| Parameter |
Value |
| Designation |
C/1998 K1 (Mueller) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-09-01T00:55:41.113920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:53Z |
| Obs used |
171 |
| NEO |
- |
| M1 |
8.000 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1998-06-05.0000000 |
| e |
0.94515162 |
| q (au) |
3.416610 |
| a (au) |
62.291906 |
| i (deg) |
35.636035 |
| Ω (om, deg) |
18.256263 |
| ω (w, deg) |
165.250246 |
| M (ma, deg) |
359.823506 |
Magnitude
Scatter + Global Linear
$$
M_a = (4.128 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
4.128 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.998 |
| k |
1.000 |
| 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) |
| 2026-05-12 00:00 |
23:39:50.18 |
-26:30:19.3 |
HIP 116807 |
19.97 |
| 2026-05-12 12:00 |
23:39:51.80 |
-26:30:22.9 |
HIP 116807 |
19.88 |
| 2026-05-13 00:00 |
23:39:53.40 |
-26:30:26.8 |
HIP 116807 |
19.80 |
| 2026-05-13 12:00 |
23:39:54.98 |
-26:30:30.8 |
HIP 116807 |
19.74 |
| 2026-05-14 00:00 |
23:39:56.54 |
-26:30:35.0 |
HIP 116807 |
19.68 |
| 2026-05-14 12:00 |
23:39:58.08 |
-26:30:39.4 |
HIP 116807 |
19.64 |
| 2026-05-15 00:00 |
23:39:59.61 |
-26:30:44.0 |
HIP 116807 |
19.60 |
| 2026-05-15 12:00 |
23:40:01.11 |
-26:30:48.7 |
HIP 116807 |
19.58 |
| 2026-05-16 00:00 |
23:40:02.59 |
-26:30:53.7 |
HIP 116807 |
19.57 |
| 2026-05-16 12:00 |
23:40:04.06 |
-26:30:58.7 |
HIP 116807 |
19.56 |
| 2026-05-17 00:00 |
23:40:05.50 |
-26:31:04.0 |
HIP 116807 |
19.57 |
| 2026-05-17 12:00 |
23:40:06.93 |
-26:31:09.5 |
HIP 116807 |
19.58 |
| 2026-05-18 00:00 |
23:40:08.33 |
-26:31:15.1 |
HIP 116807 |
19.61 |
| 2026-05-18 12:00 |
23:40:09.71 |
-26:31:20.9 |
HIP 116807 |
19.64 |
| 2026-05-19 00:00 |
23:40:11.08 |
-26:31:26.9 |
HIP 116807 |
19.69 |
| 2026-05-19 12:00 |
23:40:12.42 |
-26:31:33.0 |
HIP 116807 |
19.74 |
| 2026-05-20 00:00 |
23:40:13.74 |
-26:31:39.3 |
HIP 116807 |
19.80 |
| 2026-05-20 12:00 |
23:40:15.04 |
-26:31:45.8 |
HIP 116807 |
19.87 |
| 2026-05-21 00:00 |
23:40:16.33 |
-26:31:52.5 |
HIP 116807 |
19.94 |
| 2026-05-21 12:00 |
23:40:17.59 |
-26:31:59.3 |
HIP 116807 |
20.03 |
| 2026-05-22 00:00 |
23:40:18.83 |
-26:32:06.4 |
HIP 116807 |
20.12 |
| 2026-05-22 12:00 |
23:40:20.05 |
-26:32:13.5 |
HIP 116807 |
20.22 |
| 2026-05-23 00:00 |
23:40:21.25 |
-26:32:20.9 |
HIP 116807 |
20.32 |
| 2026-05-23 12:00 |
23:40:22.42 |
-26:32:28.4 |
HIP 116807 |
20.44 |
| 2026-05-24 00:00 |
23:40:23.58 |
-26:32:36.1 |
HIP 116807 |
20.55 |
| 2026-05-24 12:00 |
23:40:24.72 |
-26:32:43.9 |
HIP 116801 |
20.57 |
| 2026-05-25 00:00 |
23:40:25.83 |
-26:32:51.9 |
HIP 116801 |
20.45 |
| 2026-05-25 12:00 |
23:40:26.92 |
-26:33:00.1 |
HIP 116801 |
20.34 |
| 2026-05-26 00:00 |
23:40:28.00 |
-26:33:08.4 |
HIP 116801 |
20.22 |
| 2026-05-26 12:00 |
23:40:29.05 |
-26:33:17.0 |
HIP 116801 |
20.10 |
| 2026-05-27 00:00 |
23:40:30.07 |
-26:33:25.6 |
HIP 116801 |
19.98 |
| 2026-05-27 12:00 |
23:40:31.08 |
-26:33:34.5 |
HIP 116801 |
19.87 |
| 2026-05-28 00:00 |
23:40:32.07 |
-26:33:43.5 |
HIP 116801 |
19.75 |
| 2026-05-28 12:00 |
23:40:33.03 |
-26:33:52.6 |
HIP 116801 |
19.63 |
| 2026-05-29 00:00 |
23:40:33.98 |
-26:34:01.9 |
HIP 116801 |
19.51 |
| 2026-05-29 12:00 |
23:40:34.90 |
-26:34:11.4 |
HIP 116801 |
19.39 |
| 2026-05-30 00:00 |
23:40:35.80 |
-26:34:21.0 |
HIP 116801 |
19.27 |
| 2026-05-30 12:00 |
23:40:36.68 |
-26:34:30.8 |
HIP 116801 |
19.14 |
| 2026-05-31 00:00 |
23:40:37.53 |
-26:34:40.8 |
HIP 116801 |
19.02 |
| 2026-05-31 12:00 |
23:40:38.37 |
-26:34:50.9 |
HIP 116801 |
18.90 |
| 2026-06-01 00:00 |
23:40:39.18 |
-26:35:01.1 |
HIP 116801 |
18.77 |
| 2026-06-01 12:00 |
23:40:39.97 |
-26:35:11.5 |
HIP 116801 |
18.65 |
| 2026-06-02 00:00 |
23:40:40.74 |
-26:35:22.1 |
HIP 116801 |
18.52 |