| Parameter |
Value |
| Designation |
C/1993 A1 (Mueller) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1994-01-12T21:38:07.189440Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:43Z |
| Obs used |
714 |
| NEO |
- |
| M1 |
8.100 |
| K1 |
4.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1993-08-20.0000000 |
| e |
1.00184088 |
| q (au) |
1.937455 |
| a (au) |
-1052.462705 |
| i (deg) |
124.878071 |
| Ω (om, deg) |
144.720539 |
| ω (w, deg) |
130.666066 |
| M (ma, deg) |
-0.004212 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.190 + 3.446\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.190 |
| n |
3.446 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.989 |
| δ90 |
1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1992-11-26 |
1993-08-06 |
+1.7238 |
-0.931 |
| 1993-08-06 |
1994-01-12 |
-3.7755 |
+1.282 |
| 1994-01-13 |
1994-07-15 |
+9.6590 |
-2.801 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
11:30:44.44 |
-53:26:47.2 |
HIP 56071 |
15.01 |
| 2026-09-20 12:00 |
11:30:47.59 |
-53:26:55.7 |
HIP 56071 |
15.24 |
| 2026-09-21 00:00 |
11:30:50.74 |
-53:27:04.4 |
HIP 56071 |
15.48 |
| 2026-09-21 12:00 |
11:30:53.89 |
-53:27:13.3 |
HIP 56071 |
15.73 |
| 2026-09-22 00:00 |
11:30:57.04 |
-53:27:22.5 |
HIP 56071 |
15.99 |
| 2026-09-22 12:00 |
11:31:00.18 |
-53:27:31.9 |
HIP 56071 |
16.26 |
| 2026-09-23 00:00 |
11:31:03.32 |
-53:27:41.4 |
HIP 56071 |
16.53 |
| 2026-09-23 12:00 |
11:31:06.45 |
-53:27:51.2 |
HIP 56071 |
16.82 |
| 2026-09-24 00:00 |
11:31:09.58 |
-53:28:01.2 |
HIP 56071 |
17.10 |
| 2026-09-24 12:00 |
11:31:12.71 |
-53:28:11.4 |
HIP 56071 |
17.40 |
| 2026-09-25 00:00 |
11:31:15.83 |
-53:28:21.7 |
HIP 56071 |
17.70 |
| 2026-09-25 12:00 |
11:31:18.94 |
-53:28:32.3 |
HIP 56071 |
18.01 |
| 2026-09-26 00:00 |
11:31:22.06 |
-53:28:43.1 |
HIP 56071 |
18.32 |
| 2026-09-26 12:00 |
11:31:25.16 |
-53:28:54.1 |
HIP 56071 |
18.64 |
| 2026-09-27 00:00 |
11:31:28.27 |
-53:29:05.3 |
HIP 56071 |
18.97 |
| 2026-09-27 12:00 |
11:31:31.36 |
-53:29:16.7 |
HIP 56071 |
19.30 |
| 2026-09-28 00:00 |
11:31:34.45 |
-53:29:28.3 |
HIP 56071 |
19.64 |
| 2026-09-28 12:00 |
11:31:37.54 |
-53:29:40.2 |
HIP 56071 |
19.98 |
| 2026-09-29 00:00 |
11:31:40.62 |
-53:29:52.2 |
HIP 56071 |
20.32 |
| 2026-09-29 12:00 |
11:31:43.69 |
-53:30:04.4 |
HIP 56071 |
20.67 |
| 2026-09-30 00:00 |
11:31:46.76 |
-53:30:16.8 |
HIP 56406 |
20.97 |
| 2026-09-30 12:00 |
11:31:49.82 |
-53:30:29.4 |
HIP 56406 |
20.68 |
| 2026-10-01 00:00 |
11:31:52.88 |
-53:30:42.2 |
HIP 56406 |
20.39 |
| 2026-10-01 12:00 |
11:31:55.92 |
-53:30:55.1 |
HIP 56406 |
20.12 |
| 2026-10-02 00:00 |
11:31:58.96 |
-53:31:08.3 |
HIP 56406 |
19.85 |
| 2026-10-02 12:00 |
11:32:02.00 |
-53:31:21.7 |
HIP 56406 |
19.60 |
| 2026-10-03 00:00 |
11:32:05.02 |
-53:31:35.3 |
HIP 56406 |
19.36 |
| 2026-10-03 12:00 |
11:32:08.04 |
-53:31:49.0 |
HIP 56406 |
19.14 |
| 2026-10-04 00:00 |
11:32:11.05 |
-53:32:03.0 |
HIP 56406 |
18.93 |
| 2026-10-04 12:00 |
11:32:14.05 |
-53:32:17.2 |
HIP 56406 |
18.73 |
| 2026-10-05 00:00 |
11:32:17.04 |
-53:32:31.5 |
HIP 56406 |
18.55 |
| 2026-10-05 12:00 |
11:32:20.03 |
-53:32:46.0 |
HIP 56406 |
18.38 |
| 2026-10-06 00:00 |
11:32:23.00 |
-53:33:00.7 |
HIP 56406 |
18.23 |
| 2026-10-06 12:00 |
11:32:25.97 |
-53:33:15.6 |
HIP 56406 |
18.10 |
| 2026-10-07 00:00 |
11:32:28.93 |
-53:33:30.7 |
HIP 56406 |
17.98 |
| 2026-10-07 12:00 |
11:32:31.88 |
-53:33:46.0 |
HIP 56406 |
17.88 |
| 2026-10-08 00:00 |
11:32:34.81 |
-53:34:01.5 |
HIP 56406 |
17.79 |
| 2026-10-08 12:00 |
11:32:37.74 |
-53:34:17.1 |
HIP 56406 |
17.72 |
| 2026-10-09 00:00 |
11:32:40.66 |
-53:34:32.9 |
HIP 56406 |
17.68 |
| 2026-10-09 12:00 |
11:32:43.57 |
-53:34:48.9 |
HIP 56406 |
17.64 |
| 2026-10-10 00:00 |
11:32:46.46 |
-53:35:05.1 |
HIP 56406 |
17.63 |
| 2026-10-10 12:00 |
11:32:49.35 |
-53:35:21.5 |
HIP 56406 |
17.64 |
| 2026-10-11 00:00 |
11:32:52.22 |
-53:35:38.0 |
HIP 56406 |
17.66 |