C/2011 L4 (PANSTARRS)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2011 L4 (PANSTARRS) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2013-03-10T04:04:44.544000Z |
| Orbit solution date (soln_date, UTC) | 2021-04-15T23:31:52Z |
| Obs used | 5413 |
| NEO | - |
| M1 | 7.800 |
| K1 | 6.500 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2013-03-14.0000000 |
| e | 1.00003277 |
| q (au) | 0.301544 |
| a (au) | -9202.649647 |
| i (deg) | 84.208197 |
| Ω (om, deg) | 65.665886 |
| ω (w, deg) | 333.651638 |
| M (ma, deg) | 0.000004 |
Magnitude
Scatter + Global Linear
$$ M_a = (8.602 + 5.378\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 8.602 |
| n | 5.378 |
| gf | 1.000 |
| gb | -0.915 |
| k | 0.815 |
| δ90 | 9.995 |
| 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 |
|---|---|---|---|
| 2011-05-21 | 2012-04-20 | +7.9822 | -7.065 |
| 2012-04-20 | 2012-07-07 | +11.8613 | -8.636 |
| 2012-07-07 | 2013-03-09 | -1.6663 | -1.493 |
| 2013-03-10 | 2013-04-20 | +2.6306 | -0.220 |
| 2013-04-20 | 2014-08-27 | +0.8922 | -0.673 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-06-01 00:00 | 16:25:55.65 | +17:29:23.3 | HIP 80465 | 13.13 |
| 2026-06-01 12:00 | 16:25:51.66 | +17:29:27.6 | HIP 80465 | 12.72 |
| 2026-06-02 00:00 | 16:25:47.68 | +17:29:31.5 | HIP 80465 | 12.37 |
| 2026-06-02 12:00 | 16:25:43.69 | +17:29:35.2 | HIP 80465 | 12.08 |
| 2026-06-03 00:00 | 16:25:39.71 | +17:29:38.5 | HIP 80465 | 11.85 |
| 2026-06-03 12:00 | 16:25:35.74 | +17:29:41.5 | HIP 80465 | 11.70 |
| 2026-06-04 00:00 | 16:25:31.77 | +17:29:44.2 | HIP 80465 | 11.61 |
| 2026-06-04 12:00 | 16:25:27.80 | +17:29:46.6 | HIP 80465 | 11.59 |
| 2026-06-05 00:00 | 16:25:23.83 | +17:29:48.6 | HIP 80465 | 11.65 |
| 2026-06-05 12:00 | 16:25:19.87 | +17:29:50.4 | HIP 80465 | 11.77 |
| 2026-06-06 00:00 | 16:25:15.91 | +17:29:51.8 | HIP 80465 | 11.97 |
| 2026-06-06 12:00 | 16:25:11.96 | +17:29:52.9 | HIP 80465 | 12.23 |
| 2026-06-07 00:00 | 16:25:08.02 | +17:29:53.7 | HIP 80392 | 12.20 |
| 2026-06-07 12:00 | 16:25:04.08 | +17:29:54.2 | HIP 80392 | 11.57 |
| 2026-06-08 00:00 | 16:25:00.14 | +17:29:54.3 | HIP 80392 | 10.99 |
| 2026-06-08 12:00 | 16:24:56.21 | +17:29:54.2 | HIP 80392 | 10.47 |
| 2026-06-09 00:00 | 16:24:52.29 | +17:29:53.7 | HIP 80392 | 10.02 |
| 2026-06-09 12:00 | 16:24:48.37 | +17:29:52.9 | HIP 80392 | 9.63 |
| 2026-06-10 00:00 | 16:24:44.46 | +17:29:51.8 | HIP 80392 | 9.34 |
| 2026-06-10 12:00 | 16:24:40.56 | +17:29:50.3 | HIP 80392 | 9.13 |
| 2026-06-11 00:00 | 16:24:36.67 | +17:29:48.6 | HIP 80392 | 9.02 |
| 2026-06-11 12:00 | 16:24:32.78 | +17:29:46.5 | HIP 80357 | 8.84 |
| 2026-06-12 00:00 | 16:24:28.90 | +17:29:44.1 | HIP 80357 | 8.36 |
| 2026-06-12 12:00 | 16:24:25.03 | +17:29:41.4 | HIP 80357 | 7.95 |
| 2026-06-13 00:00 | 16:24:21.17 | +17:29:38.3 | HIP 80357 | 7.62 |
| 2026-06-13 12:00 | 16:24:17.32 | +17:29:35.0 | HIP 80357 | 7.40 |
| 2026-06-14 00:00 | 16:24:13.47 | +17:29:31.3 | HIP 80357 | 7.28 |
| 2026-06-14 12:00 | 16:24:09.64 | +17:29:27.3 | HIP 80357 | 7.26 |
| 2026-06-15 00:00 | 16:24:05.82 | +17:29:23.0 | HIP 80357 | 7.36 |
| 2026-06-15 12:00 | 16:24:02.01 | +17:29:18.4 | HIP 80357 | 7.56 |
| 2026-06-16 00:00 | 16:23:58.20 | +17:29:13.5 | HIP 80357 | 7.86 |
| 2026-06-16 12:00 | 16:23:54.41 | +17:29:08.2 | HIP 80357 | 8.24 |
| 2026-06-17 00:00 | 16:23:50.63 | +17:29:02.7 | HIP 80357 | 8.69 |
| 2026-06-17 12:00 | 16:23:46.87 | +17:28:56.8 | HIP 80357 | 9.21 |
| 2026-06-18 00:00 | 16:23:43.11 | +17:28:50.6 | HIP 80262 | 8.85 |
| 2026-06-18 12:00 | 16:23:39.37 | +17:28:44.1 | HIP 80262 | 7.95 |
| 2026-06-19 00:00 | 16:23:35.64 | +17:28:37.2 | HIP 80262 | 7.05 |
| 2026-06-19 12:00 | 16:23:31.92 | +17:28:30.1 | HIP 80262 | 6.16 |
| 2026-06-20 00:00 | 16:23:28.21 | +17:28:22.7 | HIP 80262 | 5.27 |
| 2026-06-20 12:00 | 16:23:24.52 | +17:28:14.9 | HIP 80262 | 4.39 |
| 2026-06-21 00:00 | 16:23:20.84 | +17:28:06.8 | HIP 80262 | 3.51 |
| 2026-06-21 12:00 | 16:23:17.18 | +17:27:58.5 | HIP 80262 | 2.63 |
| 2026-06-22 00:00 | 16:23:13.53 | +17:27:49.8 | HIP 80262 | 1.78 |