| Parameter |
Value |
| Designation |
P/2018 C1 (Lemmon-Read) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-02-25T13:35:25.753920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:40Z |
| Obs used |
121 |
| NEO |
- |
| M1 |
14.000 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-03-01.0000000 |
| e |
0.53445831 |
| q (au) |
2.595759 |
| a (au) |
5.575781 |
| i (deg) |
5.133510 |
| Ω (om, deg) |
270.449437 |
| ω (w, deg) |
234.329129 |
| M (ma, deg) |
0.257046 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.162 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.162 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.882 |
| k |
1.000 |
| δ90 |
9.994 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
22:47:15.29 |
-03:03:23.2 |
HIP 112550 |
15.67 |
| 2026-03-26 12:00 |
22:47:28.91 |
-03:01:52.5 |
HIP 112550 |
12.95 |
| 2026-03-27 00:00 |
22:47:42.50 |
-03:00:21.9 |
HIP 112550 |
10.84 |
| 2026-03-27 12:00 |
22:47:56.05 |
-02:58:51.3 |
HIP 112550 |
9.75 |
| 2026-03-28 00:00 |
22:48:09.57 |
-02:57:20.8 |
HIP 112550 |
9.99 |
| 2026-03-28 12:00 |
22:48:23.06 |
-02:55:50.4 |
HIP 112550 |
11.49 |
| 2026-03-29 00:00 |
22:48:36.51 |
-02:54:20.0 |
HIP 112550 |
13.82 |
| 2026-03-29 12:00 |
22:48:49.92 |
-02:52:49.8 |
HIP 112550 |
16.64 |
| 2026-03-30 00:00 |
22:49:03.30 |
-02:51:19.6 |
HIP 112742 |
13.36 |
| 2026-03-30 12:00 |
22:49:16.64 |
-02:49:49.5 |
HIP 112742 |
9.88 |
| 2026-03-31 00:00 |
22:49:29.94 |
-02:48:19.5 |
HIP 112742 |
6.62 |
| 2026-03-31 12:00 |
22:49:43.21 |
-02:46:49.6 |
HIP 112742 |
4.07 |
| 2026-04-01 00:00 |
22:49:56.43 |
-02:45:19.8 |
HIP 112742 |
3.97 |
| 2026-04-01 12:00 |
22:50:09.62 |
-02:43:50.1 |
HIP 112742 |
6.42 |
| 2026-04-02 00:00 |
22:50:22.77 |
-02:42:20.4 |
HIP 112742 |
9.62 |
| 2026-04-02 12:00 |
22:50:35.88 |
-02:40:50.9 |
HIP 112742 |
13.03 |
| 2026-04-03 00:00 |
22:50:48.95 |
-02:39:21.5 |
HIP 112742 |
16.51 |
| 2026-04-03 12:00 |
22:51:01.98 |
-02:37:52.3 |
HIP 112742 |
20.02 |
| 2026-04-04 00:00 |
22:51:14.96 |
-02:36:23.1 |
HIP 112967 |
21.28 |
| 2026-04-04 12:00 |
22:51:27.91 |
-02:34:54.1 |
HIP 112967 |
18.21 |
| 2026-04-05 00:00 |
22:51:40.81 |
-02:33:25.2 |
HIP 112967 |
15.36 |
| 2026-04-05 12:00 |
22:51:53.67 |
-02:31:56.4 |
HIP 112967 |
12.87 |
| 2026-04-06 00:00 |
22:52:06.49 |
-02:30:27.7 |
HIP 112967 |
10.97 |
| 2026-04-06 12:00 |
22:52:19.26 |
-02:28:59.2 |
HIP 112967 |
10.01 |
| 2026-04-07 00:00 |
22:52:31.99 |
-02:27:30.8 |
HIP 112967 |
10.24 |
| 2026-04-07 12:00 |
22:52:44.68 |
-02:26:02.6 |
HIP 112967 |
11.57 |
| 2026-04-08 00:00 |
22:52:57.31 |
-02:24:34.5 |
HIP 113037 |
10.81 |
| 2026-04-08 12:00 |
22:53:09.91 |
-02:23:06.5 |
HIP 113037 |
7.42 |
| 2026-04-09 00:00 |
22:53:22.45 |
-02:21:38.7 |
HIP 113037 |
4.18 |
| 2026-04-09 12:00 |
22:53:34.95 |
-02:20:11.1 |
HIP 113037 |
1.93 |
| 2026-04-10 00:00 |
22:53:47.40 |
-02:18:43.6 |
HIP 113037 |
3.70 |
| 2026-04-10 12:00 |
22:53:59.81 |
-02:17:16.3 |
HIP 113037 |
6.86 |
| 2026-04-11 00:00 |
22:54:12.16 |
-02:15:49.2 |
HIP 113037 |
10.18 |
| 2026-04-11 12:00 |
22:54:24.47 |
-02:14:22.2 |
HIP 113037 |
13.53 |
| 2026-04-12 00:00 |
22:54:36.72 |
-02:12:55.4 |
HIP 113037 |
16.89 |
| 2026-04-12 12:00 |
22:54:48.93 |
-02:11:28.8 |
HIP 113037 |
20.24 |
| 2026-04-13 00:00 |
22:55:01.08 |
-02:10:02.4 |
HIP 113037 |
23.59 |
| 2026-04-13 12:00 |
22:55:13.19 |
-02:08:36.2 |
HIP 113037 |
26.93 |
| 2026-04-14 00:00 |
22:55:25.24 |
-02:07:10.2 |
HIP 113037 |
30.25 |
| 2026-04-14 12:00 |
22:55:37.24 |
-02:05:44.3 |
HIP 113037 |
33.57 |
| 2026-04-15 00:00 |
22:55:49.18 |
-02:04:18.7 |
HIP 113037 |
36.87 |
| 2026-04-15 12:00 |
22:56:01.07 |
-02:02:53.3 |
HIP 113421 |
39.53 |
| 2026-04-16 00:00 |
22:56:12.91 |
-02:01:28.0 |
HIP 113421 |
37.87 |