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) |
|---|---|---|---|---|
| 2026-02-03 00:00 | 11:07:18.82 | -05:51:09.6 | HIP 54340 | 16.83 |
| 2026-02-03 12:00 | 11:07:07.54 | -05:49:58.8 | HIP 54340 | 14.96 |
| 2026-02-04 00:00 | 11:06:56.15 | -05:48:47.0 | HIP 54340 | 13.50 |
| 2026-02-04 12:00 | 11:06:44.67 | -05:47:34.0 | HIP 54340 | 12.63 |
| 2026-02-05 00:00 | 11:06:33.09 | -05:46:20.0 | HIP 54340 | 12.48 |
| 2026-02-05 12:00 | 11:06:21.41 | -05:45:04.8 | HIP 54340 | 13.11 |
| 2026-02-06 00:00 | 11:06:09.64 | -05:43:48.6 | HIP 54340 | 14.43 |
| 2026-02-06 12:00 | 11:05:57.77 | -05:42:31.4 | HIP 54340 | 16.29 |
| 2026-02-07 00:00 | 11:05:45.81 | -05:41:13.0 | HIP 54340 | 18.54 |
| 2026-02-07 12:00 | 11:05:33.76 | -05:39:53.6 | HIP 54259 | 18.32 |
| 2026-02-08 00:00 | 11:05:21.62 | -05:38:33.1 | HIP 54259 | 18.49 |
| 2026-02-08 12:00 | 11:05:09.39 | -05:37:11.6 | HIP 54121 | 17.64 |
| 2026-02-09 00:00 | 11:04:57.08 | -05:35:49.1 | HIP 54121 | 14.73 |
| 2026-02-09 12:00 | 11:04:44.68 | -05:34:25.5 | HIP 54121 | 12.04 |
| 2026-02-10 00:00 | 11:04:32.20 | -05:33:00.9 | HIP 54121 | 9.78 |
| 2026-02-10 12:00 | 11:04:19.64 | -05:31:35.2 | HIP 54121 | 8.31 |
| 2026-02-11 00:00 | 11:04:07.00 | -05:30:08.5 | HIP 54121 | 8.14 |
| 2026-02-11 12:00 | 11:03:54.28 | -05:28:40.9 | HIP 54121 | 9.35 |
| 2026-02-12 00:00 | 11:03:41.49 | -05:27:12.2 | HIP 54121 | 11.54 |
| 2026-02-12 12:00 | 11:03:28.62 | -05:25:42.5 | HIP 54121 | 14.29 |
| 2026-02-13 00:00 | 11:03:15.68 | -05:24:11.9 | HIP 54121 | 17.34 |
| 2026-02-13 12:00 | 11:03:02.67 | -05:22:40.3 | HIP 54121 | 20.57 |
| 2026-02-14 00:00 | 11:02:49.59 | -05:21:07.7 | HIP 54072 | 21.71 |
| 2026-02-14 12:00 | 11:02:36.44 | -05:19:34.1 | HIP 54014 | 22.60 |
| 2026-02-15 00:00 | 11:02:23.23 | -05:17:59.6 | HIP 54014 | 22.21 |
| 2026-02-15 12:00 | 11:02:09.95 | -05:16:24.2 | HIP 54014 | 22.40 |
| 2026-02-16 00:00 | 11:01:56.62 | -05:14:47.8 | HIP 54014 | 23.18 |
| 2026-02-16 12:00 | 11:01:43.22 | -05:13:10.6 | HIP 54014 | 24.50 |
| 2026-02-17 00:00 | 11:01:29.77 | -05:11:32.4 | HIP 54014 | 26.28 |
| 2026-02-17 12:00 | 11:01:16.26 | -05:09:53.3 | HIP 54014 | 28.45 |
| 2026-02-18 00:00 | 11:01:02.70 | -05:08:13.3 | HIP 54014 | 30.93 |
| 2026-02-18 12:00 | 11:00:49.09 | -05:06:32.5 | HIP 54014 | 33.66 |
| 2026-02-19 00:00 | 11:00:35.43 | -05:04:50.8 | HIP 53672 | 35.07 |
| 2026-02-19 12:00 | 11:00:21.72 | -05:03:08.3 | HIP 53672 | 31.44 |
| 2026-02-20 00:00 | 11:00:07.96 | -05:01:24.9 | HIP 53672 | 27.84 |
| 2026-02-20 12:00 | 10:59:54.17 | -04:59:40.6 | HIP 53672 | 24.29 |
| 2026-02-21 00:00 | 10:59:40.33 | -04:57:55.6 | HIP 53672 | 20.84 |
| 2026-02-21 12:00 | 10:59:26.45 | -04:56:09.8 | HIP 53672 | 17.54 |
| 2026-02-22 00:00 | 10:59:12.54 | -04:54:23.2 | HIP 53672 | 14.51 |
| 2026-02-22 12:00 | 10:58:58.60 | -04:52:35.8 | HIP 53672 | 11.99 |
| 2026-02-23 00:00 | 10:58:44.62 | -04:50:47.6 | HIP 53672 | 10.35 |
| 2026-02-23 12:00 | 10:58:30.61 | -04:48:58.7 | HIP 53672 | 10.06 |
| 2026-02-24 00:00 | 10:58:16.57 | -04:47:09.0 | HIP 53582 | 9.16 |