P/2018 C1 (Lemmon-Read)
| 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) |
| 2026-02-03 00:00 |
22:22:54.56 |
-05:31:37.7 |
HIP 110359 |
36.41 |
| 2026-02-03 12:00 |
22:23:08.56 |
-05:30:20.1 |
HIP 110601 |
37.07 |
| 2026-02-04 00:00 |
22:23:22.60 |
-05:29:02.3 |
HIP 110601 |
36.54 |
| 2026-02-04 12:00 |
22:23:36.65 |
-05:27:44.1 |
HIP 110601 |
36.38 |
| 2026-02-05 00:00 |
22:23:50.73 |
-05:26:25.6 |
HIP 110578 |
36.43 |
| 2026-02-05 12:00 |
22:24:04.84 |
-05:25:06.8 |
HIP 110739 |
33.62 |
| 2026-02-06 00:00 |
22:24:18.97 |
-05:23:47.8 |
HIP 110739 |
29.88 |
| 2026-02-06 12:00 |
22:24:33.13 |
-05:22:28.4 |
HIP 110739 |
26.14 |
| 2026-02-07 00:00 |
22:24:47.30 |
-05:21:08.8 |
HIP 110739 |
22.39 |
| 2026-02-07 12:00 |
22:25:01.50 |
-05:19:48.8 |
HIP 110739 |
18.65 |
| 2026-02-08 00:00 |
22:25:15.72 |
-05:18:28.6 |
HIP 110739 |
14.92 |
| 2026-02-08 12:00 |
22:25:29.96 |
-05:17:08.1 |
HIP 110739 |
11.22 |
| 2026-02-09 00:00 |
22:25:44.22 |
-05:15:47.4 |
HIP 110739 |
7.60 |
| 2026-02-09 12:00 |
22:25:58.50 |
-05:14:26.3 |
HIP 110739 |
4.30 |
| 2026-02-10 00:00 |
22:26:12.80 |
-05:13:05.0 |
HIP 110739 |
2.84 |
| 2026-02-10 12:00 |
22:26:27.12 |
-05:11:43.5 |
HIP 110739 |
5.17 |
| 2026-02-11 00:00 |
22:26:41.46 |
-05:10:21.6 |
HIP 110739 |
8.64 |
| 2026-02-11 12:00 |
22:26:55.81 |
-05:08:59.5 |
HIP 110739 |
12.32 |
| 2026-02-12 00:00 |
22:27:10.19 |
-05:07:37.2 |
HIP 110739 |
16.07 |
| 2026-02-12 12:00 |
22:27:24.57 |
-05:06:14.6 |
HIP 110739 |
19.86 |
| 2026-02-13 00:00 |
22:27:38.98 |
-05:04:51.8 |
HIP 110920 |
17.90 |
| 2026-02-13 12:00 |
22:27:53.39 |
-05:03:28.7 |
HIP 110920 |
14.89 |
| 2026-02-14 00:00 |
22:28:07.83 |
-05:02:05.3 |
HIP 110920 |
12.35 |
| 2026-02-14 12:00 |
22:28:22.27 |
-05:00:41.8 |
HIP 110920 |
10.63 |
| 2026-02-15 00:00 |
22:28:36.73 |
-04:59:18.0 |
HIP 110920 |
10.16 |
| 2026-02-15 12:00 |
22:28:51.20 |
-04:57:53.9 |
HIP 110920 |
11.10 |
| 2026-02-16 00:00 |
22:29:05.68 |
-04:56:29.7 |
HIP 110920 |
13.16 |
| 2026-02-16 12:00 |
22:29:20.18 |
-04:55:05.2 |
HIP 110920 |
15.91 |
| 2026-02-17 00:00 |
22:29:34.68 |
-04:53:40.5 |
HIP 111102 |
14.03 |
| 2026-02-17 12:00 |
22:29:49.20 |
-04:52:15.6 |
HIP 111102 |
10.16 |
| 2026-02-18 00:00 |
22:30:03.72 |
-04:50:50.4 |
HIP 111102 |
6.28 |
| 2026-02-18 12:00 |
22:30:18.25 |
-04:49:25.1 |
HIP 111102 |
2.42 |
| 2026-02-19 00:00 |
22:30:32.79 |
-04:47:59.6 |
HIP 111102 |
1.60 |
| 2026-02-19 12:00 |
22:30:47.34 |
-04:46:33.8 |
HIP 111102 |
5.44 |
| 2026-02-20 00:00 |
22:31:01.89 |
-04:45:07.9 |
HIP 111102 |
9.33 |
| 2026-02-20 12:00 |
22:31:16.45 |
-04:43:41.8 |
HIP 111102 |
13.23 |
| 2026-02-21 00:00 |
22:31:31.02 |
-04:42:15.5 |
HIP 111102 |
17.13 |
| 2026-02-21 12:00 |
22:31:45.58 |
-04:40:49.0 |
HIP 111102 |
21.04 |
| 2026-02-22 00:00 |
22:32:00.16 |
-04:39:22.3 |
HIP 111102 |
24.94 |
| 2026-02-22 12:00 |
22:32:14.73 |
-04:37:55.5 |
HIP 111373 |
25.12 |
| 2026-02-23 00:00 |
22:32:29.31 |
-04:36:28.4 |
HIP 111373 |
21.21 |
| 2026-02-23 12:00 |
22:32:43.89 |
-04:35:01.2 |
HIP 111373 |
17.30 |
| 2026-02-24 00:00 |
22:32:58.48 |
-04:33:33.9 |
HIP 111373 |
13.39 |