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) |
|---|---|---|---|---|
| 2026-07-29 00:00 | 16:08:37.24 | -28:11:20.7 | HIP 79185 | 22.55 |
| 2026-07-29 12:00 | 16:08:31.11 | -28:10:13.8 | HIP 79185 | 22.58 |
| 2026-07-30 00:00 | 16:08:25.20 | -28:09:07.3 | HIP 79185 | 22.72 |
| 2026-07-30 12:00 | 16:08:19.51 | -28:08:01.3 | HIP 79185 | 22.96 |
| 2026-07-31 00:00 | 16:08:14.05 | -28:06:55.7 | HIP 79049 | 23.15 |
| 2026-07-31 12:00 | 16:08:08.81 | -28:05:50.6 | HIP 79049 | 22.02 |
| 2026-08-01 00:00 | 16:08:03.80 | -28:04:46.0 | HIP 79049 | 20.95 |
| 2026-08-01 12:00 | 16:07:59.02 | -28:03:41.9 | HIP 79049 | 19.95 |
| 2026-08-02 00:00 | 16:07:54.46 | -28:02:38.3 | HIP 79049 | 19.02 |
| 2026-08-02 12:00 | 16:07:50.13 | -28:01:35.1 | HIP 79049 | 18.16 |
| 2026-08-03 00:00 | 16:07:46.02 | -28:00:32.5 | HIP 79049 | 17.36 |
| 2026-08-03 12:00 | 16:07:42.14 | -27:59:30.3 | HIP 79049 | 16.63 |
| 2026-08-04 00:00 | 16:07:38.49 | -27:58:28.7 | HIP 79049 | 15.97 |
| 2026-08-04 12:00 | 16:07:35.06 | -27:57:27.6 | HIP 79049 | 15.37 |
| 2026-08-05 00:00 | 16:07:31.86 | -27:56:27.0 | HIP 79049 | 14.85 |
| 2026-08-05 12:00 | 16:07:28.89 | -27:55:27.0 | HIP 78943 | 14.06 |
| 2026-08-06 00:00 | 16:07:26.14 | -27:54:27.5 | HIP 78943 | 12.90 |
| 2026-08-06 12:00 | 16:07:23.62 | -27:53:28.5 | HIP 78943 | 11.77 |
| 2026-08-07 00:00 | 16:07:21.32 | -27:52:30.1 | HIP 78943 | 10.68 |
| 2026-08-07 12:00 | 16:07:19.26 | -27:51:32.2 | HIP 78943 | 9.61 |
| 2026-08-08 00:00 | 16:07:17.42 | -27:50:34.9 | HIP 78943 | 8.58 |
| 2026-08-08 12:00 | 16:07:15.81 | -27:49:38.1 | HIP 78943 | 7.58 |
| 2026-08-09 00:00 | 16:07:14.42 | -27:48:42.0 | HIP 78943 | 6.63 |
| 2026-08-09 12:00 | 16:07:13.26 | -27:47:46.3 | HIP 78943 | 5.72 |
| 2026-08-10 00:00 | 16:07:12.33 | -27:46:51.3 | HIP 78943 | 4.87 |
| 2026-08-10 12:00 | 16:07:11.63 | -27:45:56.8 | HIP 78943 | 4.11 |
| 2026-08-11 00:00 | 16:07:11.15 | -27:45:03.0 | HIP 78943 | 3.48 |
| 2026-08-11 12:00 | 16:07:10.90 | -27:44:09.7 | HIP 78943 | 3.03 |
| 2026-08-12 00:00 | 16:07:10.87 | -27:43:17.0 | HIP 78943 | 2.86 |
| 2026-08-12 12:00 | 16:07:11.07 | -27:42:24.8 | HIP 78943 | 3.00 |
| 2026-08-13 00:00 | 16:07:11.50 | -27:41:33.3 | HIP 78943 | 3.40 |
| 2026-08-13 12:00 | 16:07:12.15 | -27:40:42.4 | HIP 78943 | 3.99 |
| 2026-08-14 00:00 | 16:07:13.03 | -27:39:52.1 | HIP 78943 | 4.69 |
| 2026-08-14 12:00 | 16:07:14.14 | -27:39:02.4 | HIP 78943 | 5.46 |
| 2026-08-15 00:00 | 16:07:15.47 | -27:38:13.3 | HIP 78943 | 6.28 |
| 2026-08-15 12:00 | 16:07:17.02 | -27:37:24.8 | HIP 78943 | 7.13 |
| 2026-08-16 00:00 | 16:07:18.79 | -27:36:36.9 | HIP 78943 | 8.01 |
| 2026-08-16 12:00 | 16:07:20.79 | -27:35:49.6 | HIP 78943 | 8.91 |
| 2026-08-17 00:00 | 16:07:23.01 | -27:35:02.9 | HIP 78943 | 9.83 |
| 2026-08-17 12:00 | 16:07:25.46 | -27:34:16.9 | HIP 78943 | 10.77 |
| 2026-08-18 00:00 | 16:07:28.12 | -27:33:31.5 | HIP 78943 | 11.72 |
| 2026-08-18 12:00 | 16:07:31.01 | -27:32:46.7 | HIP 78943 | 12.70 |
| 2026-08-19 00:00 | 16:07:34.12 | -27:32:02.5 | HIP 78943 | 13.70 |