| Parameter |
Value |
| Designation |
C/2000 O1 (Koehn) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2000-01-27T17:38:15.144000Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:05Z |
| Obs used |
64 |
| NEO |
- |
| M1 |
5.100 |
| K1 |
11.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2000-05-14.0000000 |
| e |
1.00000217 |
| q (au) |
5.921780 |
| a (au) |
-2729545.221721 |
| i (deg) |
148.104189 |
| Ω (om, deg) |
88.882672 |
| ω (w, deg) |
55.164253 |
| M (ma, deg) |
0.000000 |
Magnitude
Scatter + Global Linear
$$
M_a = (2.023 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
2.023 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
17:00:00.63 |
-29:23:33.3 |
HIP 83258 |
21.34 |
| 2026-09-20 12:00 |
17:00:01.04 |
-29:23:31.0 |
HIP 83258 |
21.31 |
| 2026-09-21 00:00 |
17:00:01.47 |
-29:23:28.7 |
HIP 83258 |
21.29 |
| 2026-09-21 12:00 |
17:00:01.93 |
-29:23:26.4 |
HIP 83258 |
21.26 |
| 2026-09-22 00:00 |
17:00:02.41 |
-29:23:24.2 |
HIP 83258 |
21.22 |
| 2026-09-22 12:00 |
17:00:02.92 |
-29:23:22.0 |
HIP 83258 |
21.18 |
| 2026-09-23 00:00 |
17:00:03.45 |
-29:23:19.9 |
HIP 83258 |
21.14 |
| 2026-09-23 12:00 |
17:00:04.00 |
-29:23:17.8 |
HIP 83258 |
21.10 |
| 2026-09-24 00:00 |
17:00:04.58 |
-29:23:15.7 |
HIP 83258 |
21.05 |
| 2026-09-24 12:00 |
17:00:05.19 |
-29:23:13.7 |
HIP 83258 |
21.00 |
| 2026-09-25 00:00 |
17:00:05.81 |
-29:23:11.8 |
HIP 83258 |
20.95 |
| 2026-09-25 12:00 |
17:00:06.47 |
-29:23:09.9 |
HIP 83258 |
20.90 |
| 2026-09-26 00:00 |
17:00:07.14 |
-29:23:08.0 |
HIP 83258 |
20.84 |
| 2026-09-26 12:00 |
17:00:07.84 |
-29:23:06.2 |
HIP 83258 |
20.78 |
| 2026-09-27 00:00 |
17:00:08.57 |
-29:23:04.4 |
HIP 83258 |
20.71 |
| 2026-09-27 12:00 |
17:00:09.31 |
-29:23:02.7 |
HIP 83258 |
20.65 |
| 2026-09-28 00:00 |
17:00:10.09 |
-29:23:01.0 |
HIP 83258 |
20.58 |
| 2026-09-28 12:00 |
17:00:10.88 |
-29:22:59.3 |
HIP 83258 |
20.51 |
| 2026-09-29 00:00 |
17:00:11.70 |
-29:22:57.7 |
HIP 83258 |
20.44 |
| 2026-09-29 12:00 |
17:00:12.54 |
-29:22:56.1 |
HIP 83258 |
20.36 |
| 2026-09-30 00:00 |
17:00:13.41 |
-29:22:54.6 |
HIP 83258 |
20.29 |
| 2026-09-30 12:00 |
17:00:14.30 |
-29:22:53.2 |
HIP 83258 |
20.21 |
| 2026-10-01 00:00 |
17:00:15.21 |
-29:22:51.7 |
HIP 83258 |
20.13 |
| 2026-10-01 12:00 |
17:00:16.15 |
-29:22:50.4 |
HIP 83258 |
20.05 |
| 2026-10-02 00:00 |
17:00:17.11 |
-29:22:49.0 |
HIP 83258 |
19.97 |
| 2026-10-02 12:00 |
17:00:18.10 |
-29:22:47.8 |
HIP 83258 |
19.88 |
| 2026-10-03 00:00 |
17:00:19.10 |
-29:22:46.5 |
HIP 83258 |
19.80 |
| 2026-10-03 12:00 |
17:00:20.13 |
-29:22:45.3 |
HIP 83258 |
19.71 |
| 2026-10-04 00:00 |
17:00:21.18 |
-29:22:44.2 |
HIP 83258 |
19.63 |
| 2026-10-04 12:00 |
17:00:22.26 |
-29:22:43.1 |
HIP 83258 |
19.54 |
| 2026-10-05 00:00 |
17:00:23.36 |
-29:22:42.1 |
HIP 83258 |
19.45 |
| 2026-10-05 12:00 |
17:00:24.48 |
-29:22:41.1 |
HIP 83258 |
19.37 |
| 2026-10-06 00:00 |
17:00:25.62 |
-29:22:40.1 |
HIP 83258 |
19.28 |
| 2026-10-06 12:00 |
17:00:26.79 |
-29:22:39.2 |
HIP 83258 |
19.19 |
| 2026-10-07 00:00 |
17:00:27.98 |
-29:22:38.3 |
HIP 83258 |
19.10 |
| 2026-10-07 12:00 |
17:00:29.19 |
-29:22:37.5 |
HIP 83258 |
19.02 |
| 2026-10-08 00:00 |
17:00:30.42 |
-29:22:36.8 |
HIP 83258 |
18.93 |
| 2026-10-08 12:00 |
17:00:31.68 |
-29:22:36.0 |
HIP 83258 |
18.85 |
| 2026-10-09 00:00 |
17:00:32.96 |
-29:22:35.4 |
HIP 83258 |
18.76 |
| 2026-10-09 12:00 |
17:00:34.26 |
-29:22:34.8 |
HIP 83258 |
18.68 |
| 2026-10-10 00:00 |
17:00:35.58 |
-29:22:34.2 |
HIP 83258 |
18.60 |
| 2026-10-10 12:00 |
17:00:36.92 |
-29:22:33.7 |
HIP 83258 |
18.52 |
| 2026-10-11 00:00 |
17:00:38.29 |
-29:22:33.2 |
HIP 83258 |
18.45 |