| 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
$$
M_a = (9.367 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.367 |
| n |
2.000 |
| gf |
1.000 |
| 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 |
-0.9369 |
+0.030 |
| 1997-10-12 |
1998-09-02 |
+6.9714 |
-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) |
| 2026-09-20 00:00 |
19:51:28.81 |
-33:01:41.6 |
HIP 97631 |
21.19 |
| 2026-09-20 12:00 |
19:51:27.43 |
-33:01:37.4 |
HIP 97631 |
20.98 |
| 2026-09-21 00:00 |
19:51:26.07 |
-33:01:33.2 |
HIP 97631 |
20.77 |
| 2026-09-21 12:00 |
19:51:24.74 |
-33:01:28.9 |
HIP 97631 |
20.56 |
| 2026-09-22 00:00 |
19:51:23.42 |
-33:01:24.5 |
HIP 97631 |
20.36 |
| 2026-09-22 12:00 |
19:51:22.12 |
-33:01:20.1 |
HIP 97631 |
20.16 |
| 2026-09-23 00:00 |
19:51:20.85 |
-33:01:15.6 |
HIP 97631 |
19.97 |
| 2026-09-23 12:00 |
19:51:19.60 |
-33:01:11.0 |
HIP 97631 |
19.78 |
| 2026-09-24 00:00 |
19:51:18.36 |
-33:01:06.3 |
HIP 97631 |
19.59 |
| 2026-09-24 12:00 |
19:51:17.16 |
-33:01:01.5 |
HIP 97631 |
19.40 |
| 2026-09-25 00:00 |
19:51:15.97 |
-33:00:56.7 |
HIP 97631 |
19.22 |
| 2026-09-25 12:00 |
19:51:14.80 |
-33:00:51.8 |
HIP 97631 |
19.03 |
| 2026-09-26 00:00 |
19:51:13.66 |
-33:00:46.9 |
HIP 97631 |
18.86 |
| 2026-09-26 12:00 |
19:51:12.53 |
-33:00:41.8 |
HIP 97631 |
18.68 |
| 2026-09-27 00:00 |
19:51:11.43 |
-33:00:36.7 |
HIP 97631 |
18.51 |
| 2026-09-27 12:00 |
19:51:10.36 |
-33:00:31.5 |
HIP 97631 |
18.33 |
| 2026-09-28 00:00 |
19:51:09.30 |
-33:00:26.2 |
HIP 97631 |
18.17 |
| 2026-09-28 12:00 |
19:51:08.27 |
-33:00:20.9 |
HIP 97631 |
18.00 |
| 2026-09-29 00:00 |
19:51:07.25 |
-33:00:15.5 |
HIP 97631 |
17.83 |
| 2026-09-29 12:00 |
19:51:06.26 |
-33:00:10.0 |
HIP 97631 |
17.67 |
| 2026-09-30 00:00 |
19:51:05.30 |
-33:00:04.5 |
HIP 97631 |
17.51 |
| 2026-09-30 12:00 |
19:51:04.35 |
-32:59:58.9 |
HIP 97631 |
17.35 |
| 2026-10-01 00:00 |
19:51:03.43 |
-32:59:53.2 |
HIP 97631 |
17.20 |
| 2026-10-01 12:00 |
19:51:02.53 |
-32:59:47.4 |
HIP 97631 |
17.04 |
| 2026-10-02 00:00 |
19:51:01.65 |
-32:59:41.6 |
HIP 97631 |
16.89 |
| 2026-10-02 12:00 |
19:51:00.80 |
-32:59:35.7 |
HIP 97631 |
16.74 |
| 2026-10-03 00:00 |
19:50:59.97 |
-32:59:29.8 |
HIP 97631 |
16.59 |
| 2026-10-03 12:00 |
19:50:59.16 |
-32:59:23.8 |
HIP 97631 |
16.44 |
| 2026-10-04 00:00 |
19:50:58.37 |
-32:59:17.7 |
HIP 97631 |
16.29 |
| 2026-10-04 12:00 |
19:50:57.61 |
-32:59:11.5 |
HIP 97631 |
16.15 |
| 2026-10-05 00:00 |
19:50:56.87 |
-32:59:05.3 |
HIP 97631 |
16.00 |
| 2026-10-05 12:00 |
19:50:56.15 |
-32:58:59.0 |
HIP 97631 |
15.86 |
| 2026-10-06 00:00 |
19:50:55.46 |
-32:58:52.6 |
HIP 97631 |
15.72 |
| 2026-10-06 12:00 |
19:50:54.79 |
-32:58:46.2 |
HIP 97631 |
15.58 |
| 2026-10-07 00:00 |
19:50:54.14 |
-32:58:39.7 |
HIP 97631 |
15.44 |
| 2026-10-07 12:00 |
19:50:53.51 |
-32:58:33.1 |
HIP 97631 |
15.30 |
| 2026-10-08 00:00 |
19:50:52.91 |
-32:58:26.5 |
HIP 97631 |
15.16 |
| 2026-10-08 12:00 |
19:50:52.34 |
-32:58:19.8 |
HIP 97631 |
15.02 |
| 2026-10-09 00:00 |
19:50:51.78 |
-32:58:13.1 |
HIP 97631 |
14.89 |
| 2026-10-09 12:00 |
19:50:51.25 |
-32:58:06.3 |
HIP 97631 |
14.75 |
| 2026-10-10 00:00 |
19:50:50.74 |
-32:57:59.4 |
HIP 97631 |
14.61 |
| 2026-10-10 12:00 |
19:50:50.26 |
-32:57:52.5 |
HIP 97631 |
14.48 |
| 2026-10-11 00:00 |
19:50:49.80 |
-32:57:45.5 |
HIP 97631 |
14.34 |