| 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 |
-0.501 |
| 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) |
| 2026-07-29 00:00 |
23:39:40.38 |
-27:07:41.2 |
HIP 116730 |
4.30 |
| 2026-07-29 12:00 |
23:39:38.63 |
-27:08:01.6 |
HIP 116730 |
3.81 |
| 2026-07-30 00:00 |
23:39:36.86 |
-27:08:22.0 |
HIP 116730 |
3.33 |
| 2026-07-30 12:00 |
23:39:35.08 |
-27:08:42.3 |
HIP 116730 |
2.85 |
| 2026-07-31 00:00 |
23:39:33.27 |
-27:09:02.7 |
HIP 116730 |
2.39 |
| 2026-07-31 12:00 |
23:39:31.45 |
-27:09:23.1 |
HIP 116730 |
1.95 |
| 2026-08-01 00:00 |
23:39:29.62 |
-27:09:43.4 |
HIP 116730 |
1.58 |
| 2026-08-01 12:00 |
23:39:27.76 |
-27:10:03.8 |
HIP 116730 |
1.31 |
| 2026-08-02 00:00 |
23:39:25.89 |
-27:10:24.1 |
HIP 116730 |
1.22 |
| 2026-08-02 12:00 |
23:39:24.00 |
-27:10:44.4 |
HIP 116730 |
1.36 |
| 2026-08-03 00:00 |
23:39:22.10 |
-27:11:04.7 |
HIP 116730 |
1.67 |
| 2026-08-03 12:00 |
23:39:20.17 |
-27:11:25.0 |
HIP 116730 |
2.08 |
| 2026-08-04 00:00 |
23:39:18.23 |
-27:11:45.3 |
HIP 116730 |
2.54 |
| 2026-08-04 12:00 |
23:39:16.28 |
-27:12:05.6 |
HIP 116730 |
3.03 |
| 2026-08-05 00:00 |
23:39:14.31 |
-27:12:25.8 |
HIP 116730 |
3.54 |
| 2026-08-05 12:00 |
23:39:12.32 |
-27:12:46.0 |
HIP 116730 |
4.07 |
| 2026-08-06 00:00 |
23:39:10.31 |
-27:13:06.2 |
HIP 116730 |
4.60 |
| 2026-08-06 12:00 |
23:39:08.29 |
-27:13:26.3 |
HIP 116730 |
5.14 |
| 2026-08-07 00:00 |
23:39:06.26 |
-27:13:46.5 |
HIP 116730 |
5.69 |
| 2026-08-07 12:00 |
23:39:04.20 |
-27:14:06.6 |
HIP 116730 |
6.24 |
| 2026-08-08 00:00 |
23:39:02.13 |
-27:14:26.6 |
HIP 116730 |
6.79 |
| 2026-08-08 12:00 |
23:39:00.05 |
-27:14:46.7 |
HIP 116730 |
7.35 |
| 2026-08-09 00:00 |
23:38:57.95 |
-27:15:06.7 |
HIP 116730 |
7.92 |
| 2026-08-09 12:00 |
23:38:55.84 |
-27:15:26.6 |
HIP 116730 |
8.48 |
| 2026-08-10 00:00 |
23:38:53.71 |
-27:15:46.6 |
HIP 116730 |
9.05 |
| 2026-08-10 12:00 |
23:38:51.56 |
-27:16:06.5 |
HIP 116730 |
9.62 |
| 2026-08-11 00:00 |
23:38:49.41 |
-27:16:26.3 |
HIP 116730 |
10.20 |
| 2026-08-11 12:00 |
23:38:47.23 |
-27:16:46.1 |
HIP 116730 |
10.78 |
| 2026-08-12 00:00 |
23:38:45.04 |
-27:17:05.9 |
HIP 116730 |
11.36 |
| 2026-08-12 12:00 |
23:38:42.84 |
-27:17:25.6 |
HIP 116730 |
11.94 |
| 2026-08-13 00:00 |
23:38:40.63 |
-27:17:45.2 |
HIP 116730 |
12.53 |
| 2026-08-13 12:00 |
23:38:38.40 |
-27:18:04.8 |
HIP 116730 |
13.11 |
| 2026-08-14 00:00 |
23:38:36.15 |
-27:18:24.4 |
HIP 116730 |
13.70 |
| 2026-08-14 12:00 |
23:38:33.90 |
-27:18:43.9 |
HIP 116730 |
14.29 |
| 2026-08-15 00:00 |
23:38:31.63 |
-27:19:03.3 |
HIP 116730 |
14.89 |
| 2026-08-15 12:00 |
23:38:29.34 |
-27:19:22.7 |
HIP 116730 |
15.48 |
| 2026-08-16 00:00 |
23:38:27.05 |
-27:19:42.0 |
HIP 116730 |
16.08 |
| 2026-08-16 12:00 |
23:38:24.74 |
-27:20:01.3 |
HIP 116730 |
16.68 |
| 2026-08-17 00:00 |
23:38:22.42 |
-27:20:20.5 |
HIP 116730 |
17.28 |
| 2026-08-17 12:00 |
23:38:20.09 |
-27:20:39.6 |
HIP 116730 |
17.89 |
| 2026-08-18 00:00 |
23:38:17.74 |
-27:20:58.7 |
HIP 116730 |
18.49 |
| 2026-08-18 12:00 |
23:38:15.38 |
-27:21:17.6 |
HIP 116730 |
19.10 |
| 2026-08-19 00:00 |
23:38:13.01 |
-27:21:36.6 |
HIP 116730 |
19.71 |