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
$$ M_a = (7.169 + 2.224\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 7.169 |
| n | 2.224 |
| gf | 0.999 |
| gb | -0.502 |
| 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 | +5.0029 | -3.919 |
| 2022-03-07 | 2023-03-29 | +0.7843 | -0.681 |
| 2023-03-29 | 2024-06-07 | -3.7649 | +2.184 |
| 2024-06-07 | 2026-02-13 | +1.1231 | -1.186 |
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) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 04:51:25.25 | -40:38:32.8 | HIP 22579 | 13.77 |
| 2026-09-20 12:00 | 04:51:17.39 | -40:40:53.1 | HIP 22579 | 16.29 |
| 2026-09-21 00:00 | 04:51:09.40 | -40:43:13.3 | HIP 22579 | 18.89 |
| 2026-09-21 12:00 | 04:51:01.26 | -40:45:33.1 | HIP 22506 | 17.98 |
| 2026-09-22 00:00 | 04:50:52.99 | -40:47:52.7 | HIP 22506 | 15.34 |
| 2026-09-22 12:00 | 04:50:44.59 | -40:50:12.0 | HIP 22506 | 12.78 |
| 2026-09-23 00:00 | 04:50:36.05 | -40:52:31.0 | HIP 22506 | 10.34 |
| 2026-09-23 12:00 | 04:50:27.38 | -40:54:49.8 | HIP 22506 | 8.17 |
| 2026-09-24 00:00 | 04:50:18.57 | -40:57:08.1 | HIP 22506 | 6.55 |
| 2026-09-24 12:00 | 04:50:09.62 | -40:59:26.2 | HIP 22506 | 5.95 |
| 2026-09-25 00:00 | 04:50:00.54 | -41:01:43.9 | HIP 22506 | 6.67 |
| 2026-09-25 12:00 | 04:49:51.33 | -41:04:01.2 | HIP 22506 | 8.39 |
| 2026-09-26 00:00 | 04:49:41.98 | -41:06:18.2 | HIP 22506 | 10.64 |
| 2026-09-26 12:00 | 04:49:32.50 | -41:08:34.8 | HIP 22506 | 13.16 |
| 2026-09-27 00:00 | 04:49:22.88 | -41:10:51.0 | HIP 22488 | 13.08 |
| 2026-09-27 12:00 | 04:49:13.13 | -41:13:06.8 | HIP 22488 | 13.35 |
| 2026-09-28 00:00 | 04:49:03.24 | -41:15:22.1 | HIP 22377 | 12.60 |
| 2026-09-28 12:00 | 04:48:53.22 | -41:17:37.0 | HIP 22377 | 10.49 |
| 2026-09-29 00:00 | 04:48:43.07 | -41:19:51.5 | HIP 22377 | 8.88 |
| 2026-09-29 12:00 | 04:48:32.78 | -41:22:05.4 | HIP 22377 | 8.08 |
| 2026-09-30 00:00 | 04:48:22.36 | -41:24:19.0 | HIP 22377 | 8.34 |
| 2026-09-30 12:00 | 04:48:11.81 | -41:26:32.0 | HIP 22377 | 9.58 |
| 2026-10-01 00:00 | 04:48:01.12 | -41:28:44.5 | HIP 22377 | 11.50 |
| 2026-10-01 12:00 | 04:47:50.30 | -41:30:56.5 | HIP 22377 | 13.82 |
| 2026-10-02 00:00 | 04:47:39.35 | -41:33:07.9 | HIP 22377 | 16.38 |
| 2026-10-02 12:00 | 04:47:28.27 | -41:35:18.8 | HIP 22377 | 19.08 |
| 2026-10-03 00:00 | 04:47:17.06 | -41:37:29.2 | HIP 22286 | 17.92 |
| 2026-10-03 12:00 | 04:47:05.71 | -41:39:38.9 | HIP 22286 | 17.16 |
| 2026-10-04 00:00 | 04:46:54.24 | -41:41:48.1 | HIP 22286 | 16.95 |
| 2026-10-04 12:00 | 04:46:42.63 | -41:43:56.7 | HIP 22286 | 17.29 |
| 2026-10-05 00:00 | 04:46:30.89 | -41:46:04.6 | HIP 22103 | 17.16 |
| 2026-10-05 12:00 | 04:46:19.02 | -41:48:11.9 | HIP 22103 | 14.09 |
| 2026-10-06 00:00 | 04:46:07.03 | -41:50:18.6 | HIP 22103 | 11.02 |
| 2026-10-06 12:00 | 04:45:54.90 | -41:52:24.6 | HIP 22103 | 7.93 |
| 2026-10-07 00:00 | 04:45:42.64 | -41:54:29.9 | HIP 22103 | 4.84 |
| 2026-10-07 12:00 | 04:45:30.26 | -41:56:34.5 | HIP 22103 | 1.74 |
| 2026-10-08 00:00 | 04:45:17.75 | -41:58:38.4 | HIP 22103 | 1.37 |
| 2026-10-08 12:00 | 04:45:05.11 | -42:00:41.6 | HIP 22103 | 4.49 |
| 2026-10-09 00:00 | 04:44:52.35 | -42:02:44.0 | HIP 22103 | 7.62 |
| 2026-10-09 12:00 | 04:44:39.46 | -42:04:45.7 | HIP 22103 | 10.75 |
| 2026-10-10 00:00 | 04:44:26.44 | -42:06:46.6 | HIP 22103 | 13.90 |
| 2026-10-10 12:00 | 04:44:13.30 | -42:08:46.7 | HIP 22103 | 17.05 |
| 2026-10-11 00:00 | 04:44:00.04 | -42:10:46.0 | HIP 22103 | 20.21 |