C/2016 Q2 (PANSTARRS)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2016 Q2 (PANSTARRS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2021-05-11T15:07:39.907200Z |
| Orbit solution date (soln_date, UTC) | 2024-04-20T20:42:17Z |
| Obs used | 662 |
| NEO | - |
| M1 | 10.800 |
| K1 | 4.500 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2020-08-26.0000000 |
| e | 0.99986869 |
| q (au) | 7.082106 |
| a (au) | 53935.651327 |
| i (deg) | 109.388884 |
| Ω (om, deg) | 322.298041 |
| ω (w, deg) | 84.508570 |
| M (ma, deg) | 359.999980 |
Magnitude
Scatter + Global Linear
$$ M_a = (9.586 + 4.868\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 9.586 |
| n | 4.868 |
| gf | 1.000 |
| gb | -0.925 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) | End (UTC) | a | b |
|---|---|---|---|
| 2016-08-26 | 2017-08-25 | -21.8320 | +23.366 |
| 2017-08-25 | 2018-08-14 | -2.5298 | +3.124 |
| 2018-08-14 | 2019-08-10 | +29.5957 | -28.173 |
| 2019-08-10 | 2021-05-07 | -11.4200 | +9.723 |
| 2021-05-13 | 2024-04-12 | +5.4378 | -4.459 |
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 | 09:48:12.49 | +23:34:40.9 | HIP 48023 | 12.25 |
| 2026-05-12 12:00 | 09:48:10.21 | +23:33:48.7 | HIP 48023 | 12.10 |
| 2026-05-13 00:00 | 09:48:08.00 | +23:32:56.2 | HIP 48023 | 12.05 |
| 2026-05-13 12:00 | 09:48:05.88 | +23:32:03.4 | HIP 48023 | 12.10 |
| 2026-05-14 00:00 | 09:48:03.84 | +23:31:10.3 | HIP 48023 | 12.25 |
| 2026-05-14 12:00 | 09:48:01.89 | +23:30:16.9 | HIP 48023 | 12.50 |
| 2026-05-15 00:00 | 09:48:00.01 | +23:29:23.2 | HIP 48023 | 12.84 |
| 2026-05-15 12:00 | 09:47:58.22 | +23:28:29.2 | HIP 48023 | 13.26 |
| 2026-05-16 00:00 | 09:47:56.51 | +23:27:35.0 | HIP 48023 | 13.75 |
| 2026-05-16 12:00 | 09:47:54.88 | +23:26:40.4 | HIP 48023 | 14.31 |
| 2026-05-17 00:00 | 09:47:53.33 | +23:25:45.5 | HIP 48023 | 14.92 |
| 2026-05-17 12:00 | 09:47:51.87 | +23:24:50.4 | HIP 48023 | 15.58 |
| 2026-05-18 00:00 | 09:47:50.48 | +23:23:55.0 | HIP 48023 | 16.29 |
| 2026-05-18 12:00 | 09:47:49.17 | +23:22:59.3 | HIP 48023 | 17.03 |
| 2026-05-19 00:00 | 09:47:47.95 | +23:22:03.4 | HIP 48023 | 17.81 |
| 2026-05-19 12:00 | 09:47:46.80 | +23:21:07.1 | HIP 48023 | 18.62 |
| 2026-05-20 00:00 | 09:47:45.74 | +23:20:10.6 | HIP 48023 | 19.45 |
| 2026-05-20 12:00 | 09:47:44.75 | +23:19:13.9 | HIP 48023 | 20.30 |
| 2026-05-21 00:00 | 09:47:43.84 | +23:18:16.8 | HIP 48023 | 21.17 |
| 2026-05-21 12:00 | 09:47:43.02 | +23:17:19.5 | HIP 48023 | 22.06 |
| 2026-05-22 00:00 | 09:47:42.26 | +23:16:22.0 | HIP 48023 | 22.96 |
| 2026-05-22 12:00 | 09:47:41.59 | +23:15:24.2 | HIP 48023 | 23.88 |
| 2026-05-23 00:00 | 09:47:41.00 | +23:14:26.1 | HIP 48023 | 24.80 |
| 2026-05-23 12:00 | 09:47:40.48 | +23:13:27.8 | HIP 48023 | 25.74 |
| 2026-05-24 00:00 | 09:47:40.04 | +23:12:29.3 | HIP 48023 | 26.69 |
| 2026-05-24 12:00 | 09:47:39.67 | +23:11:30.5 | HIP 48023 | 27.65 |
| 2026-05-25 00:00 | 09:47:39.38 | +23:10:31.5 | HIP 48023 | 28.61 |
| 2026-05-25 12:00 | 09:47:39.17 | +23:09:32.2 | HIP 48023 | 29.58 |
| 2026-05-26 00:00 | 09:47:39.03 | +23:08:32.7 | HIP 48023 | 30.56 |
| 2026-05-26 12:00 | 09:47:38.97 | +23:07:33.0 | HIP 48023 | 31.55 |
| 2026-05-27 00:00 | 09:47:38.98 | +23:06:33.0 | HIP 48023 | 32.54 |
| 2026-05-27 12:00 | 09:47:39.07 | +23:05:32.8 | HIP 48023 | 33.54 |
| 2026-05-28 00:00 | 09:47:39.23 | +23:04:32.4 | HIP 48144 | 32.69 |
| 2026-05-28 12:00 | 09:47:39.46 | +23:03:31.8 | HIP 48144 | 31.80 |
| 2026-05-29 00:00 | 09:47:39.77 | +23:02:30.9 | HIP 48144 | 30.91 |
| 2026-05-29 12:00 | 09:47:40.15 | +23:01:29.8 | HIP 48144 | 30.01 |
| 2026-05-30 00:00 | 09:47:40.60 | +23:00:28.6 | HIP 48144 | 29.11 |
| 2026-05-30 12:00 | 09:47:41.12 | +22:59:27.1 | HIP 48144 | 28.20 |
| 2026-05-31 00:00 | 09:47:41.72 | +22:58:25.4 | HIP 48144 | 27.29 |
| 2026-05-31 12:00 | 09:47:42.39 | +22:57:23.4 | HIP 48144 | 26.38 |
| 2026-06-01 00:00 | 09:47:43.13 | +22:56:21.3 | HIP 48144 | 25.46 |
| 2026-06-01 12:00 | 09:47:43.94 | +22:55:19.0 | HIP 48144 | 24.54 |
| 2026-06-02 00:00 | 09:47:44.82 | +22:54:16.5 | HIP 48144 | 23.62 |