19:51.32 | -39:04:06.3 | HIP 19989 | 33.28 |
| 2026-03-27 12:00 | 04:19:54.99 | -39:01:24.4 | HIP 19989 | 32.97 |
| 2026-03-28 00:00 | 04:19:58.77 | -38:58:43.4 | HIP 19989 | 32.92 |
| 2026-03-28 12:00 | 04:20:02.66 | -38:56:03.1 | HIP 19989 | 33.12 |
| 2026-03-29 00:00 | 04:20:06.64 | -38:53:23.7 | HIP 19989 | 33.58 |
| 2026-03-29 12:00 | 04:20:10.73 | -38:50:45.0 | HIP 19989 | 34.27 |
| 2026-03-30 00:00 | 04:20:14.93 | -38:48:07.1 | HIP 20048 | 34.82 |
| 2026-03-30 12:00 | 04:20:19.22 | -38:45:30.0 | HIP 20048 | 33.89 |
| 2026-03-31 00:00 | 04:20:23.61 | -38:42:53.8 | HIP 20048 | 33.17 |
| 2026-03-31 12:00 | 04:20:28.10 | -38:40:18.3 | HIP 20048 | 32.70 |
| 2026-04-01 00:00 | 04:20:32.69 | -38:37:43.7 | HIP 20048 | 32.48 |
| 2026-04-01 12:00 | 04:20:37.38 | -38:35:10.0 | HIP 20048 | 32.51 |
| 2026-04-02 00:00 | 04:20:42.16 | -38:32:37.0 | HIP 20048 | 32.78 |
| 2026-04-02 12:00 | 04:20:47.03 | -38:30:04.9 | HIP 20048 | 33.30 |
| 2026-04-03 00:00 | 04:20:52.01 | -38:27:33.7 | HIP 20048 | 34.05 |
| 2026-04-03 12:00 | 04:20:57.07 | -38:25:03.3 | HIP 20077 | 34.23 |
| 2026-04-04 00:00 | 04:21:02.23 | -38:22:33.8 | HIP 20077 | 34.24 |
| 2026-04-04 12:00 | 04:21:07.48 | -38:20:05.1 | HIP 20372 | 34.02 |
| 2026-04-05 00:00 | 04:21:12.82 | -38:17:37.4 | HIP 20372 | 31.39 |
| 2026-04-05 12:00 | 04:21:18.24 | -38:15:10.5 | HIP 20372 | 28.78 |
| 2026-04-06 00:00 | 04:21:23.76 | -38:12:44.4 | HIP 20372 | 26.19 |
| 2026-04-06 12:00 | 04:21:29.37 | -38:10:19.3 | HIP 20372 | 23.64 |
| 2026-04-07 00:00 | 04:21:35.06 | -38:07:55.1 | HIP 20372 | 21.12 |
| 2026-04-07 12:00 | 04:21:40.84 | -38:05:31.7 | HIP 20372 | 18.65 |
| 2026-04-08 00:00 | 04:21:46.71 | -38:03:09.3 | HIP 20372 | 16.25 |
| 2026-04-08 12:00 | 04:21:52.66 | -38:00:47.8 | HIP 20372 | 13.96 |
| 2026-04-09 00:00 | 04:21:58.69 | -37:58:27.2 | HIP 20372 | 11.83 |
| 2026-04-09 12:00 | 04:22:04.81 | -37:56:07.5 | HIP 20372 | 9.96 |
| 2026-04-10 00:00 | 04:22:11.01 | -37:53:48.7 | HIP 20372 | 8.53 |
| 2026-04-10 12:00 | 04:22:17.29 | -37:51:30.9 | HIP 20372 | 7.76 |
| 2026-04-11 00:00 | 04:22:23.65 | -37:49:14.0 | HIP 20372 | 7.86 |
| 2026-04-11 12:00 | 04:22:30.09 | -37:46:58.1 | HIP 20372 | 8.78 |
| 2026-04-12 00:00 | 04:22:36.61 | -37:44:43.1 | HIP 20372 | 10.30 |
| 2026-04-12 12:00 | 04:22:43.21 | -37:42:29.1 | HIP 20372 | 12.20 |
| 2026-04-13 00:00 | 04:22:49.88 | -37:40:16.0 | HIP 20372 | 14.33 |
| 2026-04-13 12:00 | 04:22:56.63 | -37:38:03.9 | HIP 20372 | 16.59 |
| 2026-04-14 00:00 | 04:23:03.45 | -37:35:52.8 | HIP 20372 | 18.93 |
| 2026-04-14 12:00 | 04:23:10.35 | -37:33:42.6 | HIP 20593 | 17.81 |
| 2026-04-15 00:00 | 04:23:17.32 | -37:31:33.4 | HIP 20454 | 16.35 |
| 2026-04-15 12:00 | 04:23:24.37 | -37:29:25.3 | HIP 20454 | 14.80 |
| 2026-04-16 00:00 | 04:23:31.48 | -37:27:18.1 | HIP 20454 | 13.57 |