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) |
|---|---|---|---|---|
| 2026-03-26 00:00 | 09:58:01.34 | +24:28:03.9 | HIP 48810 | 21.74 |
| 2026-03-26 12:00 | 09:57:51.41 | +24:27:50.6 | HIP 48810 | 21.09 |
| 2026-03-27 00:00 | 09:57:41.55 | +24:27:36.8 | HIP 48810 | 20.67 |
| 2026-03-27 12:00 | 09:57:31.76 | +24:27:22.5 | HIP 48810 | 20.50 |
| 2026-03-28 00:00 | 09:57:22.04 | +24:27:07.6 | HIP 48810 | 20.59 |
| 2026-03-28 12:00 | 09:57:12.39 | +24:26:52.4 | HIP 48810 | 20.92 |
| 2026-03-29 00:00 | 09:57:02.80 | +24:26:36.6 | HIP 48810 | 21.47 |
| 2026-03-29 12:00 | 09:56:53.29 | +24:26:20.3 | HIP 48810 | 22.24 |
| 2026-03-30 00:00 | 09:56:43.85 | +24:26:03.5 | HIP 48810 | 23.18 |
| 2026-03-30 12:00 | 09:56:34.48 | +24:25:46.3 | HIP 48642 | 23.69 |
| 2026-03-31 00:00 | 09:56:25.18 | +24:25:28.6 | HIP 48642 | 22.09 |
| 2026-03-31 12:00 | 09:56:15.95 | +24:25:10.4 | HIP 48642 | 20.61 |
| 2026-04-01 00:00 | 09:56:06.80 | +24:24:51.7 | HIP 48642 | 19.26 |
| 2026-04-01 12:00 | 09:55:57.71 | +24:24:32.5 | HIP 48642 | 18.07 |
| 2026-04-02 00:00 | 09:55:48.71 | +24:24:12.9 | HIP 48642 | 17.08 |
| 2026-04-02 12:00 | 09:55:39.77 | +24:23:52.7 | HIP 48642 | 16.30 |
| 2026-04-03 00:00 | 09:55:30.91 | +24:23:32.1 | HIP 48642 | 15.77 |
| 2026-04-03 12:00 | 09:55:22.13 | +24:23:11.1 | HIP 48642 | 15.51 |
| 2026-04-04 00:00 | 09:55:13.42 | +24:22:49.5 | HIP 48642 | 15.52 |
| 2026-04-04 12:00 | 09:55:04.78 | +24:22:27.5 | HIP 48642 | 15.79 |
| 2026-04-05 00:00 | 09:54:56.23 | +24:22:05.0 | HIP 48642 | 16.32 |
| 2026-04-05 12:00 | 09:54:47.75 | +24:21:42.0 | HIP 48642 | 17.06 |
| 2026-04-06 00:00 | 09:54:39.34 | +24:21:18.6 | HIP 48642 | 17.99 |
| 2026-04-06 12:00 | 09:54:31.02 | +24:20:54.7 | HIP 48642 | 19.07 |
| 2026-04-07 00:00 | 09:54:22.77 | +24:20:30.3 | HIP 48642 | 20.28 |
| 2026-04-07 12:00 | 09:54:14.60 | +24:20:05.5 | HIP 48642 | 21.59 |
| 2026-04-08 00:00 | 09:54:06.50 | +24:19:40.2 | HIP 48642 | 22.98 |
| 2026-04-08 12:00 | 09:53:58.49 | +24:19:14.5 | HIP 48642 | 24.43 |
| 2026-04-09 00:00 | 09:53:50.56 | +24:18:48.3 | HIP 48642 | 25.93 |
| 2026-04-09 12:00 | 09:53:42.70 | +24:18:21.6 | HIP 48390 | 25.55 |
| 2026-04-10 00:00 | 09:53:34.93 | +24:17:54.5 | HIP 48390 | 23.93 |
| 2026-04-10 12:00 | 09:53:27.24 | +24:17:26.9 | HIP 48390 | 22.36 |
| 2026-04-11 00:00 | 09:53:19.62 | +24:16:58.8 | HIP 48390 | 20.85 |
| 2026-04-11 12:00 | 09:53:12.09 | +24:16:30.3 | HIP 48390 | 19.41 |
| 2026-04-12 00:00 | 09:53:04.64 | +24:16:01.4 | HIP 48390 | 18.05 |
| 2026-04-12 12:00 | 09:52:57.27 | +24:15:32.0 | HIP 48390 | 16.78 |
| 2026-04-13 00:00 | 09:52:49.99 | +24:15:02.2 | HIP 48390 | 15.63 |
| 2026-04-13 12:00 | 09:52:42.78 | +24:14:31.9 | HIP 48390 | 14.61 |
| 2026-04-14 00:00 | 09:52:35.66 | +24:14:01.2 | HIP 48390 | 13.75 |
| 2026-04-14 12:00 | 09:52:28.62 | +24:13:30.0 | HIP 48390 | 13.07 |
| 2026-04-15 00:00 | 09:52:21.67 | +24:12:58.4 | HIP 48390 | 12.60 |
| 2026-04-15 12:00 | 09:52:14.79 | +24:12:26.3 | HIP 48390 | 12.35 |
| 2026-04-16 00:00 | 09:52:08.01 | +24:11:53.8 | HIP 48390 | 12.33 |