C/1997 D1 (Mueller)
| 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) |
| 2026-02-03 00:00 |
19:58:22.75 |
-32:31:30.6 |
HIP 98310 |
6.15 |
| 2026-02-03 12:00 |
19:58:25.26 |
-32:31:25.5 |
HIP 98310 |
5.94 |
| 2026-02-04 00:00 |
19:58:27.77 |
-32:31:20.5 |
HIP 98310 |
5.77 |
| 2026-02-04 12:00 |
19:58:30.27 |
-32:31:15.5 |
HIP 98310 |
5.65 |
| 2026-02-05 00:00 |
19:58:32.77 |
-32:31:10.7 |
HIP 98310 |
5.58 |
| 2026-02-05 12:00 |
19:58:35.26 |
-32:31:05.9 |
HIP 98310 |
5.56 |
| 2026-02-06 00:00 |
19:58:37.74 |
-32:31:01.1 |
HIP 98310 |
5.59 |
| 2026-02-06 12:00 |
19:58:40.21 |
-32:30:56.5 |
HIP 98310 |
5.68 |
| 2026-02-07 00:00 |
19:58:42.68 |
-32:30:51.9 |
HIP 98310 |
5.81 |
| 2026-02-07 12:00 |
19:58:45.13 |
-32:30:47.4 |
HIP 98310 |
5.98 |
| 2026-02-08 00:00 |
19:58:47.58 |
-32:30:43.0 |
HIP 98310 |
6.19 |
| 2026-02-08 12:00 |
19:58:50.02 |
-32:30:38.7 |
HIP 98310 |
6.44 |
| 2026-02-09 00:00 |
19:58:52.46 |
-32:30:34.4 |
HIP 98310 |
6.72 |
| 2026-02-09 12:00 |
19:58:54.88 |
-32:30:30.3 |
HIP 98310 |
7.03 |
| 2026-02-10 00:00 |
19:58:57.29 |
-32:30:26.1 |
HIP 98310 |
7.36 |
| 2026-02-10 12:00 |
19:58:59.70 |
-32:30:22.1 |
HIP 98310 |
7.71 |
| 2026-02-11 00:00 |
19:59:02.09 |
-32:30:18.2 |
HIP 98310 |
8.07 |
| 2026-02-11 12:00 |
19:59:04.48 |
-32:30:14.3 |
HIP 98310 |
8.45 |
| 2026-02-12 00:00 |
19:59:06.86 |
-32:30:10.5 |
HIP 98310 |
8.84 |
| 2026-02-12 12:00 |
19:59:09.22 |
-32:30:06.8 |
HIP 98310 |
9.24 |
| 2026-02-13 00:00 |
19:59:11.58 |
-32:30:03.2 |
HIP 98310 |
9.65 |
| 2026-02-13 12:00 |
19:59:13.92 |
-32:29:59.6 |
HIP 98310 |
10.07 |
| 2026-02-14 00:00 |
19:59:16.26 |
-32:29:56.1 |
HIP 98310 |
10.49 |
| 2026-02-14 12:00 |
19:59:18.58 |
-32:29:52.8 |
HIP 98310 |
10.91 |
| 2026-02-15 00:00 |
19:59:20.90 |
-32:29:49.4 |
HIP 98310 |
11.35 |
| 2026-02-15 12:00 |
19:59:23.20 |
-32:29:46.2 |
HIP 98310 |
11.78 |
| 2026-02-16 00:00 |
19:59:25.49 |
-32:29:43.1 |
HIP 98310 |
12.21 |
| 2026-02-16 12:00 |
19:59:27.77 |
-32:29:40.0 |
HIP 98310 |
12.65 |
| 2026-02-17 00:00 |
19:59:30.04 |
-32:29:37.0 |
HIP 98310 |
13.09 |
| 2026-02-17 12:00 |
19:59:32.30 |
-32:29:34.1 |
HIP 98310 |
13.53 |
| 2026-02-18 00:00 |
19:59:34.54 |
-32:29:31.3 |
HIP 98310 |
13.97 |
| 2026-02-18 12:00 |
19:59:36.78 |
-32:29:28.5 |
HIP 98310 |
14.41 |
| 2026-02-19 00:00 |
19:59:39.00 |
-32:29:25.9 |
HIP 98310 |
14.85 |
| 2026-02-19 12:00 |
19:59:41.21 |
-32:29:23.3 |
HIP 98310 |
15.29 |
| 2026-02-20 00:00 |
19:59:43.40 |
-32:29:20.8 |
HIP 98310 |
15.73 |
| 2026-02-20 12:00 |
19:59:45.58 |
-32:29:18.4 |
HIP 98310 |
16.17 |
| 2026-02-21 00:00 |
19:59:47.75 |
-32:29:16.1 |
HIP 98310 |
16.61 |
| 2026-02-21 12:00 |
19:59:49.91 |
-32:29:13.9 |
HIP 98310 |
17.04 |
| 2026-02-22 00:00 |
19:59:52.05 |
-32:29:11.7 |
HIP 98310 |
17.48 |
| 2026-02-22 12:00 |
19:59:54.18 |
-32:29:09.6 |
HIP 98310 |
17.91 |
| 2026-02-23 00:00 |
19:59:56.30 |
-32:29:07.6 |
HIP 98310 |
18.34 |
| 2026-02-23 12:00 |
19:59:58.40 |
-32:29:05.7 |
HIP 98310 |
18.77 |
| 2026-02-24 00:00 |
20:00:00.49 |
-32:29:03.9 |
HIP 98310 |
19.20 |