88P/Howell
Metadata
| Parameter | Value |
|---|---|
| Designation | 88P/Howell |
| Type | P |
| Perihelion (tp_cal, UTC) | 2020-09-26T15:23:05.112960Z |
| Orbit solution date (soln_date, UTC) | 2026-05-28T12:50:59Z |
| Obs used | 3106 |
| NEO | - |
| M1 | 11.800 |
| K1 | 9.750 |
| PC | 0.030 |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2019-06-14.0000000 |
| e | 0.56414606 |
| q (au) | 1.353675 |
| a (au) | 3.105800 |
| i (deg) | 4.383765 |
| Ω (om, deg) | 56.691986 |
| ω (w, deg) | 235.888784 |
| M (ma, deg) | 275.251179 |
Magnitude
Scatter + Global Linear
$$ M_a = (7.300 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 7.300 |
| n | 6.000 |
| gf | 1.000 |
| gb | -0.624 |
| 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 | 2025-12-30 | +2.4250 | -1.559 |
| 2025-12-30 | 2025-01-26 | +5.4876 | -2.282 |
| 2025-01-26 | 2026-06-06 | -0.1631 | +0.914 |
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) |
|---|---|---|---|---|
| 2026-06-01 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 |
| 2026-06-02 12:00 | 01:08:06.88 | +03:34:13.8 | HIP 5230 | 23.44 |
| 2026-06-03 00:00 | 01:09:14.65 | +03:41:08.8 | HIP 5230 | 36.15 |
| 2026-06-03 12:00 | 01:10:22.19 | +03:48:01.8 | HIP 5572 | 30.21 |
| 2026-06-04 00:00 | 01:11:29.51 | +03:54:52.7 | HIP 5573 | 30.89 |
| 2026-06-04 12:00 | 01:12:36.59 | +04:01:41.6 | HIP 5629 | 24.50 |
| 2026-06-05 00:00 | 01:13:43.45 | +04:08:28.4 | HIP 5848 | 24.00 |
| 2026-06-05 12:00 | 01:14:50.08 | +04:15:13.2 | HIP 5828 | 20.63 |
| 2026-06-06 00:00 | 01:15:56.49 | +04:21:55.9 | HIP 6018 | 20.96 |
| 2026-06-06 12:00 | 01:17:02.66 | +04:28:36.5 | HIP 6018 | 6.73 |
| 2026-06-07 00:00 | 01:18:08.61 | +04:35:15.0 | HIP 6142 | 11.61 |
| 2026-06-07 12:00 | 01:19:14.32 | +04:41:51.4 | HIP 6142 | 6.07 |
| 2026-06-08 00:00 | 01:20:19.81 | +04:48:25.7 | HIP 6142 | 23.65 |
| 2026-06-08 12:00 | 01:21:25.07 | +04:54:57.9 | HIP 6441 | 22.26 |
| 2026-06-09 00:00 | 01:22:30.09 | +05:01:28.0 | HIP 6416 | 13.72 |
| 2026-06-09 12:00 | 01:23:34.89 | +05:07:55.9 | HIP 6525 | 11.35 |
| 2026-06-10 00:00 | 01:24:39.45 | +05:14:21.8 | HIP 6525 | 13.04 |
| 2026-06-10 12:00 | 01:25:43.78 | +05:20:45.5 | HIP 6638 | 10.90 |
| 2026-06-11 00:00 | 01:26:47.88 | +05:27:07.0 | HIP 6815 | 14.22 |
| 2026-06-11 12:00 | 01:27:51.75 | +05:33:26.4 | HIP 6815 | 12.61 |
| 2026-06-12 00:00 | 01:28:55.38 | +05:39:43.7 | HIP 6815 | 26.41 |
| 2026-06-12 12:00 | 01:29:58.78 | +05:45:58.7 | HIP 7046 | 17.83 |
| 2026-06-13 00:00 | 01:31:01.94 | +05:52:11.7 | HIP 7046 | 6.87 |
| 2026-06-13 12:00 | 01:32:04.86 | +05:58:22.4 | HIP 7046 | 18.57 |
| 2026-06-14 00:00 | 01:33:07.55 | +06:04:30.9 | HIP 7259 | 30.14 |
| 2026-06-14 12:00 | 01:34:10.00 | +06:10:37.3 | HIP 7259 | 25.14 |
| 2026-06-15 00:00 | 01:35:12.21 | +06:16:41.5 | HIP 7454 | 13.83 |
| 2026-06-15 12:00 | 01:36:14.18 | +06:22:43.5 | HIP 7454 | 2.98 |
| 2026-06-16 00:00 | 01:37:15.92 | +06:28:43.3 | HIP 7502 | 16.74 |
| 2026-06-16 12:00 | 01:38:17.41 | +06:34:40.9 | HIP 7502 | 25.31 |
| 2026-06-17 00:00 | 01:39:18.66 | +06:40:36.3 | HIP 7774 | 20.74 |
| 2026-06-17 12:00 | 01:40:19.66 | +06:46:29.5 | HIP 7803 | 18.73 |
| 2026-06-18 00:00 | 01:41:20.43 | +06:52:20.5 | HIP 7803 | 19.09 |
| 2026-06-18 12:00 | 01:42:20.95 | +06:58:09.3 | HIP 7803 | 29.97 |
| 2026-06-19 00:00 | 01:43:21.23 | +07:03:55.9 | HIP 8120 | 15.20 |
| 2026-06-19 12:00 | 01:44:21.27 | +07:09:40.2 | HIP 8120 | 4.99 |
| 2026-06-20 00:00 | 01:45:21.06 | +07:15:22.4 | HIP 8120 | 18.05 |
| 2026-06-20 12:00 | 01:46:20.60 | +07:21:02.4 | HIP 8319 | 26.32 |
| 2026-06-21 00:00 | 01:47:19.90 | +07:26:40.2 | HIP 8429 | 24.63 |
| 2026-06-21 12:00 | 01:48:18.96 | +07:32:15.8 | HIP 8429 | 10.29 |
| 2026-06-22 00:00 | 01:49:17.76 | +07:37:49.1 | HIP 8429 | 9.75 |