| Parameter |
Value |
| Designation |
425P/Kowalski |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-09-21T00:11:04.882560Z |
| Orbit solution date (soln_date, UTC) |
2024-02-01T00:43:56Z |
| Obs used |
427 |
| NEO |
- |
| M1 |
7.100 |
| K1 |
20.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2021-07-20T14:22:26.860800Z |
| Discovery magnitude (MPC) |
20.36 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-07-26.0000000 |
| e |
0.54240402 |
| q (au) |
2.901345 |
| a (au) |
6.340409 |
| i (deg) |
16.427088 |
| Ω (om, deg) |
210.335779 |
| ω (w, deg) |
200.221889 |
| M (ma, deg) |
266.286495 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.353 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.353 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.633 |
| k |
0.800 |
| 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 |
| 2020-08-19 |
2021-09-16 |
+11.9451 |
-5.152 |
| 2021-09-30 |
2023-01-25 |
-3.5885 |
+1.530 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
13:03:09.28 |
-08:32:24.8 |
HIP 63818 |
24.23 |
| 2026-07-29 12:00 |
13:03:16.64 |
-08:32:49.6 |
HIP 63818 |
22.38 |
| 2026-07-30 00:00 |
13:03:24.08 |
-08:33:15.0 |
HIP 63818 |
20.52 |
| 2026-07-30 12:00 |
13:03:31.61 |
-08:33:41.0 |
HIP 63818 |
18.64 |
| 2026-07-31 00:00 |
13:03:39.22 |
-08:34:07.4 |
HIP 63818 |
16.75 |
| 2026-07-31 12:00 |
13:03:46.91 |
-08:34:34.5 |
HIP 63818 |
14.86 |
| 2026-08-01 00:00 |
13:03:54.68 |
-08:35:02.0 |
HIP 63818 |
12.95 |
| 2026-08-01 12:00 |
13:04:02.53 |
-08:35:30.2 |
HIP 63818 |
11.06 |
| 2026-08-02 00:00 |
13:04:10.46 |
-08:35:58.8 |
HIP 63818 |
9.19 |
| 2026-08-02 12:00 |
13:04:18.47 |
-08:36:28.0 |
HIP 63818 |
7.39 |
| 2026-08-03 00:00 |
13:04:26.57 |
-08:36:57.7 |
HIP 63818 |
5.73 |
| 2026-08-03 12:00 |
13:04:34.74 |
-08:37:27.9 |
HIP 63818 |
4.41 |
| 2026-08-04 00:00 |
13:04:42.98 |
-08:37:58.7 |
HIP 63818 |
3.85 |
| 2026-08-04 12:00 |
13:04:51.31 |
-08:38:30.0 |
HIP 63818 |
4.37 |
| 2026-08-05 00:00 |
13:04:59.71 |
-08:39:01.8 |
HIP 63818 |
5.71 |
| 2026-08-05 12:00 |
13:05:08.20 |
-08:39:34.1 |
HIP 63818 |
7.46 |
| 2026-08-06 00:00 |
13:05:16.75 |
-08:40:07.0 |
HIP 63818 |
9.40 |
| 2026-08-06 12:00 |
13:05:25.39 |
-08:40:40.3 |
HIP 63818 |
11.45 |
| 2026-08-07 00:00 |
13:05:34.10 |
-08:41:14.2 |
HIP 63818 |
13.57 |
| 2026-08-07 12:00 |
13:05:42.89 |
-08:41:48.6 |
HIP 63818 |
15.74 |
| 2026-08-08 00:00 |
13:05:51.75 |
-08:42:23.4 |
HIP 63931 |
17.53 |
| 2026-08-08 12:00 |
13:06:00.69 |
-08:42:58.8 |
HIP 63931 |
17.70 |
| 2026-08-09 00:00 |
13:06:09.70 |
-08:43:34.7 |
HIP 63931 |
18.17 |
| 2026-08-09 12:00 |
13:06:18.78 |
-08:44:11.1 |
HIP 63931 |
18.92 |
| 2026-08-10 00:00 |
13:06:27.94 |
-08:44:47.9 |
HIP 63931 |
19.93 |
| 2026-08-10 12:00 |
13:06:37.17 |
-08:45:25.3 |
HIP 63931 |
21.16 |
| 2026-08-11 00:00 |
13:06:46.48 |
-08:46:03.1 |
HIP 63931 |
22.59 |
| 2026-08-11 12:00 |
13:06:55.86 |
-08:46:41.4 |
HIP 63931 |
24.19 |
| 2026-08-12 00:00 |
13:07:05.31 |
-08:47:20.2 |
HIP 64122 |
24.52 |
| 2026-08-12 12:00 |
13:07:14.83 |
-08:47:59.5 |
HIP 64122 |
22.14 |
| 2026-08-13 00:00 |
13:07:24.42 |
-08:48:39.2 |
HIP 64122 |
19.77 |
| 2026-08-13 12:00 |
13:07:34.08 |
-08:49:19.4 |
HIP 64122 |
17.40 |
| 2026-08-14 00:00 |
13:07:43.81 |
-08:50:00.1 |
HIP 64122 |
15.05 |
| 2026-08-14 12:00 |
13:07:53.61 |
-08:50:41.2 |
HIP 64122 |
12.74 |
| 2026-08-15 00:00 |
13:08:03.47 |
-08:51:22.8 |
HIP 64122 |
10.50 |
| 2026-08-15 12:00 |
13:08:13.41 |
-08:52:04.8 |
HIP 64122 |
8.42 |
| 2026-08-16 00:00 |
13:08:23.41 |
-08:52:47.3 |
HIP 64122 |
6.65 |
| 2026-08-16 12:00 |
13:08:33.48 |
-08:53:30.2 |
HIP 64122 |
5.56 |
| 2026-08-17 00:00 |
13:08:43.62 |
-08:54:13.5 |
HIP 64122 |
5.56 |
| 2026-08-17 12:00 |
13:08:53.82 |
-08:54:57.3 |
HIP 64122 |
6.67 |
| 2026-08-18 00:00 |
13:09:04.09 |
-08:55:41.5 |
HIP 64122 |
8.50 |
| 2026-08-18 12:00 |
13:09:14.42 |
-08:56:26.2 |
HIP 64122 |
10.68 |
| 2026-08-19 00:00 |
13:09:24.82 |
-08:57:11.3 |
HIP 64122 |
13.06 |