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
$$ M_a = (11.109 + 3.567\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 11.109 |
| n | 3.567 |
| gf | 1.000 |
| gb | -0.909 |
| k | 0.991 |
| δ90 | 9.999 |
| 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 | +6.2241 | -2.108 |
| 2014-04-03 | 2014-06-29 | +14.8579 | -3.611 |
| 2014-07-08 | 2014-08-30 | +9.4997 | -1.553 |
| 2014-08-30 | 2015-06-08 | -2.2390 | -0.692 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) | RA (J2000) | Dec (J2000) | Nearest HIP | Dist from HIP (arcmin) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 17:56:23.03 | -10:59:00.5 | HIP 87921 | 37.51 |
| 2026-02-03 12:00 | 17:56:25.88 | -10:58:52.1 | HIP 87921 | 37.31 |
| 2026-02-04 00:00 | 17:56:28.71 | -10:58:43.6 | HIP 87921 | 37.12 |
| 2026-02-04 12:00 | 17:56:31.51 | -10:58:35.0 | HIP 87921 | 36.96 |
| 2026-02-05 00:00 | 17:56:34.29 | -10:58:26.3 | HIP 87921 | 36.80 |
| 2026-02-05 12:00 | 17:56:37.04 | -10:58:17.5 | HIP 87921 | 36.67 |
| 2026-02-06 00:00 | 17:56:39.77 | -10:58:08.6 | HIP 87921 | 36.55 |
| 2026-02-06 12:00 | 17:56:42.46 | -10:57:59.7 | HIP 87921 | 36.44 |
| 2026-02-07 00:00 | 17:56:45.14 | -10:57:50.6 | HIP 87921 | 36.35 |
| 2026-02-07 12:00 | 17:56:47.78 | -10:57:41.5 | HIP 87921 | 36.28 |
| 2026-02-08 00:00 | 17:56:50.40 | -10:57:32.3 | HIP 87921 | 36.22 |
| 2026-02-08 12:00 | 17:56:52.99 | -10:57:23.0 | HIP 87921 | 36.18 |
| 2026-02-09 00:00 | 17:56:55.55 | -10:57:13.6 | HIP 87921 | 36.16 |
| 2026-02-09 12:00 | 17:56:58.08 | -10:57:04.1 | HIP 87921 | 36.14 |
| 2026-02-10 00:00 | 17:57:00.59 | -10:56:54.6 | HIP 87921 | 36.15 |
| 2026-02-10 12:00 | 17:57:03.07 | -10:56:45.0 | HIP 87921 | 36.16 |
| 2026-02-11 00:00 | 17:57:05.52 | -10:56:35.3 | HIP 87921 | 36.19 |
| 2026-02-11 12:00 | 17:57:07.94 | -10:56:25.5 | HIP 87921 | 36.24 |
| 2026-02-12 00:00 | 17:57:10.33 | -10:56:15.6 | HIP 87921 | 36.29 |
| 2026-02-12 12:00 | 17:57:12.69 | -10:56:05.7 | HIP 87921 | 36.36 |
| 2026-02-13 00:00 | 17:57:15.02 | -10:55:55.7 | HIP 87921 | 36.44 |
| 2026-02-13 12:00 | 17:57:17.33 | -10:55:45.6 | HIP 87921 | 36.53 |
| 2026-02-14 00:00 | 17:57:19.60 | -10:55:35.4 | HIP 87921 | 36.64 |
| 2026-02-14 12:00 | 17:57:21.85 | -10:55:25.2 | HIP 87921 | 36.75 |
| 2026-02-15 00:00 | 17:57:24.06 | -10:55:14.8 | HIP 87921 | 36.88 |
| 2026-02-15 12:00 | 17:57:26.24 | -10:55:04.5 | HIP 87921 | 37.01 |
| 2026-02-16 00:00 | 17:57:28.39 | -10:54:54.0 | HIP 87921 | 37.16 |
| 2026-02-16 12:00 | 17:57:30.52 | -10:54:43.5 | HIP 87921 | 37.31 |
| 2026-02-17 00:00 | 17:57:32.61 | -10:54:32.9 | HIP 87921 | 37.47 |
| 2026-02-17 12:00 | 17:57:34.67 | -10:54:22.2 | HIP 87921 | 37.64 |
| 2026-02-18 00:00 | 17:57:36.69 | -10:54:11.5 | HIP 87921 | 37.82 |
| 2026-02-18 12:00 | 17:57:38.69 | -10:54:00.7 | HIP 87921 | 38.01 |
| 2026-02-19 00:00 | 17:57:40.65 | -10:53:49.8 | HIP 87921 | 38.20 |
| 2026-02-19 12:00 | 17:57:42.59 | -10:53:38.8 | HIP 87921 | 38.40 |
| 2026-02-20 00:00 | 17:57:44.49 | -10:53:27.8 | HIP 87921 | 38.61 |
| 2026-02-20 12:00 | 17:57:46.36 | -10:53:16.8 | HIP 87921 | 38.82 |
| 2026-02-21 00:00 | 17:57:48.19 | -10:53:05.7 | HIP 87921 | 39.04 |
| 2026-02-21 12:00 | 17:57:50.00 | -10:52:54.5 | HIP 87921 | 39.26 |
| 2026-02-22 00:00 | 17:57:51.77 | -10:52:43.2 | HIP 87921 | 39.49 |
| 2026-02-22 12:00 | 17:57:53.50 | -10:52:31.9 | HIP 87921 | 39.72 |
| 2026-02-23 00:00 | 17:57:55.21 | -10:52:20.6 | HIP 87921 | 39.96 |
| 2026-02-23 12:00 | 17:57:56.88 | -10:52:09.1 | HIP 87921 | 40.20 |
| 2026-02-24 00:00 | 17:57:58.52 | -10:51:57.7 | HIP 87921 | 40.44 |