67P/Churyumov-Gerasimenko
Metadata
| Parameter | Value |
|---|---|
| Designation | 67P/Churyumov-Gerasimenko |
| Type | P |
| Perihelion (tp_cal, UTC) | 2015-08-13T02:07:40.042560Z |
| Orbit solution date (soln_date, UTC) | 2024-02-01T08:49:50Z |
| Obs used | 8608 |
| NEO | Yes |
| M1 | 12.900 |
| K1 | 7.500 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2015-10-10.0000000 |
| e | 0.64090813 |
| q (au) | 1.243266 |
| a (au) | 3.462249 |
| i (deg) | 7.040295 |
| Ω (om, deg) | 50.135574 |
| ω (w, deg) | 12.798250 |
| M (ma, deg) | 8.859927 |
Magnitude
Scatter + Global Linear
$$ M_a = (12.809 + 3.261\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 12.809 |
| n | 3.261 |
| gf | 0.959 |
| gb | -0.500 |
| k | 0.800 |
| δ90 | 1.384 |
| 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 |
|---|---|---|---|
| 2021-02-02 | 2023-04-26 | -0.2979 | -0.513 |
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 | 16:56:55.81 | -26:06:18.6 | HIP 83055 | 18.37 |
| 2026-07-29 12:00 | 16:56:43.95 | -26:05:48.9 | HIP 82977 | 19.85 |
| 2026-07-30 00:00 | 16:56:32.32 | -26:05:19.4 | HIP 82977 | 20.71 |
| 2026-07-30 12:00 | 16:56:20.92 | -26:04:50.1 | HIP 82977 | 21.83 |
| 2026-07-31 00:00 | 16:56:09.76 | -26:04:20.9 | HIP 82977 | 23.16 |
| 2026-07-31 12:00 | 16:55:58.84 | -26:03:52.0 | HIP 82977 | 24.65 |
| 2026-08-01 00:00 | 16:55:48.14 | -26:03:23.2 | HIP 82708 | 23.92 |
| 2026-08-01 12:00 | 16:55:37.69 | -26:02:54.7 | HIP 82708 | 21.74 |
| 2026-08-02 00:00 | 16:55:27.47 | -26:02:26.3 | HIP 82708 | 19.65 |
| 2026-08-02 12:00 | 16:55:17.50 | -26:01:58.2 | HIP 82708 | 17.67 |
| 2026-08-03 00:00 | 16:55:07.76 | -26:01:30.3 | HIP 82708 | 15.81 |
| 2026-08-03 12:00 | 16:54:58.26 | -26:01:02.6 | HIP 82708 | 14.10 |
| 2026-08-04 00:00 | 16:54:49.00 | -26:00:35.1 | HIP 82708 | 12.56 |
| 2026-08-04 12:00 | 16:54:39.98 | -26:00:07.9 | HIP 82708 | 11.24 |
| 2026-08-05 00:00 | 16:54:31.20 | -25:59:41.0 | HIP 82708 | 10.20 |
| 2026-08-05 12:00 | 16:54:22.67 | -25:59:14.3 | HIP 82708 | 9.49 |
| 2026-08-06 00:00 | 16:54:14.38 | -25:58:47.8 | HIP 82708 | 9.15 |
| 2026-08-06 12:00 | 16:54:06.33 | -25:58:21.6 | HIP 82708 | 9.19 |
| 2026-08-07 00:00 | 16:53:58.53 | -25:57:55.7 | HIP 82708 | 9.57 |
| 2026-08-07 12:00 | 16:53:50.97 | -25:57:30.1 | HIP 82708 | 10.23 |
| 2026-08-08 00:00 | 16:53:43.66 | -25:57:04.7 | HIP 82708 | 11.09 |
| 2026-08-08 12:00 | 16:53:36.59 | -25:56:39.6 | HIP 82708 | 12.09 |
| 2026-08-09 00:00 | 16:53:29.77 | -25:56:14.9 | HIP 82708 | 13.17 |
| 2026-08-09 12:00 | 16:53:23.20 | -25:55:50.4 | HIP 82708 | 14.29 |
| 2026-08-10 00:00 | 16:53:16.87 | -25:55:26.2 | HIP 82708 | 15.44 |
| 2026-08-10 12:00 | 16:53:10.79 | -25:55:02.3 | HIP 82708 | 16.59 |
| 2026-08-11 00:00 | 16:53:04.96 | -25:54:38.8 | HIP 82708 | 17.73 |
| 2026-08-11 12:00 | 16:52:59.38 | -25:54:15.5 | HIP 82708 | 18.84 |
| 2026-08-12 00:00 | 16:52:54.05 | -25:53:52.6 | HIP 82538 | 19.79 |
| 2026-08-12 12:00 | 16:52:48.96 | -25:53:30.0 | HIP 82538 | 18.97 |
| 2026-08-13 00:00 | 16:52:44.13 | -25:53:07.7 | HIP 82538 | 18.22 |
| 2026-08-13 12:00 | 16:52:39.54 | -25:52:45.8 | HIP 82538 | 17.54 |
| 2026-08-14 00:00 | 16:52:35.21 | -25:52:24.1 | HIP 82538 | 16.93 |
| 2026-08-14 12:00 | 16:52:31.12 | -25:52:02.9 | HIP 82538 | 16.37 |
| 2026-08-15 00:00 | 16:52:27.29 | -25:51:41.9 | HIP 82538 | 15.87 |
| 2026-08-15 12:00 | 16:52:23.70 | -25:51:21.4 | HIP 82538 | 15.42 |
| 2026-08-16 00:00 | 16:52:20.36 | -25:51:01.1 | HIP 82538 | 15.01 |
| 2026-08-16 12:00 | 16:52:17.27 | -25:50:41.2 | HIP 82538 | 14.65 |
| 2026-08-17 00:00 | 16:52:14.43 | -25:50:21.7 | HIP 82538 | 14.33 |
| 2026-08-17 12:00 | 16:52:11.84 | -25:50:02.5 | HIP 82538 | 14.04 |
| 2026-08-18 00:00 | 16:52:09.49 | -25:49:43.7 | HIP 82538 | 13.77 |
| 2026-08-18 12:00 | 16:52:07.40 | -25:49:25.2 | HIP 82538 | 13.53 |
| 2026-08-19 00:00 | 16:52:05.55 | -25:49:07.1 | HIP 82538 | 13.30 |