47P/Ashbrook-Jackson
Metadata
| Parameter | Value |
|---|---|
| Designation | 47P/Ashbrook-Jackson |
| Type | P |
| Perihelion (tp_cal, UTC) | 2025-10-26T16:05:01.651200Z |
| Orbit solution date (soln_date, UTC) | 2026-09-21T09:56:28Z |
| Obs used | 2403 |
| NEO | - |
| M1 | 13.100 |
| K1 | 4.750 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2021-12-10.0000000 |
| e | 0.31853712 |
| q (au) | 2.809978 |
| a (au) | 4.123450 |
| i (deg) | 13.040621 |
| Ω (om, deg) | 356.920755 |
| ω (w, deg) | 357.660471 |
| M (ma, deg) | 193.243932 |
Magnitude
Scatter + Global Linear
$$ M_a = (7.989 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 7.989 |
| n | 6.000 |
| gf | 1.000 |
| gb | -0.744 |
| k | 0.992 |
| 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 |
|---|---|---|---|
| 2022-03-25 | 2025-10-26 | +0.1225 | -0.035 |
| 2025-10-29 | 2026-09-11 | +29.2429 | -13.320 |
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 | 05:20:22.67 | +36:08:04.4 | HIP 24795 | 17.71 |
| 2026-09-20 12:00 | 05:20:40.77 | +36:10:33.6 | HIP 25084 | 18.45 |
| 2026-09-21 00:00 | 05:20:58.56 | +36:13:02.8 | HIP 25084 | 14.84 |
| 2026-09-21 12:00 | 05:21:16.04 | +36:15:31.9 | HIP 25084 | 11.82 |
| 2026-09-22 00:00 | 05:21:33.21 | +36:18:00.9 | HIP 25084 | 9.88 |
| 2026-09-22 12:00 | 05:21:50.07 | +36:20:29.9 | HIP 25084 | 9.61 |
| 2026-09-23 00:00 | 05:22:06.62 | +36:22:58.7 | HIP 25056 | 8.68 |
| 2026-09-23 12:00 | 05:22:22.85 | +36:25:27.6 | HIP 25056 | 8.17 |
| 2026-09-24 00:00 | 05:22:38.77 | +36:27:56.3 | HIP 25056 | 9.51 |
| 2026-09-24 12:00 | 05:22:54.36 | +36:30:25.0 | HIP 25056 | 12.06 |
| 2026-09-25 00:00 | 05:23:09.64 | +36:32:53.6 | HIP 25238 | 12.28 |
| 2026-09-25 12:00 | 05:23:24.59 | +36:35:22.1 | HIP 25238 | 12.65 |
| 2026-09-26 00:00 | 05:23:39.21 | +36:37:50.6 | HIP 25238 | 14.15 |
| 2026-09-26 12:00 | 05:23:53.51 | +36:40:19.0 | HIP 25238 | 16.42 |
| 2026-09-27 00:00 | 05:24:07.48 | +36:42:47.2 | HIP 25238 | 19.16 |
| 2026-09-27 12:00 | 05:24:21.12 | +36:45:15.4 | HIP 25238 | 22.18 |
| 2026-09-28 00:00 | 05:24:34.42 | +36:47:43.5 | HIP 25238 | 25.35 |
| 2026-09-28 12:00 | 05:24:47.39 | +36:50:11.5 | HIP 25225 | 24.77 |
| 2026-09-29 00:00 | 05:25:00.02 | +36:52:39.5 | HIP 25225 | 24.21 |
| 2026-09-29 12:00 | 05:25:12.32 | +36:55:07.3 | HIP 25225 | 24.12 |
| 2026-09-30 00:00 | 05:25:24.27 | +36:57:35.0 | HIP 25225 | 24.46 |
| 2026-09-30 12:00 | 05:25:35.87 | +37:00:02.6 | HIP 25225 | 25.20 |
| 2026-10-01 00:00 | 05:25:47.14 | +37:02:30.0 | HIP 25292 | 24.67 |
| 2026-10-01 12:00 | 05:25:58.05 | +37:04:57.4 | HIP 25292 | 24.01 |
| 2026-10-02 00:00 | 05:26:08.61 | +37:07:24.6 | HIP 25292 | 23.75 |
| 2026-10-02 12:00 | 05:26:18.82 | +37:09:51.7 | HIP 25605 | 23.36 |
| 2026-10-03 00:00 | 05:26:28.68 | +37:12:18.6 | HIP 25605 | 21.11 |
| 2026-10-03 12:00 | 05:26:38.18 | +37:14:45.4 | HIP 25605 | 19.19 |
| 2026-10-04 00:00 | 05:26:47.32 | +37:17:12.1 | HIP 25605 | 17.67 |
| 2026-10-04 12:00 | 05:26:56.10 | +37:19:38.6 | HIP 25605 | 16.66 |
| 2026-10-05 00:00 | 05:27:04.52 | +37:22:04.9 | HIP 25605 | 16.20 |
| 2026-10-05 12:00 | 05:27:12.57 | +37:24:31.0 | HIP 25605 | 16.34 |
| 2026-10-06 00:00 | 05:27:20.26 | +37:26:56.9 | HIP 25605 | 17.02 |
| 2026-10-06 12:00 | 05:27:27.57 | +37:29:22.7 | HIP 25605 | 18.18 |
| 2026-10-07 00:00 | 05:27:34.52 | +37:31:48.2 | HIP 25605 | 19.70 |
| 2026-10-07 12:00 | 05:27:41.10 | +37:34:13.5 | HIP 25605 | 21.50 |
| 2026-10-08 00:00 | 05:27:47.30 | +37:36:38.6 | HIP 25605 | 23.50 |
| 2026-10-08 12:00 | 05:27:53.13 | +37:39:03.4 | HIP 25605 | 25.64 |
| 2026-10-09 00:00 | 05:27:58.58 | +37:41:28.0 | HIP 25605 | 27.88 |
| 2026-10-09 12:00 | 05:28:03.65 | +37:43:52.3 | HIP 25605 | 30.18 |
| 2026-10-10 00:00 | 05:28:08.34 | +37:46:16.4 | HIP 25817 | 31.77 |
| 2026-10-10 12:00 | 05:28:12.65 | +37:48:40.2 | HIP 25817 | 30.81 |
| 2026-10-11 00:00 | 05:28:16.58 | +37:51:03.6 | HIP 25817 | 30.12 |