285P/LINEAR
Metadata
| Parameter | Value |
|---|---|
| Designation | 285P/LINEAR |
| Type | P |
| Perihelion (tp_cal, UTC) | 2023-01-12T20:28:47.072640Z |
| Orbit solution date (soln_date, UTC) | 2024-06-06T23:12:48Z |
| Obs used | 933 |
| NEO | - |
| M1 | 13.600 |
| K1 | 4.500 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2020-02-29.0000000 |
| e | 0.61787770 |
| q (au) | 1.723017 |
| a (au) | 4.509072 |
| i (deg) | 25.023386 |
| Ω (om, deg) | 185.483345 |
| ω (w, deg) | 178.401291 |
| M (ma, deg) | 252.033734 |
Magnitude
Scatter + Global Linear
$$ M_a = (15.549 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 15.549 |
| n | 2.000 |
| gf | 1.000 |
| gb | -1.000 |
| k | 0.800 |
| 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 |
|---|---|---|---|
| 2022-06-28 | 2022-08-13 | +85.0046 | -30.978 |
| 2022-08-13 | 2023-01-09 | -1.4071 | +0.571 |
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 | 11:26:09.22 | -02:03:35.0 | HIP 55713 | 19.96 |
| 2026-09-20 12:00 | 11:26:26.14 | -02:05:02.5 | HIP 55713 | 23.27 |
| 2026-09-21 00:00 | 11:26:43.05 | -02:06:30.1 | HIP 55713 | 26.92 |
| 2026-09-21 12:00 | 11:26:59.95 | -02:07:57.7 | HIP 55961 | 25.86 |
| 2026-09-22 00:00 | 11:27:16.83 | -02:09:25.5 | HIP 55961 | 22.24 |
| 2026-09-22 12:00 | 11:27:33.70 | -02:10:53.3 | HIP 55961 | 18.99 |
| 2026-09-23 00:00 | 11:27:50.55 | -02:12:21.1 | HIP 55961 | 16.31 |
| 2026-09-23 12:00 | 11:28:07.39 | -02:13:49.1 | HIP 55961 | 14.53 |
| 2026-09-24 00:00 | 11:28:24.21 | -02:15:17.1 | HIP 55961 | 14.00 |
| 2026-09-24 12:00 | 11:28:41.01 | -02:16:45.2 | HIP 55961 | 14.84 |
| 2026-09-25 00:00 | 11:28:57.80 | -02:18:13.3 | HIP 55961 | 16.85 |
| 2026-09-25 12:00 | 11:29:14.57 | -02:19:41.5 | HIP 55961 | 19.67 |
| 2026-09-26 00:00 | 11:29:31.32 | -02:21:09.7 | HIP 55961 | 23.00 |
| 2026-09-26 12:00 | 11:29:48.06 | -02:22:38.0 | HIP 55961 | 26.65 |
| 2026-09-27 00:00 | 11:30:04.77 | -02:24:06.3 | HIP 55961 | 30.51 |
| 2026-09-27 12:00 | 11:30:21.47 | -02:25:34.7 | HIP 56187 | 33.35 |
| 2026-09-28 00:00 | 11:30:38.15 | -02:27:03.1 | HIP 56187 | 30.87 |
| 2026-09-28 12:00 | 11:30:54.80 | -02:28:31.5 | HIP 56187 | 28.85 |
| 2026-09-29 00:00 | 11:31:11.44 | -02:30:00.0 | HIP 56187 | 27.39 |
| 2026-09-29 12:00 | 11:31:28.05 | -02:31:28.4 | HIP 56187 | 26.60 |
| 2026-09-30 00:00 | 11:31:44.65 | -02:32:56.9 | HIP 56187 | 26.52 |
| 2026-09-30 12:00 | 11:32:01.21 | -02:34:25.4 | HIP 56187 | 27.15 |
| 2026-10-01 00:00 | 11:32:17.76 | -02:35:53.9 | HIP 56187 | 28.46 |
| 2026-10-01 12:00 | 11:32:34.28 | -02:37:22.4 | HIP 56187 | 30.34 |
| 2026-10-02 00:00 | 11:32:50.78 | -02:38:50.9 | HIP 56482 | 30.61 |
| 2026-10-02 12:00 | 11:33:07.26 | -02:40:19.4 | HIP 56482 | 27.28 |
| 2026-10-03 00:00 | 11:33:23.71 | -02:41:47.9 | HIP 56482 | 24.28 |
| 2026-10-03 12:00 | 11:33:40.13 | -02:43:16.4 | HIP 56482 | 21.76 |
| 2026-10-04 00:00 | 11:33:56.53 | -02:44:44.9 | HIP 56482 | 19.88 |
| 2026-10-04 12:00 | 11:34:12.90 | -02:46:13.3 | HIP 56482 | 18.85 |
| 2026-10-05 00:00 | 11:34:29.24 | -02:47:41.7 | HIP 56482 | 18.79 |
| 2026-10-05 12:00 | 11:34:45.55 | -02:49:10.1 | HIP 56482 | 19.71 |
| 2026-10-06 00:00 | 11:35:01.84 | -02:50:38.5 | HIP 56482 | 21.48 |
| 2026-10-06 12:00 | 11:35:18.09 | -02:52:06.8 | HIP 56482 | 23.91 |
| 2026-10-07 00:00 | 11:35:34.32 | -02:53:35.1 | HIP 56482 | 26.81 |
| 2026-10-07 12:00 | 11:35:50.51 | -02:55:03.3 | HIP 56689 | 23.79 |
| 2026-10-08 00:00 | 11:36:06.67 | -02:56:31.4 | HIP 56689 | 19.93 |
| 2026-10-08 12:00 | 11:36:22.80 | -02:57:59.5 | HIP 56689 | 16.30 |
| 2026-10-09 00:00 | 11:36:38.90 | -02:59:27.6 | HIP 56689 | 13.08 |
| 2026-10-09 12:00 | 11:36:54.96 | -03:00:55.5 | HIP 56689 | 10.64 |
| 2026-10-10 00:00 | 11:37:10.99 | -03:02:23.4 | HIP 56689 | 9.58 |
| 2026-10-10 12:00 | 11:37:26.98 | -03:03:51.2 | HIP 56689 | 10.33 |
| 2026-10-11 00:00 | 11:37:42.94 | -03:05:18.9 | HIP 56689 | 12.56 |