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 | -21.8444 | +23.380 |
| 2017-08-25 | 2018-08-04 | -2.7207 | +3.323 |
| 2018-08-04 | 2019-08-10 | +28.9826 | -27.612 |
| 2019-08-10 | 2021-05-07 | -11.4030 | +9.708 |
| 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) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 10:18:16.75 | +24:10:47.2 | HIP 50528 | 16.94 |
| 2026-02-03 12:00 | 10:18:04.58 | +24:11:15.6 | HIP 50528 | 18.86 |
| 2026-02-04 00:00 | 10:17:52.37 | +24:11:43.8 | HIP 50528 | 20.99 |
| 2026-02-04 12:00 | 10:17:40.14 | +24:12:11.8 | HIP 50342 | 18.97 |
| 2026-02-05 00:00 | 10:17:27.88 | +24:12:39.5 | HIP 50342 | 16.92 |
| 2026-02-05 12:00 | 10:17:15.59 | +24:13:07.0 | HIP 50342 | 15.13 |
| 2026-02-06 00:00 | 10:17:03.28 | +24:13:34.3 | HIP 50342 | 13.70 |
| 2026-02-06 12:00 | 10:16:50.94 | +24:14:01.4 | HIP 50342 | 12.76 |
| 2026-02-07 00:00 | 10:16:38.58 | +24:14:28.1 | HIP 50342 | 12.41 |
| 2026-02-07 12:00 | 10:16:26.19 | +24:14:54.7 | HIP 50342 | 12.72 |
| 2026-02-08 00:00 | 10:16:13.78 | +24:15:21.0 | HIP 50342 | 13.64 |
| 2026-02-08 12:00 | 10:16:01.36 | +24:15:47.0 | HIP 50342 | 15.06 |
| 2026-02-09 00:00 | 10:15:48.91 | +24:16:12.7 | HIP 50342 | 16.86 |
| 2026-02-09 12:00 | 10:15:36.44 | +24:16:38.2 | HIP 50342 | 18.93 |
| 2026-02-10 00:00 | 10:15:23.96 | +24:17:03.4 | HIP 50342 | 21.19 |
| 2026-02-10 12:00 | 10:15:11.46 | +24:17:28.3 | HIP 50342 | 23.59 |
| 2026-02-11 00:00 | 10:14:58.94 | +24:17:53.0 | HIP 50342 | 26.09 |
| 2026-02-11 12:00 | 10:14:46.41 | +24:18:17.3 | HIP 50342 | 28.67 |
| 2026-02-12 00:00 | 10:14:33.87 | +24:18:41.3 | HIP 50134 | 30.55 |
| 2026-02-12 12:00 | 10:14:21.31 | +24:19:05.1 | HIP 50134 | 30.45 |
| 2026-02-13 00:00 | 10:14:08.74 | +24:19:28.5 | HIP 50134 | 30.61 |
| 2026-02-13 12:00 | 10:13:56.16 | +24:19:51.6 | HIP 50134 | 31.04 |
| 2026-02-14 00:00 | 10:13:43.58 | +24:20:14.4 | HIP 50134 | 31.72 |
| 2026-02-14 12:00 | 10:13:30.98 | +24:20:36.9 | HIP 50134 | 32.64 |
| 2026-02-15 00:00 | 10:13:18.38 | +24:20:59.0 | HIP 50134 | 33.78 |
| 2026-02-15 12:00 | 10:13:05.78 | +24:21:20.8 | HIP 50003 | 33.39 |
| 2026-02-16 00:00 | 10:12:53.17 | +24:21:42.2 | HIP 50003 | 32.43 |
| 2026-02-16 12:00 | 10:12:40.55 | +24:22:03.3 | HIP 50003 | 31.71 |
| 2026-02-17 00:00 | 10:12:27.94 | +24:22:24.1 | HIP 50003 | 31.25 |
| 2026-02-17 12:00 | 10:12:15.32 | +24:22:44.5 | HIP 50003 | 31.06 |
| 2026-02-18 00:00 | 10:12:02.70 | +24:23:04.5 | HIP 50003 | 31.14 |
| 2026-02-18 12:00 | 10:11:50.09 | +24:23:24.2 | HIP 50003 | 31.50 |
| 2026-02-19 00:00 | 10:11:37.47 | +24:23:43.5 | HIP 50003 | 32.11 |
| 2026-02-19 12:00 | 10:11:24.86 | +24:24:02.5 | HIP 49749 | 29.65 |
| 2026-02-20 00:00 | 10:11:12.26 | +24:24:21.0 | HIP 49749 | 26.82 |
| 2026-02-20 12:00 | 10:10:59.66 | +24:24:39.2 | HIP 49749 | 24.00 |
| 2026-02-21 00:00 | 10:10:47.07 | +24:24:57.0 | HIP 49749 | 21.21 |
| 2026-02-21 12:00 | 10:10:34.48 | +24:25:14.4 | HIP 49749 | 18.46 |
| 2026-02-22 00:00 | 10:10:21.91 | +24:25:31.4 | HIP 49749 | 15.75 |
| 2026-02-22 12:00 | 10:10:09.34 | +24:25:48.0 | HIP 49749 | 13.12 |
| 2026-02-23 00:00 | 10:09:56.79 | +24:26:04.2 | HIP 49749 | 10.62 |
| 2026-02-23 12:00 | 10:09:44.25 | +24:26:20.0 | HIP 49749 | 8.37 |
| 2026-02-24 00:00 | 10:09:31.72 | +24:26:35.4 | HIP 49749 | 6.62 |