22P/Kopff
| Parameter |
Value |
| Designation |
22P/Kopff |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2022-03-17T21:18:35.899200Z |
| Orbit solution date (soln_date, UTC) |
2026-01-08T08:23:21Z |
| Obs used |
2690 |
| NEO |
- |
| M1 |
11.900 |
| K1 |
9.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-03-03.0000000 |
| e |
0.54862257 |
| q (au) |
1.554732 |
| a (au) |
3.444417 |
| i (deg) |
4.739898 |
| Ω (om, deg) |
120.835441 |
| ω (w, deg) |
162.912936 |
| M (ma, deg) |
188.722339 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.516 + 4.579\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.516 |
| n |
4.579 |
| gf |
1.000 |
| gb |
-0.943 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2020-01-23 |
2022-03-17 |
+4.9846 |
-3.031 |
| 2022-03-23 |
2022-07-08 |
+19.0673 |
-6.276 |
| 2022-07-08 |
2024-04-09 |
+1.5814 |
-1.000 |
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 |
07:41:36.63 |
+21:06:58.6 |
HIP 37540 |
12.35 |
| 2026-02-03 12:00 |
07:41:16.81 |
+21:07:58.2 |
HIP 37540 |
16.59 |
| 2026-02-04 00:00 |
07:40:57.10 |
+21:08:57.4 |
HIP 37442 |
18.23 |
| 2026-02-04 12:00 |
07:40:37.51 |
+21:09:56.2 |
HIP 37442 |
18.77 |
| 2026-02-05 00:00 |
07:40:18.02 |
+21:10:54.5 |
HIP 37442 |
20.38 |
| 2026-02-05 12:00 |
07:39:58.65 |
+21:11:52.5 |
HIP 37298 |
22.63 |
| 2026-02-06 00:00 |
07:39:39.40 |
+21:12:50.0 |
HIP 37298 |
22.56 |
| 2026-02-06 12:00 |
07:39:20.27 |
+21:13:47.1 |
HIP 37298 |
23.41 |
| 2026-02-07 00:00 |
07:39:01.26 |
+21:14:43.7 |
HIP 37298 |
25.05 |
| 2026-02-07 12:00 |
07:38:42.39 |
+21:15:39.9 |
HIP 37084 |
21.73 |
| 2026-02-08 00:00 |
07:38:23.64 |
+21:16:35.7 |
HIP 37084 |
17.30 |
| 2026-02-08 12:00 |
07:38:05.02 |
+21:17:31.0 |
HIP 37084 |
12.92 |
| 2026-02-09 00:00 |
07:37:46.55 |
+21:18:25.9 |
HIP 37084 |
8.62 |
| 2026-02-09 12:00 |
07:37:28.21 |
+21:19:20.3 |
HIP 37084 |
4.56 |
| 2026-02-10 00:00 |
07:37:10.01 |
+21:20:14.2 |
HIP 37084 |
2.30 |
| 2026-02-10 12:00 |
07:36:51.95 |
+21:21:07.7 |
HIP 37084 |
5.20 |
| 2026-02-11 00:00 |
07:36:34.05 |
+21:22:00.7 |
HIP 37084 |
9.22 |
| 2026-02-11 12:00 |
07:36:16.29 |
+21:22:53.2 |
HIP 37084 |
13.36 |
| 2026-02-12 00:00 |
07:35:58.69 |
+21:23:45.3 |
HIP 37084 |
17.50 |
| 2026-02-12 12:00 |
07:35:41.24 |
+21:24:36.9 |
HIP 37084 |
21.62 |
| 2026-02-13 00:00 |
07:35:23.94 |
+21:25:27.9 |
HIP 37084 |
25.72 |
| 2026-02-13 12:00 |
07:35:06.81 |
+21:26:18.5 |
HIP 36789 |
24.42 |
| 2026-02-14 00:00 |
07:34:49.84 |
+21:27:08.7 |
HIP 36789 |
22.84 |
| 2026-02-14 12:00 |
07:34:33.04 |
+21:27:58.3 |
HIP 36789 |
21.91 |
| 2026-02-15 00:00 |
07:34:16.40 |
+21:28:47.4 |
HIP 36789 |
21.69 |
| 2026-02-15 12:00 |
07:33:59.94 |
+21:29:36.0 |
HIP 36663 |
20.52 |
| 2026-02-16 00:00 |
07:33:43.65 |
+21:30:24.1 |
HIP 36663 |
17.14 |
| 2026-02-16 12:00 |
07:33:27.53 |
+21:31:11.8 |
HIP 36663 |
14.05 |
| 2026-02-17 00:00 |
07:33:11.59 |
+21:31:58.9 |
HIP 36663 |
11.43 |
| 2026-02-17 12:00 |
07:32:55.82 |
+21:32:45.5 |
HIP 36663 |
9.65 |
| 2026-02-18 00:00 |
07:32:40.24 |
+21:33:31.6 |
HIP 36663 |
9.15 |
| 2026-02-18 12:00 |
07:32:24.85 |
+21:34:17.1 |
HIP 36663 |
10.07 |
| 2026-02-19 00:00 |
07:32:09.63 |
+21:35:02.2 |
HIP 36663 |
12.05 |
| 2026-02-19 12:00 |
07:31:54.61 |
+21:35:46.7 |
HIP 36663 |
14.63 |
| 2026-02-20 00:00 |
07:31:39.78 |
+21:36:30.8 |
HIP 36663 |
17.53 |
| 2026-02-20 12:00 |
07:31:25.14 |
+21:37:14.3 |
HIP 36663 |
20.58 |
| 2026-02-21 00:00 |
07:31:10.69 |
+21:37:57.2 |
HIP 36663 |
23.71 |
| 2026-02-21 12:00 |
07:30:56.43 |
+21:38:39.7 |
HIP 36663 |
26.87 |
| 2026-02-22 00:00 |
07:30:42.38 |
+21:39:21.6 |
HIP 36663 |
30.03 |
| 2026-02-22 12:00 |
07:30:28.52 |
+21:40:03.0 |
HIP 36307 |
29.61 |
| 2026-02-23 00:00 |
07:30:14.86 |
+21:40:43.9 |
HIP 36307 |
26.73 |
| 2026-02-23 12:00 |
07:30:01.41 |
+21:41:24.3 |
HIP 36307 |
23.98 |
| 2026-02-24 00:00 |
07:29:48.15 |
+21:42:04.1 |
HIP 36307 |
21.40 |