| 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) |
| 2026-06-01 00:00 |
23:09:21.27 |
-00:14:27.0 |
HIP 114260 |
20.77 |
| 2026-06-01 12:00 |
23:09:25.89 |
-00:13:38.1 |
HIP 114260 |
22.15 |
| 2026-06-02 00:00 |
23:09:30.41 |
-00:12:49.7 |
HIP 114260 |
23.51 |
| 2026-06-02 12:00 |
23:09:34.83 |
-00:12:01.9 |
HIP 114260 |
24.85 |
| 2026-06-03 00:00 |
23:09:39.15 |
-00:11:14.6 |
HIP 114260 |
26.17 |
| 2026-06-03 12:00 |
23:09:43.37 |
-00:10:27.9 |
HIP 114260 |
27.46 |
| 2026-06-04 00:00 |
23:09:47.50 |
-00:09:41.8 |
HIP 114260 |
28.73 |
| 2026-06-04 12:00 |
23:09:51.52 |
-00:08:56.3 |
HIP 114260 |
29.98 |
| 2026-06-05 00:00 |
23:09:55.44 |
-00:08:11.3 |
HIP 114260 |
31.21 |
| 2026-06-05 12:00 |
23:09:59.27 |
-00:07:27.0 |
HIP 114260 |
32.41 |
| 2026-06-06 00:00 |
23:10:02.99 |
-00:06:43.2 |
HIP 114521 |
32.57 |
| 2026-06-06 12:00 |
23:10:06.61 |
-00:06:00.0 |
HIP 114521 |
31.41 |
| 2026-06-07 00:00 |
23:10:10.13 |
-00:05:17.3 |
HIP 114521 |
30.28 |
| 2026-06-07 12:00 |
23:10:13.55 |
-00:04:35.3 |
HIP 114521 |
29.18 |
| 2026-06-08 00:00 |
23:10:16.86 |
-00:03:53.9 |
HIP 114521 |
28.10 |
| 2026-06-08 12:00 |
23:10:20.07 |
-00:03:13.1 |
HIP 114521 |
27.05 |
| 2026-06-09 00:00 |
23:10:23.18 |
-00:02:32.9 |
HIP 114521 |
26.02 |
| 2026-06-09 12:00 |
23:10:26.19 |
-00:01:53.3 |
HIP 114521 |
25.02 |
| 2026-06-10 00:00 |
23:10:29.09 |
-00:01:14.3 |
HIP 114521 |
24.05 |
| 2026-06-10 12:00 |
23:10:31.89 |
-00:00:36.0 |
HIP 114521 |
23.11 |
| 2026-06-11 00:00 |
23:10:34.58 |
+00:00:01.8 |
HIP 114521 |
22.19 |
| 2026-06-11 12:00 |
23:10:37.17 |
+00:00:38.9 |
HIP 114521 |
21.30 |
| 2026-06-12 00:00 |
23:10:39.65 |
+00:01:15.4 |
HIP 114521 |
20.44 |
| 2026-06-12 12:00 |
23:10:42.03 |
+00:01:51.2 |
HIP 114521 |
19.61 |
| 2026-06-13 00:00 |
23:10:44.30 |
+00:02:26.4 |
HIP 114521 |
18.81 |
| 2026-06-13 12:00 |
23:10:46.46 |
+00:03:01.0 |
HIP 114521 |
18.03 |
| 2026-06-14 00:00 |
23:10:48.52 |
+00:03:34.9 |
HIP 114521 |
17.29 |
| 2026-06-14 12:00 |
23:10:50.47 |
+00:04:08.2 |
HIP 114521 |
16.57 |
| 2026-06-15 00:00 |
23:10:52.32 |
+00:04:40.9 |
HIP 114521 |
15.88 |
| 2026-06-15 12:00 |
23:10:54.05 |
+00:05:12.9 |
HIP 114521 |
15.23 |
| 2026-06-16 00:00 |
23:10:55.68 |
+00:05:44.2 |
HIP 114521 |
14.61 |
| 2026-06-16 12:00 |
23:10:57.21 |
+00:06:14.9 |
HIP 114521 |
14.02 |
| 2026-06-17 00:00 |
23:10:58.62 |
+00:06:44.9 |
HIP 114521 |
13.46 |
| 2026-06-17 12:00 |
23:10:59.93 |
+00:07:14.2 |
HIP 114521 |
12.94 |
| 2026-06-18 00:00 |
23:11:01.13 |
+00:07:42.9 |
HIP 114521 |
12.45 |
| 2026-06-18 12:00 |
23:11:02.22 |
+00:08:11.0 |
HIP 114521 |
12.00 |
| 2026-06-19 00:00 |
23:11:03.20 |
+00:08:38.3 |
HIP 114521 |
11.58 |
| 2026-06-19 12:00 |
23:11:04.07 |
+00:09:05.0 |
HIP 114521 |
11.20 |
| 2026-06-20 00:00 |
23:11:04.84 |
+00:09:31.0 |
HIP 114521 |
10.86 |
| 2026-06-20 12:00 |
23:11:05.49 |
+00:09:56.4 |
HIP 114521 |
10.56 |
| 2026-06-21 00:00 |
23:11:06.04 |
+00:10:21.0 |
HIP 114521 |
10.31 |
| 2026-06-21 12:00 |
23:11:06.48 |
+00:10:45.0 |
HIP 114521 |
10.09 |
| 2026-06-22 00:00 |
23:11:06.81 |
+00:11:08.3 |
HIP 114521 |
9.91 |