| Parameter |
Value |
| Designation |
C/1997 D1 (Mueller) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1997-10-11T14:47:59.519040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:50Z |
| Obs used |
430 |
| NEO |
- |
| M1 |
6.000 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1997-07-13.0000000 |
| e |
1.00115666 |
| q (au) |
2.247622 |
| a (au) |
-1943.197807 |
| i (deg) |
141.889605 |
| Ω (om, deg) |
279.171154 |
| ω (w, deg) |
184.962587 |
| M (ma, deg) |
-0.001043 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.368 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.368 |
| n |
2.000 |
| gf |
0.999 |
| gb |
-0.611 |
| k |
0.988 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1997-02-17 |
1997-10-11 |
-0.9370 |
+0.030 |
| 1997-10-12 |
1998-09-02 |
+6.9718 |
-2.273 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
20:01:35.11 |
-32:29:48.9 |
HIP 98499 |
22.65 |
| 2026-03-26 12:00 |
20:01:36.10 |
-32:29:52.1 |
HIP 98499 |
22.81 |
| 2026-03-27 00:00 |
20:01:37.07 |
-32:29:55.5 |
HIP 98499 |
22.97 |
| 2026-03-27 12:00 |
20:01:38.01 |
-32:29:59.0 |
HIP 98499 |
23.12 |
| 2026-03-28 00:00 |
20:01:38.94 |
-32:30:02.5 |
HIP 98499 |
23.28 |
| 2026-03-28 12:00 |
20:01:39.84 |
-32:30:06.1 |
HIP 98499 |
23.43 |
| 2026-03-29 00:00 |
20:01:40.72 |
-32:30:09.8 |
HIP 98499 |
23.59 |
| 2026-03-29 12:00 |
20:01:41.58 |
-32:30:13.5 |
HIP 98499 |
23.74 |
| 2026-03-30 00:00 |
20:01:42.42 |
-32:30:17.4 |
HIP 98499 |
23.89 |
| 2026-03-30 12:00 |
20:01:43.23 |
-32:30:21.3 |
HIP 98499 |
24.04 |
| 2026-03-31 00:00 |
20:01:44.03 |
-32:30:25.3 |
HIP 98499 |
24.19 |
| 2026-03-31 12:00 |
20:01:44.80 |
-32:30:29.3 |
HIP 98499 |
24.34 |
| 2026-04-01 00:00 |
20:01:45.55 |
-32:30:33.5 |
HIP 98499 |
24.49 |
| 2026-04-01 12:00 |
20:01:46.27 |
-32:30:37.7 |
HIP 98499 |
24.64 |
| 2026-04-02 00:00 |
20:01:46.98 |
-32:30:42.0 |
HIP 98499 |
24.78 |
| 2026-04-02 12:00 |
20:01:47.66 |
-32:30:46.4 |
HIP 98499 |
24.92 |
| 2026-04-03 00:00 |
20:01:48.33 |
-32:30:50.8 |
HIP 98499 |
25.07 |
| 2026-04-03 12:00 |
20:01:48.96 |
-32:30:55.3 |
HIP 98499 |
25.21 |
| 2026-04-04 00:00 |
20:01:49.58 |
-32:31:00.0 |
HIP 98499 |
25.34 |
| 2026-04-04 12:00 |
20:01:50.18 |
-32:31:04.6 |
HIP 98499 |
25.48 |
| 2026-04-05 00:00 |
20:01:50.75 |
-32:31:09.3 |
HIP 98499 |
25.62 |
| 2026-04-05 12:00 |
20:01:51.30 |
-32:31:14.1 |
HIP 98499 |
25.75 |
| 2026-04-06 00:00 |
20:01:51.83 |
-32:31:19.0 |
HIP 98499 |
25.88 |
| 2026-04-06 12:00 |
20:01:52.33 |
-32:31:24.0 |
HIP 98499 |
26.01 |
| 2026-04-07 00:00 |
20:01:52.81 |
-32:31:29.0 |
HIP 98499 |
26.14 |
| 2026-04-07 12:00 |
20:01:53.27 |
-32:31:34.1 |
HIP 98499 |
26.27 |
| 2026-04-08 00:00 |
20:01:53.71 |
-32:31:39.3 |
HIP 98499 |
26.39 |
| 2026-04-08 12:00 |
20:01:54.12 |
-32:31:44.5 |
HIP 98499 |
26.51 |
| 2026-04-09 00:00 |
20:01:54.51 |
-32:31:49.9 |
HIP 98499 |
26.63 |
| 2026-04-09 12:00 |
20:01:54.88 |
-32:31:55.3 |
HIP 98499 |
26.75 |
| 2026-04-10 00:00 |
20:01:55.23 |
-32:32:00.7 |
HIP 98499 |
26.87 |
| 2026-04-10 12:00 |
20:01:55.55 |
-32:32:06.2 |
HIP 98499 |
26.98 |
| 2026-04-11 00:00 |
20:01:55.85 |
-32:32:11.8 |
HIP 98499 |
27.09 |
| 2026-04-11 12:00 |
20:01:56.12 |
-32:32:17.5 |
HIP 98499 |
27.21 |
| 2026-04-12 00:00 |
20:01:56.38 |
-32:32:23.2 |
HIP 98499 |
27.31 |
| 2026-04-12 12:00 |
20:01:56.61 |
-32:32:29.1 |
HIP 98499 |
27.42 |
| 2026-04-13 00:00 |
20:01:56.81 |
-32:32:34.9 |
HIP 98499 |
27.52 |
| 2026-04-13 12:00 |
20:01:57.00 |
-32:32:40.9 |
HIP 98499 |
27.63 |
| 2026-04-14 00:00 |
20:01:57.16 |
-32:32:46.9 |
HIP 98499 |
27.73 |
| 2026-04-14 12:00 |
20:01:57.29 |
-32:32:52.9 |
HIP 98499 |
27.83 |
| 2026-04-15 00:00 |
20:01:57.41 |
-32:32:59.1 |
HIP 98499 |
27.92 |
| 2026-04-15 12:00 |
20:01:57.50 |
-32:33:05.3 |
HIP 98499 |
28.02 |
| 2026-04-16 00:00 |
20:01:57.57 |
-32:33:11.6 |
HIP 98499 |
28.11 |