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) |
|---|---|---|---|---|
| 2026-06-01 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 |
| 2026-06-02 12:00 | 04:38:05.13 | -35:28:52.0 | HIP 21494 | 15.63 |
| 2026-06-03 00:00 | 04:38:15.16 | -35:28:32.3 | HIP 21494 | 17.55 |
| 2026-06-03 12:00 | 04:38:25.18 | -35:28:13.7 | HIP 21494 | 19.49 |
| 2026-06-04 00:00 | 04:38:35.19 | -35:27:56.3 | HIP 21724 | 18.83 |
| 2026-06-04 12:00 | 04:38:45.19 | -35:27:40.1 | HIP 21724 | 17.37 |
| 2026-06-05 00:00 | 04:38:55.19 | -35:27:25.1 | HIP 21724 | 16.02 |
| 2026-06-05 12:00 | 04:39:05.17 | -35:27:11.2 | HIP 21724 | 14.82 |
| 2026-06-06 00:00 | 04:39:15.15 | -35:26:58.4 | HIP 21724 | 13.80 |
| 2026-06-06 12:00 | 04:39:25.11 | -35:26:46.9 | HIP 21724 | 13.01 |
| 2026-06-07 00:00 | 04:39:35.06 | -35:26:36.5 | HIP 21724 | 12.48 |
| 2026-06-07 12:00 | 04:39:45.00 | -35:26:27.3 | HIP 21724 | 12.25 |
| 2026-06-08 00:00 | 04:39:54.93 | -35:26:19.2 | HIP 21724 | 12.34 |
| 2026-06-08 12:00 | 04:40:04.84 | -35:26:12.3 | HIP 21724 | 12.73 |
| 2026-06-09 00:00 | 04:40:14.73 | -35:26:06.6 | HIP 21724 | 13.40 |
| 2026-06-09 12:00 | 04:40:24.61 | -35:26:02.0 | HIP 21724 | 14.31 |
| 2026-06-10 00:00 | 04:40:34.48 | -35:25:58.6 | HIP 21724 | 15.40 |
| 2026-06-10 12:00 | 04:40:44.33 | -35:25:56.4 | HIP 21724 | 16.65 |
| 2026-06-11 00:00 | 04:40:54.16 | -35:25:55.3 | HIP 21872 | 15.45 |
| 2026-06-11 12:00 | 04:41:03.97 | -35:25:55.4 | HIP 21872 | 13.49 |
| 2026-06-12 00:00 | 04:41:13.76 | -35:25:56.6 | HIP 21872 | 11.54 |
| 2026-06-12 12:00 | 04:41:23.53 | -35:25:59.1 | HIP 21872 | 9.60 |
| 2026-06-13 00:00 | 04:41:33.28 | -35:26:02.7 | HIP 21872 | 7.68 |
| 2026-06-13 12:00 | 04:41:43.01 | -35:26:07.4 | HIP 21872 | 5.81 |
| 2026-06-14 00:00 | 04:41:52.72 | -35:26:13.4 | HIP 21872 | 4.05 |
| 2026-06-14 12:00 | 04:42:02.40 | -35:26:20.4 | HIP 21872 | 2.59 |
| 2026-06-15 00:00 | 04:42:12.06 | -35:26:28.7 | HIP 21872 | 2.19 |
| 2026-06-15 12:00 | 04:42:21.70 | -35:26:38.1 | HIP 21872 | 3.24 |
| 2026-06-16 00:00 | 04:42:31.30 | -35:26:48.7 | HIP 21872 | 4.88 |
| 2026-06-16 12:00 | 04:42:40.89 | -35:27:00.4 | HIP 21872 | 6.69 |
| 2026-06-17 00:00 | 04:42:50.44 | -35:27:13.3 | HIP 21872 | 8.56 |
| 2026-06-17 12:00 | 04:42:59.97 | -35:27:27.3 | HIP 21872 | 10.45 |
| 2026-06-18 00:00 | 04:43:09.46 | -35:27:42.5 | HIP 21872 | 12.36 |
| 2026-06-18 12:00 | 04:43:18.93 | -35:27:58.8 | HIP 21872 | 14.27 |
| 2026-06-19 00:00 | 04:43:28.37 | -35:28:16.3 | HIP 21872 | 16.18 |
| 2026-06-19 12:00 | 04:43:37.77 | -35:28:34.9 | HIP 21872 | 18.09 |
| 2026-06-20 00:00 | 04:43:47.14 | -35:28:54.7 | HIP 21872 | 20.00 |
| 2026-06-20 12:00 | 04:43:56.48 | -35:29:15.6 | HIP 21872 | 21.91 |
| 2026-06-21 00:00 | 04:44:05.79 | -35:29:37.7 | HIP 21872 | 23.81 |
| 2026-06-21 12:00 | 04:44:15.06 | -35:30:00.8 | HIP 21872 | 25.72 |
| 2026-06-22 00:00 | 04:44:24.30 | -35:30:25.1 | HIP 21872 | 27.62 |