| Parameter |
Value |
| Designation |
218P/LINEAR |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2015-04-23T12:22:13.497600Z |
| Orbit solution date (soln_date, UTC) |
2026-05-11T09:35:38Z |
| Obs used |
517 |
| NEO |
Yes |
| M1 |
15.500 |
| K1 |
13.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-10-09.0000000 |
| e |
0.62196566 |
| q (au) |
1.170562 |
| a (au) |
3.096443 |
| i (deg) |
2.725398 |
| Ω (om, deg) |
176.027605 |
| ω (w, deg) |
59.673629 |
| M (ma, deg) |
162.705828 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.959 + 3.776\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.959 |
| n |
3.776 |
| gf |
0.949 |
| gb |
-1.000 |
| k |
0.987 |
| δ90 |
7.775 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
22:42:45.88 |
-05:37:04.7 |
HIP 112095 |
9.94 |
| 2026-05-12 12:00 |
22:43:47.47 |
-05:31:04.3 |
HIP 112095 |
25.92 |
| 2026-05-13 00:00 |
22:44:48.63 |
-05:25:06.0 |
HIP 112309 |
30.19 |
| 2026-05-13 12:00 |
22:45:49.34 |
-05:19:09.8 |
HIP 112309 |
27.81 |
| 2026-05-14 00:00 |
22:46:49.61 |
-05:13:15.6 |
HIP 112309 |
34.03 |
| 2026-05-14 12:00 |
22:47:49.44 |
-05:07:23.6 |
HIP 112621 |
30.21 |
| 2026-05-15 00:00 |
22:48:48.82 |
-05:01:33.8 |
HIP 112617 |
27.41 |
| 2026-05-15 12:00 |
22:49:47.76 |
-04:55:46.1 |
HIP 112617 |
28.63 |
| 2026-05-16 00:00 |
22:50:46.26 |
-04:50:00.7 |
HIP 112617 |
37.16 |
| 2026-05-16 12:00 |
22:51:44.32 |
-04:44:17.4 |
HIP 113056 |
30.25 |
| 2026-05-17 00:00 |
22:52:41.94 |
-04:38:36.4 |
HIP 113056 |
15.52 |
| 2026-05-17 12:00 |
22:53:39.11 |
-04:32:57.6 |
HIP 113056 |
6.60 |
| 2026-05-18 00:00 |
22:54:35.84 |
-04:27:21.1 |
HIP 113091 |
6.43 |
| 2026-05-18 12:00 |
22:55:32.13 |
-04:21:46.9 |
HIP 113091 |
20.76 |
| 2026-05-19 00:00 |
22:56:27.98 |
-04:16:15.0 |
HIP 113440 |
33.51 |
| 2026-05-19 12:00 |
22:57:23.39 |
-04:10:45.5 |
HIP 113440 |
25.57 |
| 2026-05-20 00:00 |
22:58:18.35 |
-04:05:18.2 |
HIP 113440 |
25.00 |
| 2026-05-20 12:00 |
22:59:12.88 |
-03:59:53.3 |
HIP 113537 |
23.08 |
| 2026-05-21 00:00 |
23:00:06.97 |
-03:54:30.8 |
HIP 113718 |
26.28 |
| 2026-05-21 12:00 |
23:01:00.62 |
-03:49:10.6 |
HIP 113718 |
12.76 |
| 2026-05-22 00:00 |
23:01:53.83 |
-03:43:52.9 |
HIP 113718 |
7.04 |
| 2026-05-22 12:00 |
23:02:46.60 |
-03:38:37.5 |
HIP 113740 |
16.03 |
| 2026-05-23 00:00 |
23:03:38.93 |
-03:33:24.6 |
HIP 113956 |
15.41 |
| 2026-05-23 12:00 |
23:04:30.83 |
-03:28:14.1 |
HIP 113956 |
2.46 |
| 2026-05-24 00:00 |
23:05:22.29 |
-03:23:06.0 |
HIP 113956 |
12.68 |
| 2026-05-24 12:00 |
23:06:13.31 |
-03:18:00.4 |
HIP 113956 |
26.30 |
| 2026-05-25 00:00 |
23:07:03.89 |
-03:12:57.3 |
HIP 113956 |
39.87 |
| 2026-05-25 12:00 |
23:07:54.04 |
-03:07:56.6 |
HIP 114313 |
39.03 |
| 2026-05-26 00:00 |
23:08:43.75 |
-03:02:58.4 |
HIP 114313 |
30.36 |
| 2026-05-26 12:00 |
23:09:33.02 |
-02:58:02.7 |
HIP 114313 |
26.05 |
| 2026-05-27 00:00 |
23:10:21.86 |
-02:53:09.6 |
HIP 114510 |
22.79 |
| 2026-05-27 12:00 |
23:11:10.26 |
-02:48:18.9 |
HIP 114510 |
18.95 |
| 2026-05-28 00:00 |
23:11:58.22 |
-02:43:30.9 |
HIP 114510 |
23.13 |
| 2026-05-28 12:00 |
23:12:45.75 |
-02:38:45.3 |
HIP 114700 |
20.15 |
| 2026-05-29 00:00 |
23:13:32.84 |
-02:34:02.3 |
HIP 114700 |
9.31 |
| 2026-05-29 12:00 |
23:14:19.49 |
-02:29:21.9 |
HIP 114700 |
9.32 |
| 2026-05-30 00:00 |
23:15:05.70 |
-02:24:44.1 |
HIP 114700 |
19.95 |
| 2026-05-30 12:00 |
23:15:51.48 |
-02:20:08.9 |
HIP 114700 |
31.80 |
| 2026-05-31 00:00 |
23:16:36.82 |
-02:15:36.3 |
HIP 115074 |
35.18 |
| 2026-05-31 12:00 |
23:17:21.71 |
-02:11:06.3 |
HIP 115074 |
23.81 |
| 2026-06-01 00:00 |
23:18:06.17 |
-02:06:39.0 |
HIP 115091 |
13.80 |
| 2026-06-01 12:00 |
23:18:50.19 |
-02:02:14.4 |
HIP 115091 |
7.26 |
| 2026-06-02 00:00 |
23:19:33.77 |
-01:57:52.4 |
HIP 115091 |
13.89 |