| Parameter |
Value |
| Designation |
391P/Kowalski |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2008-02-19T21:01:27.626880Z |
| Orbit solution date (soln_date, UTC) |
2026-05-28T12:12:26Z |
| Obs used |
261 |
| 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) |
2008-11-18.0000000 |
| e |
0.11956279 |
| q (au) |
4.119554 |
| a (au) |
4.678987 |
| i (deg) |
21.275094 |
| Ω (om, deg) |
124.763090 |
| ω (w, deg) |
186.875752 |
| M (ma, deg) |
26.499836 |
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) |
| 2026-06-01 00:00 |
15:18:41.66 |
+08:17:22.0 |
HIP 74903 |
28.26 |
| 2026-06-01 12:00 |
15:18:26.50 |
+08:16:47.5 |
HIP 74903 |
28.60 |
| 2026-06-02 00:00 |
15:18:11.45 |
+08:16:11.1 |
HIP 74832 |
26.91 |
| 2026-06-02 12:00 |
15:17:56.50 |
+08:15:32.7 |
HIP 74832 |
25.34 |
| 2026-06-03 00:00 |
15:17:41.65 |
+08:14:52.4 |
HIP 74832 |
24.23 |
| 2026-06-03 12:00 |
15:17:26.92 |
+08:14:10.2 |
HIP 74832 |
23.62 |
| 2026-06-04 00:00 |
15:17:12.30 |
+08:13:26.0 |
HIP 74832 |
23.55 |
| 2026-06-04 12:00 |
15:16:57.79 |
+08:12:39.9 |
HIP 74832 |
24.02 |
| 2026-06-05 00:00 |
15:16:43.41 |
+08:11:51.8 |
HIP 74832 |
24.97 |
| 2026-06-05 12:00 |
15:16:29.14 |
+08:11:01.9 |
HIP 74632 |
22.79 |
| 2026-06-06 00:00 |
15:16:14.99 |
+08:10:10.0 |
HIP 74632 |
19.29 |
| 2026-06-06 12:00 |
15:16:00.96 |
+08:09:16.2 |
HIP 74632 |
15.85 |
| 2026-06-07 00:00 |
15:15:47.07 |
+08:08:20.5 |
HIP 74632 |
12.54 |
| 2026-06-07 12:00 |
15:15:33.30 |
+08:07:22.9 |
HIP 74632 |
9.46 |
| 2026-06-08 00:00 |
15:15:19.66 |
+08:06:23.4 |
HIP 74632 |
6.87 |
| 2026-06-08 12:00 |
15:15:06.16 |
+08:05:22.0 |
HIP 74632 |
5.49 |
| 2026-06-09 00:00 |
15:14:52.79 |
+08:04:18.7 |
HIP 74632 |
6.16 |
| 2026-06-09 12:00 |
15:14:39.55 |
+08:03:13.6 |
HIP 74632 |
8.36 |
| 2026-06-10 00:00 |
15:14:26.46 |
+08:02:06.6 |
HIP 74632 |
11.21 |
| 2026-06-10 12:00 |
15:14:13.51 |
+08:00:57.7 |
HIP 74632 |
14.31 |
| 2026-06-11 00:00 |
15:14:00.71 |
+07:59:47.0 |
HIP 74632 |
17.52 |
| 2026-06-11 12:00 |
15:13:48.05 |
+07:58:34.4 |
HIP 74523 |
17.30 |
| 2026-06-12 00:00 |
15:13:35.54 |
+07:57:20.0 |
HIP 74523 |
16.13 |
| 2026-06-12 12:00 |
15:13:23.18 |
+07:56:03.8 |
HIP 74523 |
15.56 |
| 2026-06-13 00:00 |
15:13:10.97 |
+07:54:45.7 |
HIP 74523 |
15.64 |
| 2026-06-13 12:00 |
15:12:58.91 |
+07:53:25.8 |
HIP 74523 |
16.35 |
| 2026-06-14 00:00 |
15:12:47.02 |
+07:52:04.2 |
HIP 74523 |
17.59 |
| 2026-06-14 12:00 |
15:12:35.28 |
+07:50:40.7 |
HIP 74523 |
19.26 |
| 2026-06-15 00:00 |
15:12:23.70 |
+07:49:15.5 |
HIP 74523 |
21.24 |
| 2026-06-15 12:00 |
15:12:12.29 |
+07:47:48.4 |
HIP 74523 |
23.44 |
| 2026-06-16 00:00 |
15:12:01.04 |
+07:46:19.7 |
HIP 74283 |
24.03 |
| 2026-06-16 12:00 |
15:11:49.96 |
+07:44:49.2 |
HIP 74283 |
23.33 |
| 2026-06-17 00:00 |
15:11:39.04 |
+07:43:16.9 |
HIP 74283 |
23.09 |
| 2026-06-17 12:00 |
15:11:28.30 |
+07:41:42.9 |
HIP 74288 |
23.30 |
| 2026-06-18 00:00 |
15:11:17.73 |
+07:40:07.2 |
HIP 74288 |
21.09 |
| 2026-06-18 12:00 |
15:11:07.33 |
+07:38:29.8 |
HIP 74288 |
19.11 |
| 2026-06-19 00:00 |
15:10:57.10 |
+07:36:50.8 |
HIP 74288 |
17.40 |
| 2026-06-19 12:00 |
15:10:47.05 |
+07:35:10.0 |
HIP 74288 |
16.04 |
| 2026-06-20 00:00 |
15:10:37.18 |
+07:33:27.6 |
HIP 74288 |
15.13 |
| 2026-06-20 12:00 |
15:10:27.48 |
+07:31:43.6 |
HIP 74288 |
14.73 |
| 2026-06-21 00:00 |
15:10:17.97 |
+07:29:58.0 |
HIP 74288 |
14.86 |
| 2026-06-21 12:00 |
15:10:08.64 |
+07:28:10.7 |
HIP 74288 |
15.51 |
| 2026-06-22 00:00 |
15:09:59.49 |
+07:26:21.8 |
HIP 74288 |
16.61 |