C/2014 E2 (Jacques)
Metadata
| Parameter | Value |
|---|---|
| Designation | C/2014 E2 (Jacques) |
| Type | C |
| Perihelion (tp_cal, UTC) | 2014-07-02T12:20:22.404480Z |
| Orbit solution date (soln_date, UTC) | 2021-04-15T23:32:50Z |
| Obs used | 4812 |
| NEO | - |
| M1 | 12.000 |
| K1 | 6.500 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2014-08-02.0000000 |
| e | 0.99903625 |
| q (au) | 0.663916 |
| a (au) | 688.887878 |
| i (deg) | 156.392754 |
| Ω (om, deg) | 56.391597 |
| ω (w, deg) | 344.037051 |
| M (ma, deg) | 0.001662 |
Magnitude
Scatter + Global Linear
$$ M_a = (11.111 + 3.563\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 11.111 |
| n | 3.563 |
| gf | 1.000 |
| gb | -0.909 |
| k | 0.991 |
| δ90 | 9.677 |
| 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 |
|---|---|---|---|
| 2014-02-23 | 2014-04-03 | +6.1865 | -2.097 |
| 2014-04-03 | 2014-06-29 | +14.8621 | -3.609 |
| 2014-07-08 | 2014-08-30 | +9.4649 | -1.555 |
| 2014-08-30 | 2015-06-08 | -2.1676 | -0.724 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 17:55:10.09 | -10:21:26.0 | HIP 87829 | 21.44 |
| 2026-05-12 12:00 | 17:55:06.52 | -10:21:17.6 | HIP 87829 | 22.16 |
| 2026-05-13 00:00 | 17:55:02.93 | -10:21:09.3 | HIP 87829 | 22.89 |
| 2026-05-13 12:00 | 17:54:59.32 | -10:21:01.1 | HIP 87829 | 23.64 |
| 2026-05-14 00:00 | 17:54:55.69 | -10:20:52.9 | HIP 87829 | 24.40 |
| 2026-05-14 12:00 | 17:54:52.03 | -10:20:44.9 | HIP 87552 | 24.75 |
| 2026-05-15 00:00 | 17:54:48.36 | -10:20:37.0 | HIP 87552 | 23.86 |
| 2026-05-15 12:00 | 17:54:44.66 | -10:20:29.1 | HIP 87552 | 22.96 |
| 2026-05-16 00:00 | 17:54:40.93 | -10:20:21.4 | HIP 87552 | 22.06 |
| 2026-05-16 12:00 | 17:54:37.19 | -10:20:13.7 | HIP 87552 | 21.15 |
| 2026-05-17 00:00 | 17:54:33.43 | -10:20:06.2 | HIP 87552 | 20.25 |
| 2026-05-17 12:00 | 17:54:29.64 | -10:19:58.7 | HIP 87552 | 19.34 |
| 2026-05-18 00:00 | 17:54:25.84 | -10:19:51.4 | HIP 87552 | 18.42 |
| 2026-05-18 12:00 | 17:54:22.01 | -10:19:44.1 | HIP 87552 | 17.51 |
| 2026-05-19 00:00 | 17:54:18.17 | -10:19:36.9 | HIP 87552 | 16.59 |
| 2026-05-19 12:00 | 17:54:14.31 | -10:19:29.9 | HIP 87552 | 15.68 |
| 2026-05-20 00:00 | 17:54:10.42 | -10:19:22.9 | HIP 87552 | 14.76 |
| 2026-05-20 12:00 | 17:54:06.52 | -10:19:16.0 | HIP 87552 | 13.85 |
| 2026-05-21 00:00 | 17:54:02.60 | -10:19:09.3 | HIP 87552 | 12.94 |
| 2026-05-21 12:00 | 17:53:58.66 | -10:19:02.6 | HIP 87552 | 12.03 |
| 2026-05-22 00:00 | 17:53:54.71 | -10:18:56.1 | HIP 87552 | 11.13 |
| 2026-05-22 12:00 | 17:53:50.73 | -10:18:49.6 | HIP 87552 | 10.24 |
| 2026-05-23 00:00 | 17:53:46.74 | -10:18:43.3 | HIP 87552 | 9.36 |
| 2026-05-23 12:00 | 17:53:42.74 | -10:18:37.0 | HIP 87552 | 8.50 |
| 2026-05-24 00:00 | 17:53:38.71 | -10:18:30.9 | HIP 87552 | 7.67 |
| 2026-05-24 12:00 | 17:53:34.67 | -10:18:24.8 | HIP 87552 | 6.88 |
| 2026-05-25 00:00 | 17:53:30.62 | -10:18:18.9 | HIP 87552 | 6.15 |
| 2026-05-25 12:00 | 17:53:26.54 | -10:18:13.0 | HIP 87552 | 5.50 |
| 2026-05-26 00:00 | 17:53:22.46 | -10:18:07.3 | HIP 87552 | 4.96 |
| 2026-05-26 12:00 | 17:53:18.35 | -10:18:01.7 | HIP 87552 | 4.59 |
| 2026-05-27 00:00 | 17:53:14.24 | -10:17:56.2 | HIP 87552 | 4.41 |
| 2026-05-27 12:00 | 17:53:10.11 | -10:17:50.7 | HIP 87552 | 4.47 |
| 2026-05-28 00:00 | 17:53:05.96 | -10:17:45.4 | HIP 87552 | 4.75 |
| 2026-05-28 12:00 | 17:53:01.80 | -10:17:40.2 | HIP 87552 | 5.22 |
| 2026-05-29 00:00 | 17:52:57.63 | -10:17:35.2 | HIP 87552 | 5.83 |
| 2026-05-29 12:00 | 17:52:53.44 | -10:17:30.2 | HIP 87552 | 6.55 |
| 2026-05-30 00:00 | 17:52:49.24 | -10:17:25.3 | HIP 87552 | 7.35 |
| 2026-05-30 12:00 | 17:52:45.03 | -10:17:20.5 | HIP 87552 | 8.20 |
| 2026-05-31 00:00 | 17:52:40.81 | -10:17:15.9 | HIP 87552 | 9.09 |
| 2026-05-31 12:00 | 17:52:36.57 | -10:17:11.3 | HIP 87552 | 10.01 |
| 2026-06-01 00:00 | 17:52:32.33 | -10:17:06.9 | HIP 87552 | 10.96 |
| 2026-06-01 12:00 | 17:52:28.07 | -10:17:02.5 | HIP 87552 | 11.93 |
| 2026-06-02 00:00 | 17:52:23.80 | -10:16:58.3 | HIP 87552 | 12.91 |