| Parameter |
Value |
| Designation |
391P/Kowalski |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2008-02-19T15:11:16.969920Z |
| Orbit solution date (soln_date, UTC) |
2026-09-08T09:12:27Z |
| Obs used |
264 |
| NEO |
- |
| M1 |
9.900 |
| K1 |
10.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2019-10-22T00:19:10.848000Z |
| Discovery magnitude (MPC) |
20.30 N |
| Discovery observatory (MPC) |
J22 · Tacande Observatory, La Palma |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2009-01-31.0000000 |
| e |
0.11931437 |
| q (au) |
4.119607 |
| a (au) |
4.677728 |
| i (deg) |
21.275374 |
| Ω (om, deg) |
124.763840 |
| ω (w, deg) |
186.849793 |
| M (ma, deg) |
33.743367 |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
15:34:09.58 |
-01:39:22.7 |
HIP 76246 |
13.32 |
| 2026-09-20 12:00 |
15:34:32.32 |
-01:42:38.3 |
HIP 76246 |
15.64 |
| 2026-09-21 00:00 |
15:34:55.18 |
-01:45:53.6 |
HIP 76246 |
19.94 |
| 2026-09-21 12:00 |
15:35:18.16 |
-01:49:08.5 |
HIP 76246 |
25.25 |
| 2026-09-22 00:00 |
15:35:41.25 |
-01:52:23.1 |
HIP 76246 |
31.07 |
| 2026-09-22 12:00 |
15:36:04.46 |
-01:55:37.3 |
HIP 76399 |
35.44 |
| 2026-09-23 00:00 |
15:36:27.79 |
-01:58:51.2 |
HIP 76399 |
32.36 |
| 2026-09-23 12:00 |
15:36:51.23 |
-02:02:04.7 |
HIP 76399 |
30.47 |
| 2026-09-24 00:00 |
15:37:14.78 |
-02:05:17.8 |
HIP 76607 |
28.28 |
| 2026-09-24 12:00 |
15:37:38.45 |
-02:08:30.5 |
HIP 76607 |
26.54 |
| 2026-09-25 00:00 |
15:38:02.23 |
-02:11:42.9 |
HIP 76607 |
26.42 |
| 2026-09-25 12:00 |
15:38:26.12 |
-02:14:54.9 |
HIP 76738 |
27.38 |
| 2026-09-26 00:00 |
15:38:50.13 |
-02:18:06.4 |
HIP 76738 |
21.02 |
| 2026-09-26 12:00 |
15:39:14.24 |
-02:21:17.6 |
HIP 76738 |
15.02 |
| 2026-09-27 00:00 |
15:39:38.46 |
-02:24:28.4 |
HIP 76738 |
10.08 |
| 2026-09-27 12:00 |
15:40:02.80 |
-02:27:38.7 |
HIP 76738 |
8.42 |
| 2026-09-28 00:00 |
15:40:27.24 |
-02:30:48.7 |
HIP 76738 |
11.58 |
| 2026-09-28 12:00 |
15:40:51.79 |
-02:33:58.2 |
HIP 76842 |
9.18 |
| 2026-09-29 00:00 |
15:41:16.44 |
-02:37:07.4 |
HIP 76842 |
2.26 |
| 2026-09-29 12:00 |
15:41:41.21 |
-02:40:16.1 |
HIP 76842 |
4.68 |
| 2026-09-30 00:00 |
15:42:06.08 |
-02:43:24.3 |
HIP 76842 |
11.64 |
| 2026-09-30 12:00 |
15:42:31.05 |
-02:46:32.2 |
HIP 76842 |
18.61 |
| 2026-10-01 00:00 |
15:42:56.13 |
-02:49:39.6 |
HIP 77080 |
23.86 |
| 2026-10-01 12:00 |
15:43:21.32 |
-02:52:46.5 |
HIP 77080 |
16.85 |
| 2026-10-02 00:00 |
15:43:46.60 |
-02:55:53.0 |
HIP 77080 |
9.82 |
| 2026-10-02 12:00 |
15:44:12.00 |
-02:58:59.1 |
HIP 77080 |
2.81 |
| 2026-10-03 00:00 |
15:44:37.49 |
-03:02:04.7 |
HIP 77080 |
4.38 |
| 2026-10-03 12:00 |
15:45:03.09 |
-03:05:09.9 |
HIP 77080 |
11.45 |
| 2026-10-04 00:00 |
15:45:28.78 |
-03:08:14.6 |
HIP 77080 |
18.56 |
| 2026-10-04 12:00 |
15:45:54.58 |
-03:11:18.8 |
HIP 77080 |
25.69 |
| 2026-10-05 00:00 |
15:46:20.48 |
-03:14:22.5 |
HIP 77080 |
32.84 |
| 2026-10-05 12:00 |
15:46:46.48 |
-03:17:25.8 |
HIP 77429 |
31.39 |
| 2026-10-06 00:00 |
15:47:12.58 |
-03:20:28.5 |
HIP 77429 |
29.04 |
| 2026-10-06 12:00 |
15:47:38.77 |
-03:23:30.8 |
HIP 77429 |
28.34 |
| 2026-10-07 00:00 |
15:48:05.07 |
-03:26:32.6 |
HIP 77516 |
23.02 |
| 2026-10-07 12:00 |
15:48:31.46 |
-03:29:33.8 |
HIP 77516 |
16.85 |
| 2026-10-08 00:00 |
15:48:57.94 |
-03:32:34.6 |
HIP 77516 |
11.92 |
| 2026-10-08 12:00 |
15:49:24.53 |
-03:35:34.9 |
HIP 77516 |
10.28 |
| 2026-10-09 00:00 |
15:49:51.20 |
-03:38:34.6 |
HIP 77516 |
13.23 |
| 2026-10-09 12:00 |
15:50:17.97 |
-03:41:33.8 |
HIP 77542 |
14.60 |
| 2026-10-10 00:00 |
15:50:44.84 |
-03:44:32.5 |
HIP 77542 |
15.91 |
| 2026-10-10 12:00 |
15:51:11.80 |
-03:47:30.6 |
HIP 77542 |
20.03 |
| 2026-10-11 00:00 |
15:51:38.84 |
-03:50:28.2 |
HIP 77542 |
25.67 |