217P/LINEAR
Metadata
| Parameter | Value |
|---|---|
| Designation | 217P/LINEAR |
| Type | P |
| Perihelion (tp_cal, UTC) | 2009-09-08T15:10:27.419520Z |
| Orbit solution date (soln_date, UTC) | 2026-04-30T15:30:22Z |
| Obs used | 3359 |
| NEO | Yes |
| M1 | 14.500 |
| K1 | 4.750 |
| PC | - |
Osculating Elements
| Parameter | Value |
|---|---|
| Epoch (epoch_cal, TDB) | 2013-01-14.0000000 |
| e | 0.68880769 |
| q (au) | 1.229097 |
| a (au) | 3.949637 |
| i (deg) | 12.861440 |
| Ω (om, deg) | 125.536330 |
| ω (w, deg) | 246.943590 |
| M (ma, deg) | 153.612051 |
Magnitude
Scatter + Global Linear
$$ M_a = (10.106 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$
Model Parameters
| Parameter | Value |
|---|---|
| H0 | 10.106 |
| n | 6.000 |
| gf | 0.801 |
| gb | -0.500 |
| k | 0.874 |
| δ90 | 1.000 |
| 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 |
|---|---|---|---|
| 2024-05-01 | 2025-05-24 | -12.8918 | +1.338 |
| 2025-05-24 | 2025-11-02 | +5.5608 | -1.282 |
| 2025-11-02 | 2025-12-19 | +2.7111 | -0.241 |
| 2025-12-19 | 2026-02-15 | -32.1958 | +14.706 |
| 2026-02-15 | 2026-04-06 | +19.1139 | -10.797 |
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 | 08:51:00.77 | +21:18:08.4 | HIP 43479 | 14.25 |
| 2026-06-01 12:00 | 08:51:28.68 | +21:16:35.2 | HIP 43479 | 11.85 |
| 2026-06-02 00:00 | 08:51:56.67 | +21:15:01.4 | HIP 43479 | 12.92 |
| 2026-06-02 12:00 | 08:52:24.71 | +21:13:27.0 | HIP 43479 | 16.85 |
| 2026-06-03 00:00 | 08:52:52.83 | +21:11:52.1 | HIP 43682 | 22.17 |
| 2026-06-03 12:00 | 08:53:21.01 | +21:10:16.7 | HIP 43682 | 17.12 |
| 2026-06-04 00:00 | 08:53:49.25 | +21:08:40.7 | HIP 43682 | 13.64 |
| 2026-06-04 12:00 | 08:54:17.56 | +21:07:04.2 | HIP 43682 | 13.07 |
| 2026-06-05 00:00 | 08:54:45.93 | +21:05:27.1 | HIP 43682 | 15.75 |
| 2026-06-05 12:00 | 08:55:14.36 | +21:03:49.5 | HIP 43682 | 20.47 |
| 2026-06-06 00:00 | 08:55:42.85 | +21:02:11.4 | HIP 43682 | 26.15 |
| 2026-06-06 12:00 | 08:56:11.41 | +21:00:32.7 | HIP 43985 | 26.93 |
| 2026-06-07 00:00 | 08:56:40.02 | +20:58:53.6 | HIP 43985 | 24.65 |
| 2026-06-07 12:00 | 08:57:08.69 | +20:57:13.9 | HIP 43985 | 24.17 |
| 2026-06-08 00:00 | 08:57:37.41 | +20:55:33.6 | HIP 44097 | 23.29 |
| 2026-06-08 12:00 | 08:58:06.20 | +20:53:52.9 | HIP 44097 | 19.83 |
| 2026-06-09 00:00 | 08:58:35.04 | +20:52:11.6 | HIP 44097 | 18.44 |
| 2026-06-09 12:00 | 08:59:03.93 | +20:50:29.9 | HIP 44072 | 18.70 |
| 2026-06-10 00:00 | 08:59:32.88 | +20:48:47.6 | HIP 44072 | 20.52 |
| 2026-06-10 12:00 | 09:00:01.88 | +20:47:04.8 | HIP 44072 | 24.29 |
| 2026-06-11 00:00 | 09:00:30.93 | +20:45:21.5 | HIP 44072 | 29.29 |
| 2026-06-11 12:00 | 09:01:00.04 | +20:43:37.7 | HIP 44072 | 34.99 |
| 2026-06-12 00:00 | 09:01:29.19 | +20:41:53.4 | HIP 44467 | 30.74 |
| 2026-06-12 12:00 | 09:01:58.40 | +20:40:08.6 | HIP 44467 | 23.70 |
| 2026-06-13 00:00 | 09:02:27.65 | +20:38:23.4 | HIP 44467 | 16.64 |
| 2026-06-13 12:00 | 09:02:56.95 | +20:36:37.6 | HIP 44467 | 9.59 |
| 2026-06-14 00:00 | 09:03:26.30 | +20:34:51.4 | HIP 44467 | 2.64 |
| 2026-06-14 12:00 | 09:03:55.70 | +20:33:04.7 | HIP 44467 | 4.77 |
| 2026-06-15 00:00 | 09:04:25.14 | +20:31:17.5 | HIP 44467 | 11.83 |
| 2026-06-15 12:00 | 09:04:54.62 | +20:29:29.8 | HIP 44467 | 18.95 |
| 2026-06-16 00:00 | 09:05:24.15 | +20:27:41.7 | HIP 44716 | 18.69 |
| 2026-06-16 12:00 | 09:05:53.72 | +20:25:53.1 | HIP 44716 | 12.47 |
| 2026-06-17 00:00 | 09:06:23.33 | +20:24:04.0 | HIP 44716 | 8.01 |
| 2026-06-17 12:00 | 09:06:52.98 | +20:22:14.5 | HIP 44716 | 8.70 |
| 2026-06-18 00:00 | 09:07:22.67 | +20:20:24.6 | HIP 44716 | 13.81 |
| 2026-06-18 12:00 | 09:07:52.40 | +20:18:34.2 | HIP 44716 | 20.24 |
| 2026-06-19 00:00 | 09:08:22.17 | +20:16:43.4 | HIP 44921 | 18.23 |
| 2026-06-19 12:00 | 09:08:51.97 | +20:14:52.1 | HIP 44921 | 13.83 |
| 2026-06-20 00:00 | 09:09:21.81 | +20:13:00.4 | HIP 44921 | 12.44 |
| 2026-06-20 12:00 | 09:09:51.68 | +20:11:08.3 | HIP 44921 | 14.94 |
| 2026-06-21 00:00 | 09:10:21.59 | +20:09:15.7 | HIP 44964 | 18.41 |
| 2026-06-21 12:00 | 09:10:51.52 | +20:07:22.8 | HIP 44964 | 22.01 |
| 2026-06-22 00:00 | 09:11:21.49 | +20:05:29.4 | HIP 45131 | 20.91 |