| 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) |
| 2026-07-29 00:00 |
10:01:25.67 |
+26:36:15.7 |
HIP 49186 |
19.73 |
| 2026-07-29 12:00 |
10:01:30.63 |
+26:35:43.2 |
HIP 49186 |
18.62 |
| 2026-07-30 00:00 |
10:01:35.61 |
+26:35:10.8 |
HIP 49186 |
17.53 |
| 2026-07-30 12:00 |
10:01:40.61 |
+26:34:38.6 |
HIP 49186 |
16.47 |
| 2026-07-31 00:00 |
10:01:45.62 |
+26:34:06.3 |
HIP 49186 |
15.42 |
| 2026-07-31 12:00 |
10:01:50.64 |
+26:33:34.2 |
HIP 49186 |
14.41 |
| 2026-08-01 00:00 |
10:01:55.69 |
+26:33:02.2 |
HIP 49186 |
13.44 |
| 2026-08-01 12:00 |
10:02:00.74 |
+26:32:30.2 |
HIP 49186 |
12.52 |
| 2026-08-02 00:00 |
10:02:05.81 |
+26:31:58.4 |
HIP 49186 |
11.65 |
| 2026-08-02 12:00 |
10:02:10.89 |
+26:31:26.6 |
HIP 49186 |
10.87 |
| 2026-08-03 00:00 |
10:02:15.99 |
+26:30:54.9 |
HIP 49186 |
10.18 |
| 2026-08-03 12:00 |
10:02:21.10 |
+26:30:23.4 |
HIP 49186 |
9.61 |
| 2026-08-04 00:00 |
10:02:26.23 |
+26:29:51.9 |
HIP 49186 |
9.18 |
| 2026-08-04 12:00 |
10:02:31.36 |
+26:29:20.5 |
HIP 49186 |
8.91 |
| 2026-08-05 00:00 |
10:02:36.51 |
+26:28:49.2 |
HIP 49186 |
8.82 |
| 2026-08-05 12:00 |
10:02:41.67 |
+26:28:18.0 |
HIP 49186 |
8.91 |
| 2026-08-06 00:00 |
10:02:46.84 |
+26:27:47.0 |
HIP 49186 |
9.18 |
| 2026-08-06 12:00 |
10:02:52.02 |
+26:27:16.0 |
HIP 49186 |
9.62 |
| 2026-08-07 00:00 |
10:02:57.21 |
+26:26:45.2 |
HIP 49186 |
10.20 |
| 2026-08-07 12:00 |
10:03:02.42 |
+26:26:14.4 |
HIP 49186 |
10.90 |
| 2026-08-08 00:00 |
10:03:07.63 |
+26:25:43.8 |
HIP 49186 |
11.70 |
| 2026-08-08 12:00 |
10:03:12.85 |
+26:25:13.3 |
HIP 49186 |
12.58 |
| 2026-08-09 00:00 |
10:03:18.08 |
+26:24:42.9 |
HIP 49186 |
13.53 |
| 2026-08-09 12:00 |
10:03:23.33 |
+26:24:12.6 |
HIP 49186 |
14.53 |
| 2026-08-10 00:00 |
10:03:28.58 |
+26:23:42.5 |
HIP 49186 |
15.57 |
| 2026-08-10 12:00 |
10:03:33.83 |
+26:23:12.4 |
HIP 49186 |
16.65 |
| 2026-08-11 00:00 |
10:03:39.10 |
+26:22:42.5 |
HIP 49186 |
17.76 |
| 2026-08-11 12:00 |
10:03:44.37 |
+26:22:12.7 |
HIP 49186 |
18.89 |
| 2026-08-12 00:00 |
10:03:49.65 |
+26:21:43.1 |
HIP 49186 |
20.04 |
| 2026-08-12 12:00 |
10:03:54.94 |
+26:21:13.6 |
HIP 49186 |
21.21 |
| 2026-08-13 00:00 |
10:04:00.23 |
+26:20:44.2 |
HIP 49429 |
21.15 |
| 2026-08-13 12:00 |
10:04:05.53 |
+26:20:15.0 |
HIP 49429 |
20.28 |
| 2026-08-14 00:00 |
10:04:10.84 |
+26:19:45.9 |
HIP 49429 |
19.46 |
| 2026-08-14 12:00 |
10:04:16.14 |
+26:19:16.9 |
HIP 49429 |
18.69 |
| 2026-08-15 00:00 |
10:04:21.46 |
+26:18:48.1 |
HIP 49429 |
17.97 |
| 2026-08-15 12:00 |
10:04:26.78 |
+26:18:19.4 |
HIP 49429 |
17.31 |
| 2026-08-16 00:00 |
10:04:32.10 |
+26:17:50.9 |
HIP 49429 |
16.73 |
| 2026-08-16 12:00 |
10:04:37.42 |
+26:17:22.5 |
HIP 49429 |
16.22 |
| 2026-08-17 00:00 |
10:04:42.75 |
+26:16:54.3 |
HIP 49429 |
15.80 |
| 2026-08-17 12:00 |
10:04:48.08 |
+26:16:26.2 |
HIP 49429 |
15.48 |
| 2026-08-18 00:00 |
10:04:53.42 |
+26:15:58.3 |
HIP 49429 |
15.25 |
| 2026-08-18 12:00 |
10:04:58.75 |
+26:15:30.6 |
HIP 49429 |
15.12 |
| 2026-08-19 00:00 |
10:05:04.09 |
+26:15:03.0 |
HIP 49429 |
15.10 |