| Parameter |
Value |
| Designation |
C/2018 K1 (Weiland) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-04-06T21:34:06.764160Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:43Z |
| Obs used |
163 |
| NEO |
- |
| M1 |
12.500 |
| K1 |
14.750 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-05-25T13:00:23.616000Z |
| Discovery magnitude (MPC) |
17.30 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-06-04.0000000 |
| e |
0.93721411 |
| q (au) |
1.879169 |
| a (au) |
29.929796 |
| i (deg) |
164.192707 |
| Ω (om, deg) |
260.001799 |
| ω (w, deg) |
325.002910 |
| M (ma, deg) |
0.349731 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.352 + 5.304\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.352 |
| n |
5.304 |
| gf |
1.000 |
| gb |
-0.785 |
| k |
0.997 |
| δ90 |
10.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
09:55:08.64 |
+27:38:55.5 |
HIP 48541 |
15.63 |
| 2026-06-01 12:00 |
09:55:09.52 |
+27:38:27.9 |
HIP 48541 |
15.91 |
| 2026-06-02 00:00 |
09:55:10.46 |
+27:38:00.1 |
HIP 48541 |
16.22 |
| 2026-06-02 12:00 |
09:55:11.45 |
+27:37:32.1 |
HIP 48541 |
16.54 |
| 2026-06-03 00:00 |
09:55:12.48 |
+27:37:04.0 |
HIP 48541 |
16.89 |
| 2026-06-03 12:00 |
09:55:13.57 |
+27:36:35.8 |
HIP 48605 |
16.76 |
| 2026-06-04 00:00 |
09:55:14.71 |
+27:36:07.4 |
HIP 48605 |
16.43 |
| 2026-06-04 12:00 |
09:55:15.90 |
+27:35:38.8 |
HIP 48605 |
16.12 |
| 2026-06-05 00:00 |
09:55:17.13 |
+27:35:10.1 |
HIP 48605 |
15.82 |
| 2026-06-05 12:00 |
09:55:18.42 |
+27:34:41.2 |
HIP 48605 |
15.53 |
| 2026-06-06 00:00 |
09:55:19.76 |
+27:34:12.2 |
HIP 48605 |
15.26 |
| 2026-06-06 12:00 |
09:55:21.14 |
+27:33:43.0 |
HIP 48605 |
15.02 |
| 2026-06-07 00:00 |
09:55:22.58 |
+27:33:13.7 |
HIP 48605 |
14.80 |
| 2026-06-07 12:00 |
09:55:24.06 |
+27:32:44.2 |
HIP 48605 |
14.60 |
| 2026-06-08 00:00 |
09:55:25.59 |
+27:32:14.6 |
HIP 48605 |
14.43 |
| 2026-06-08 12:00 |
09:55:27.17 |
+27:31:44.9 |
HIP 48605 |
14.29 |
| 2026-06-09 00:00 |
09:55:28.80 |
+27:31:15.0 |
HIP 48605 |
14.17 |
| 2026-06-09 12:00 |
09:55:30.47 |
+27:30:45.0 |
HIP 48605 |
14.09 |
| 2026-06-10 00:00 |
09:55:32.20 |
+27:30:14.8 |
HIP 48605 |
14.05 |
| 2026-06-10 12:00 |
09:55:33.97 |
+27:29:44.6 |
HIP 48605 |
14.04 |
| 2026-06-11 00:00 |
09:55:35.79 |
+27:29:14.2 |
HIP 48605 |
14.06 |
| 2026-06-11 12:00 |
09:55:37.65 |
+27:28:43.6 |
HIP 48605 |
14.13 |
| 2026-06-12 00:00 |
09:55:39.56 |
+27:28:13.0 |
HIP 48605 |
14.23 |
| 2026-06-12 12:00 |
09:55:41.52 |
+27:27:42.2 |
HIP 48605 |
14.37 |
| 2026-06-13 00:00 |
09:55:43.53 |
+27:27:11.3 |
HIP 48605 |
14.55 |
| 2026-06-13 12:00 |
09:55:45.58 |
+27:26:40.3 |
HIP 48605 |
14.76 |
| 2026-06-14 00:00 |
09:55:47.67 |
+27:26:09.2 |
HIP 48605 |
15.02 |
| 2026-06-14 12:00 |
09:55:49.81 |
+27:25:37.9 |
HIP 48605 |
15.31 |
| 2026-06-15 00:00 |
09:55:52.00 |
+27:25:06.6 |
HIP 48605 |
15.64 |
| 2026-06-15 12:00 |
09:55:54.23 |
+27:24:35.1 |
HIP 48605 |
16.00 |
| 2026-06-16 00:00 |
09:55:56.51 |
+27:24:03.5 |
HIP 48605 |
16.39 |
| 2026-06-16 12:00 |
09:55:58.83 |
+27:23:31.9 |
HIP 48605 |
16.82 |
| 2026-06-17 00:00 |
09:56:01.20 |
+27:23:00.1 |
HIP 48605 |
17.27 |
| 2026-06-17 12:00 |
09:56:03.61 |
+27:22:28.2 |
HIP 48605 |
17.76 |
| 2026-06-18 00:00 |
09:56:06.06 |
+27:21:56.3 |
HIP 48605 |
18.28 |
| 2026-06-18 12:00 |
09:56:08.56 |
+27:21:24.2 |
HIP 48605 |
18.82 |
| 2026-06-19 00:00 |
09:56:11.10 |
+27:20:52.1 |
HIP 48605 |
19.38 |
| 2026-06-19 12:00 |
09:56:13.68 |
+27:20:19.8 |
HIP 48605 |
19.97 |
| 2026-06-20 00:00 |
09:56:16.30 |
+27:19:47.5 |
HIP 48605 |
20.58 |
| 2026-06-20 12:00 |
09:56:18.97 |
+27:19:15.1 |
HIP 48605 |
21.22 |
| 2026-06-21 00:00 |
09:56:21.67 |
+27:18:42.6 |
HIP 48605 |
21.87 |
| 2026-06-21 12:00 |
09:56:24.42 |
+27:18:10.0 |
HIP 48605 |
22.55 |
| 2026-06-22 00:00 |
09:56:27.21 |
+27:17:37.4 |
HIP 48605 |
23.24 |