64P/Swift-Gehrels
Metadata
| Parameter | Value |
|---|---|
| Designation | 64P/Swift-Gehrels |
| Type | P |
| Perihelion (tp_cal, UTC) | 2018-11-03T21:53:15.495360Z |
| Orbit solution date (soln_date, UTC) | 2023-12-21T08:26:18Z |
| Obs used | 3436 |
| NEO | - |
| M1 | 14.500 |
| K1 | 6.000 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2017-12-09.0000000 |
| e | 0.68732017 |
| q (au) | 1.393350 |
| a (au) | 4.456157 |
| i (deg) | 8.948393 |
| Ω (om, deg) | 300.000979 |
| ω (w, deg) | 97.144197 |
| M (ma, deg) | 325.433022 |
Magnitude
Scatter + Global Linear
$$ M_a = (12.980 + 2.682\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 12.980 |
| n | 2.682 |
| gf | 1.000 |
| gb | -0.500 |
| 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 |
|---|---|---|---|
| 2018-05-25 | 2018-08-18 | +18.4191 | -3.252 |
| 2018-08-18 | 2018-11-03 | +26.1368 | -4.376 |
| 2018-11-03 | 2019-05-06 | +1.5754 | -1.769 |
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) |
|---|---|---|---|---|
| 2026-09-20 00:00 | 16:17:59.48 | -27:05:39.6 | HIP 79987 | 25.56 |
| 2026-09-20 12:00 | 16:18:15.39 | -27:05:32.7 | HIP 79987 | 22.52 |
| 2026-09-21 00:00 | 16:18:31.48 | -27:05:26.3 | HIP 79987 | 19.64 |
| 2026-09-21 12:00 | 16:18:47.74 | -27:05:20.4 | HIP 79987 | 17.00 |
| 2026-09-22 00:00 | 16:19:04.17 | -27:05:14.9 | HIP 79987 | 14.78 |
| 2026-09-22 12:00 | 16:19:20.76 | -27:05:09.8 | HIP 79987 | 13.21 |
| 2026-09-23 00:00 | 16:19:37.52 | -27:05:05.2 | HIP 79987 | 12.57 |
| 2026-09-23 12:00 | 16:19:54.45 | -27:05:01.1 | HIP 79987 | 13.04 |
| 2026-09-24 00:00 | 16:20:11.54 | -27:04:57.4 | HIP 79987 | 14.53 |
| 2026-09-24 12:00 | 16:20:28.80 | -27:04:54.1 | HIP 80123 | 14.23 |
| 2026-09-25 00:00 | 16:20:46.21 | -27:04:51.3 | HIP 80123 | 11.53 |
| 2026-09-25 12:00 | 16:21:03.80 | -27:04:48.9 | HIP 80123 | 9.64 |
| 2026-09-26 00:00 | 16:21:21.54 | -27:04:46.9 | HIP 80123 | 9.14 |
| 2026-09-26 12:00 | 16:21:39.44 | -27:04:45.3 | HIP 80123 | 10.27 |
| 2026-09-27 00:00 | 16:21:57.51 | -27:04:44.1 | HIP 80123 | 12.63 |
| 2026-09-27 12:00 | 16:22:15.73 | -27:04:43.4 | HIP 80123 | 15.71 |
| 2026-09-28 00:00 | 16:22:34.12 | -27:04:43.0 | HIP 80123 | 19.18 |
| 2026-09-28 12:00 | 16:22:52.66 | -27:04:43.1 | HIP 80387 | 22.19 |
| 2026-09-29 00:00 | 16:23:11.35 | -27:04:43.5 | HIP 80387 | 18.13 |
| 2026-09-29 12:00 | 16:23:30.21 | -27:04:44.4 | HIP 80387 | 14.08 |
| 2026-09-30 00:00 | 16:23:49.21 | -27:04:45.6 | HIP 80387 | 10.13 |
| 2026-09-30 12:00 | 16:24:08.38 | -27:04:47.2 | HIP 80387 | 6.51 |
| 2026-10-01 00:00 | 16:24:27.70 | -27:04:49.2 | HIP 80387 | 4.29 |
| 2026-10-01 12:00 | 16:24:47.17 | -27:04:51.5 | HIP 80387 | 5.62 |
| 2026-10-02 00:00 | 16:25:06.79 | -27:04:54.2 | HIP 80387 | 9.10 |
| 2026-10-02 12:00 | 16:25:26.57 | -27:04:57.3 | HIP 80387 | 13.15 |
| 2026-10-03 00:00 | 16:25:46.50 | -27:05:00.7 | HIP 80565 | 16.06 |
| 2026-10-03 12:00 | 16:26:06.58 | -27:05:04.5 | HIP 80565 | 11.71 |
| 2026-10-04 00:00 | 16:26:26.81 | -27:05:08.6 | HIP 80565 | 7.46 |
| 2026-10-04 12:00 | 16:26:47.19 | -27:05:13.0 | HIP 80565 | 3.82 |
| 2026-10-05 00:00 | 16:27:07.72 | -27:05:17.8 | HIP 80565 | 3.84 |
| 2026-10-05 12:00 | 16:27:28.40 | -27:05:23.0 | HIP 80586 | 6.94 |
| 2026-10-06 00:00 | 16:27:49.22 | -27:05:28.4 | HIP 80586 | 10.06 |
| 2026-10-06 12:00 | 16:28:10.19 | -27:05:34.2 | HIP 80586 | 14.07 |
| 2026-10-07 00:00 | 16:28:31.31 | -27:05:40.3 | HIP 80586 | 18.43 |
| 2026-10-07 12:00 | 16:28:52.57 | -27:05:46.7 | HIP 80753 | 17.53 |
| 2026-10-08 00:00 | 16:29:13.97 | -27:05:53.4 | HIP 80753 | 16.64 |
| 2026-10-08 12:00 | 16:29:35.52 | -27:06:00.4 | HIP 80846 | 14.00 |
| 2026-10-09 00:00 | 16:29:57.22 | -27:06:07.7 | HIP 80846 | 9.51 |
| 2026-10-09 12:00 | 16:30:19.05 | -27:06:15.3 | HIP 80846 | 5.60 |
| 2026-10-10 00:00 | 16:30:41.02 | -27:06:23.2 | HIP 80846 | 4.41 |
| 2026-10-10 12:00 | 16:31:03.14 | -27:06:31.3 | HIP 80846 | 7.47 |
| 2026-10-11 00:00 | 16:31:25.39 | -27:06:39.8 | HIP 80846 | 11.88 |