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) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 04:30:57.38 | -36:01:24.0 | HIP 21118 | 10.32 |
| 2026-05-12 12:00 | 04:31:07.02 | -36:00:14.1 | HIP 21118 | 8.11 |
| 2026-05-13 00:00 | 04:31:16.69 | -35:59:05.5 | HIP 21118 | 5.97 |
| 2026-05-13 12:00 | 04:31:26.37 | -35:57:57.9 | HIP 21118 | 3.98 |
| 2026-05-14 00:00 | 04:31:36.09 | -35:56:51.5 | HIP 21118 | 2.53 |
| 2026-05-14 12:00 | 04:31:45.82 | -35:55:46.3 | HIP 21118 | 2.68 |
| 2026-05-15 00:00 | 04:31:55.58 | -35:54:42.2 | HIP 21118 | 4.26 |
| 2026-05-15 12:00 | 04:32:05.37 | -35:53:39.3 | HIP 21118 | 6.27 |
| 2026-05-16 00:00 | 04:32:15.17 | -35:52:37.5 | HIP 21118 | 8.39 |
| 2026-05-16 12:00 | 04:32:24.99 | -35:51:36.9 | HIP 21118 | 10.57 |
| 2026-05-17 00:00 | 04:32:34.83 | -35:50:37.5 | HIP 21209 | 9.68 |
| 2026-05-17 12:00 | 04:32:44.70 | -35:49:39.2 | HIP 21209 | 7.99 |
| 2026-05-18 00:00 | 04:32:54.57 | -35:48:42.2 | HIP 21209 | 6.64 |
| 2026-05-18 12:00 | 04:33:04.47 | -35:47:46.2 | HIP 21209 | 5.88 |
| 2026-05-19 00:00 | 04:33:14.38 | -35:46:51.5 | HIP 21209 | 5.91 |
| 2026-05-19 12:00 | 04:33:24.31 | -35:45:57.9 | HIP 21209 | 6.73 |
| 2026-05-20 00:00 | 04:33:34.25 | -35:45:05.4 | HIP 21209 | 8.10 |
| 2026-05-20 12:00 | 04:33:44.20 | -35:44:14.2 | HIP 21209 | 9.78 |
| 2026-05-21 00:00 | 04:33:54.17 | -35:43:24.1 | HIP 21327 | 9.84 |
| 2026-05-21 12:00 | 04:34:04.14 | -35:42:35.2 | HIP 21327 | 7.66 |
| 2026-05-22 00:00 | 04:34:14.13 | -35:41:47.5 | HIP 21327 | 5.49 |
| 2026-05-22 12:00 | 04:34:24.13 | -35:41:00.9 | HIP 21327 | 3.32 |
| 2026-05-23 00:00 | 04:34:34.14 | -35:40:15.5 | HIP 21327 | 1.21 |
| 2026-05-23 12:00 | 04:34:44.16 | -35:39:31.3 | HIP 21327 | 1.14 |
| 2026-05-24 00:00 | 04:34:54.18 | -35:38:48.2 | HIP 21327 | 3.24 |
| 2026-05-24 12:00 | 04:35:04.21 | -35:38:06.3 | HIP 21355 | 3.99 |
| 2026-05-25 00:00 | 04:35:14.25 | -35:37:25.6 | HIP 21355 | 4.83 |
| 2026-05-25 12:00 | 04:35:24.29 | -35:36:46.1 | HIP 21355 | 6.33 |
| 2026-05-26 00:00 | 04:35:34.34 | -35:36:07.7 | HIP 21355 | 8.13 |
| 2026-05-26 12:00 | 04:35:44.39 | -35:35:30.5 | HIP 21355 | 10.07 |
| 2026-05-27 00:00 | 04:35:54.44 | -35:34:54.4 | HIP 21355 | 12.07 |
| 2026-05-27 12:00 | 04:36:04.50 | -35:34:19.5 | HIP 21494 | 11.64 |
| 2026-05-28 00:00 | 04:36:14.56 | -35:33:45.8 | HIP 21494 | 9.85 |
| 2026-05-28 12:00 | 04:36:24.62 | -35:33:13.3 | HIP 21494 | 8.21 |
| 2026-05-29 00:00 | 04:36:34.68 | -35:32:41.9 | HIP 21494 | 6.82 |
| 2026-05-29 12:00 | 04:36:44.74 | -35:32:11.7 | HIP 21494 | 5.86 |
| 2026-05-30 00:00 | 04:36:54.80 | -35:31:42.7 | HIP 21494 | 5.56 |
| 2026-05-30 12:00 | 04:37:04.86 | -35:31:14.8 | HIP 21494 | 6.00 |
| 2026-05-31 00:00 | 04:37:14.91 | -35:30:48.1 | HIP 21494 | 7.05 |
| 2026-05-31 12:00 | 04:37:24.96 | -35:30:22.5 | HIP 21494 | 8.48 |
| 2026-06-01 00:00 | 04:37:35.01 | -35:29:58.1 | HIP 21494 | 10.12 |
| 2026-06-01 12:00 | 04:37:45.06 | -35:29:34.9 | HIP 21494 | 11.89 |
| 2026-06-02 00:00 | 04:37:55.10 | -35:29:12.9 | HIP 21494 | 13.74 |