88P/Howell
Metadata
| Parameter | Value |
|---|---|
| Designation | 88P/Howell |
| Type | P |
| Perihelion (tp_cal, UTC) | 2020-09-26T15:31:28.669440Z |
| Orbit solution date (soln_date, UTC) | 2026-05-06T05:41:46Z |
| Obs used | 3068 |
| NEO | - |
| M1 | 11.900 |
| K1 | 9.500 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2019-05-11.0000000 |
| e | 0.56412482 |
| q (au) | 1.353781 |
| a (au) | 3.105892 |
| i (deg) | 4.383759 |
| Ω (om, deg) | 56.693152 |
| ω (w, deg) | 235.884494 |
| M (ma, deg) | 269.131760 |
Magnitude
Scatter + Global Linear
$$ M_a = (7.355 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 7.355 |
| n | 6.000 |
| gf | 1.000 |
| gb | -1.000 |
| 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 |
|---|---|---|---|
| 2023-11-23 | 2025-05-02 | +5.9376 | -2.132 |
| 2025-05-02 | 2026-05-16 | +0.1529 | +0.374 |
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) |
|---|---|---|---|---|
| 2026-05-12 00:00 | 00:15:55.19 | -01:53:04.0 | HIP 1365 | 22.40 |
| 2026-05-12 12:00 | 00:17:12.92 | -01:44:51.3 | HIP 1365 | 5.96 |
| 2026-05-13 00:00 | 00:18:30.41 | -01:36:40.1 | HIP 1424 | 18.39 |
| 2026-05-13 12:00 | 00:19:47.67 | -01:28:30.3 | HIP 1424 | 37.81 |
| 2026-05-14 00:00 | 00:21:04.69 | -01:20:22.1 | HIP 1663 | 28.35 |
| 2026-05-14 12:00 | 00:22:21.48 | -01:12:15.5 | HIP 1843 | 25.66 |
| 2026-05-15 00:00 | 00:23:38.03 | -01:04:10.4 | HIP 1927 | 14.43 |
| 2026-05-15 12:00 | 00:24:54.35 | -00:56:06.9 | HIP 1927 | 20.44 |
| 2026-05-16 00:00 | 00:26:10.43 | -00:48:05.0 | HIP 2121 | 13.15 |
| 2026-05-16 12:00 | 00:27:26.28 | -00:40:04.7 | HIP 2121 | 17.75 |
| 2026-05-17 00:00 | 00:28:41.89 | -00:32:06.1 | HIP 2333 | 21.52 |
| 2026-05-17 12:00 | 00:29:57.27 | -00:24:09.1 | HIP 2333 | 5.15 |
| 2026-05-18 00:00 | 00:31:12.41 | -00:16:13.8 | HIP 2333 | 20.59 |
| 2026-05-18 12:00 | 00:32:27.32 | -00:08:20.2 | HIP 2585 | 19.22 |
| 2026-05-19 00:00 | 00:33:42.00 | -00:00:28.4 | HIP 2585 | 29.36 |
| 2026-05-19 12:00 | 00:34:56.44 | +00:07:21.8 | HIP 2787 | 38.77 |
| 2026-05-20 00:00 | 00:36:10.65 | +00:15:10.2 | HIP 2982 | 28.85 |
| 2026-05-20 12:00 | 00:37:24.62 | +00:22:56.8 | HIP 2982 | 8.79 |
| 2026-05-21 00:00 | 00:38:38.36 | +00:30:41.7 | HIP 2982 | 11.21 |
| 2026-05-21 12:00 | 00:39:51.87 | +00:38:24.7 | HIP 3055 | 24.32 |
| 2026-05-22 00:00 | 00:41:05.14 | +00:46:06.0 | HIP 3296 | 20.94 |
| 2026-05-22 12:00 | 00:42:18.18 | +00:53:45.5 | HIP 3296 | 8.63 |
| 2026-05-23 00:00 | 00:43:30.99 | +01:01:23.1 | HIP 3355 | 20.99 |
| 2026-05-23 12:00 | 00:44:43.56 | +01:08:58.9 | HIP 3481 | 37.71 |
| 2026-05-24 00:00 | 00:45:55.91 | +01:16:32.8 | HIP 3655 | 20.62 |
| 2026-05-24 12:00 | 00:47:08.02 | +01:24:04.9 | HIP 3655 | 9.98 |
| 2026-05-25 00:00 | 00:48:19.91 | +01:31:35.2 | HIP 3655 | 23.12 |
| 2026-05-25 12:00 | 00:49:31.56 | +01:39:03.5 | HIP 3793 | 40.05 |
| 2026-05-26 00:00 | 00:50:42.98 | +01:46:30.0 | HIP 4203 | 44.65 |
| 2026-05-26 12:00 | 00:51:54.17 | +01:53:54.5 | HIP 4203 | 26.14 |
| 2026-05-27 00:00 | 00:53:05.14 | +02:01:17.2 | HIP 4203 | 10.75 |
| 2026-05-27 12:00 | 00:54:15.87 | +02:08:37.9 | HIP 4203 | 16.84 |
| 2026-05-28 00:00 | 00:55:26.38 | +02:15:56.7 | HIP 4286 | 21.20 |
| 2026-05-28 12:00 | 00:56:36.65 | +02:23:13.6 | HIP 4529 | 21.43 |
| 2026-05-29 00:00 | 00:57:46.70 | +02:30:28.5 | HIP 4529 | 3.35 |
| 2026-05-29 12:00 | 00:58:56.52 | +02:37:41.4 | HIP 4564 | 8.38 |
| 2026-05-30 00:00 | 01:00:06.11 | +02:44:52.5 | HIP 4677 | 6.90 |
| 2026-05-30 12:00 | 01:01:15.47 | +02:52:01.5 | HIP 4738 | 18.06 |
| 2026-05-31 00:00 | 01:02:24.61 | +02:59:08.5 | HIP 4945 | 22.29 |
| 2026-05-31 12:00 | 01:03:33.52 | +03:06:13.6 | HIP 4945 | 9.30 |
| 2026-06-01 00:00 | 01:04:42.20 | +03:13:16.7 | HIP 4945 | 19.14 |
| 2026-06-01 12:00 | 01:05:50.65 | +03:20:17.7 | HIP 5166 | 5.36 |
| 2026-06-02 00:00 | 01:06:58.88 | +03:27:16.8 | HIP 5166 | 17.10 |