| 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) |
| 2026-05-12 00:00 |
11:24:42.64 |
-54:37:16.2 |
HIP 55782 |
22.72 |
| 2026-05-12 12:00 |
11:24:40.90 |
-54:36:48.2 |
HIP 55782 |
22.40 |
| 2026-05-13 00:00 |
11:24:39.18 |
-54:36:20.1 |
HIP 55782 |
22.08 |
| 2026-05-13 12:00 |
11:24:37.49 |
-54:35:51.9 |
HIP 55782 |
21.78 |
| 2026-05-14 00:00 |
11:24:35.83 |
-54:35:23.7 |
HIP 55782 |
21.48 |
| 2026-05-14 12:00 |
11:24:34.19 |
-54:34:55.4 |
HIP 55782 |
21.18 |
| 2026-05-15 00:00 |
11:24:32.58 |
-54:34:27.1 |
HIP 55782 |
20.89 |
| 2026-05-15 12:00 |
11:24:31.00 |
-54:33:58.7 |
HIP 55782 |
20.61 |
| 2026-05-16 00:00 |
11:24:29.44 |
-54:33:30.3 |
HIP 55782 |
20.34 |
| 2026-05-16 12:00 |
11:24:27.91 |
-54:33:01.8 |
HIP 55782 |
20.07 |
| 2026-05-17 00:00 |
11:24:26.41 |
-54:32:33.3 |
HIP 55782 |
19.81 |
| 2026-05-17 12:00 |
11:24:24.93 |
-54:32:04.7 |
HIP 55782 |
19.55 |
| 2026-05-18 00:00 |
11:24:23.48 |
-54:31:36.1 |
HIP 55782 |
19.31 |
| 2026-05-18 12:00 |
11:24:22.06 |
-54:31:07.5 |
HIP 55782 |
19.07 |
| 2026-05-19 00:00 |
11:24:20.67 |
-54:30:38.8 |
HIP 55782 |
18.84 |
| 2026-05-19 12:00 |
11:24:19.30 |
-54:30:10.1 |
HIP 55782 |
18.62 |
| 2026-05-20 00:00 |
11:24:17.96 |
-54:29:41.3 |
HIP 55782 |
18.41 |
| 2026-05-20 12:00 |
11:24:16.65 |
-54:29:12.6 |
HIP 55782 |
18.21 |
| 2026-05-21 00:00 |
11:24:15.36 |
-54:28:43.8 |
HIP 55782 |
18.02 |
| 2026-05-21 12:00 |
11:24:14.11 |
-54:28:15.0 |
HIP 55782 |
17.84 |
| 2026-05-22 00:00 |
11:24:12.88 |
-54:27:46.1 |
HIP 55782 |
17.66 |
| 2026-05-22 12:00 |
11:24:11.68 |
-54:27:17.3 |
HIP 55782 |
17.50 |
| 2026-05-23 00:00 |
11:24:10.51 |
-54:26:48.4 |
HIP 55782 |
17.35 |
| 2026-05-23 12:00 |
11:24:09.36 |
-54:26:19.5 |
HIP 55782 |
17.20 |
| 2026-05-24 00:00 |
11:24:08.24 |
-54:25:50.6 |
HIP 55782 |
17.07 |
| 2026-05-24 12:00 |
11:24:07.15 |
-54:25:21.7 |
HIP 55782 |
16.95 |
| 2026-05-25 00:00 |
11:24:06.09 |
-54:24:52.7 |
HIP 55782 |
16.84 |
| 2026-05-25 12:00 |
11:24:05.06 |
-54:24:23.8 |
HIP 55782 |
16.74 |
| 2026-05-26 00:00 |
11:24:04.05 |
-54:23:54.9 |
HIP 55782 |
16.65 |
| 2026-05-26 12:00 |
11:24:03.08 |
-54:23:25.9 |
HIP 55782 |
16.57 |
| 2026-05-27 00:00 |
11:24:02.13 |
-54:22:57.0 |
HIP 55782 |
16.51 |
| 2026-05-27 12:00 |
11:24:01.21 |
-54:22:28.0 |
HIP 55782 |
16.45 |
| 2026-05-28 00:00 |
11:24:00.31 |
-54:21:59.1 |
HIP 55782 |
16.41 |
| 2026-05-28 12:00 |
11:23:59.45 |
-54:21:30.2 |
HIP 55782 |
16.38 |
| 2026-05-29 00:00 |
11:23:58.61 |
-54:21:01.2 |
HIP 55782 |
16.36 |
| 2026-05-29 12:00 |
11:23:57.80 |
-54:20:32.3 |
HIP 55782 |
16.35 |
| 2026-05-30 00:00 |
11:23:57.02 |
-54:20:03.4 |
HIP 55782 |
16.35 |
| 2026-05-30 12:00 |
11:23:56.27 |
-54:19:34.5 |
HIP 55782 |
16.36 |
| 2026-05-31 00:00 |
11:23:55.54 |
-54:19:05.7 |
HIP 55782 |
16.38 |
| 2026-05-31 12:00 |
11:23:54.84 |
-54:18:36.8 |
HIP 55782 |
16.42 |
| 2026-06-01 00:00 |
11:23:54.18 |
-54:18:07.9 |
HIP 55782 |
16.46 |
| 2026-06-01 12:00 |
11:23:53.54 |
-54:17:39.1 |
HIP 55782 |
16.52 |
| 2026-06-02 00:00 |
11:23:52.92 |
-54:17:10.3 |
HIP 55782 |
16.58 |