| 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) |
| 2026-06-01 00:00 |
12:59:52.16 |
-08:56:45.4 |
HIP 63486 |
13.08 |
| 2026-06-01 12:00 |
12:59:47.87 |
-08:55:54.4 |
HIP 63486 |
14.43 |
| 2026-06-02 00:00 |
12:59:43.68 |
-08:55:03.9 |
HIP 63362 |
15.29 |
| 2026-06-02 12:00 |
12:59:39.59 |
-08:54:14.1 |
HIP 63362 |
13.99 |
| 2026-06-03 00:00 |
12:59:35.60 |
-08:53:25.0 |
HIP 63362 |
12.72 |
| 2026-06-03 12:00 |
12:59:31.72 |
-08:52:36.4 |
HIP 63362 |
11.47 |
| 2026-06-04 00:00 |
12:59:27.95 |
-08:51:48.5 |
HIP 63362 |
10.25 |
| 2026-06-04 12:00 |
12:59:24.27 |
-08:51:01.3 |
HIP 63362 |
9.05 |
| 2026-06-05 00:00 |
12:59:20.71 |
-08:50:14.7 |
HIP 63362 |
7.89 |
| 2026-06-05 12:00 |
12:59:17.24 |
-08:49:28.7 |
HIP 63362 |
6.75 |
| 2026-06-06 00:00 |
12:59:13.88 |
-08:48:43.4 |
HIP 63362 |
5.64 |
| 2026-06-06 12:00 |
12:59:10.63 |
-08:47:58.7 |
HIP 63362 |
4.56 |
| 2026-06-07 00:00 |
12:59:07.48 |
-08:47:14.7 |
HIP 63362 |
3.51 |
| 2026-06-07 12:00 |
12:59:04.44 |
-08:46:31.4 |
HIP 63362 |
2.50 |
| 2026-06-08 00:00 |
12:59:01.50 |
-08:45:48.7 |
HIP 63362 |
1.56 |
| 2026-06-08 12:00 |
12:58:58.67 |
-08:45:06.7 |
HIP 63362 |
0.82 |
| 2026-06-09 00:00 |
12:58:55.95 |
-08:44:25.3 |
HIP 63362 |
0.90 |
| 2026-06-09 12:00 |
12:58:53.33 |
-08:43:44.6 |
HIP 63362 |
1.65 |
| 2026-06-10 00:00 |
12:58:50.82 |
-08:43:04.6 |
HIP 63362 |
2.50 |
| 2026-06-10 12:00 |
12:58:48.42 |
-08:42:25.3 |
HIP 63362 |
3.36 |
| 2026-06-11 00:00 |
12:58:46.12 |
-08:41:46.6 |
HIP 63362 |
4.19 |
| 2026-06-11 12:00 |
12:58:43.93 |
-08:41:08.6 |
HIP 63362 |
5.01 |
| 2026-06-12 00:00 |
12:58:41.85 |
-08:40:31.3 |
HIP 63362 |
5.81 |
| 2026-06-12 12:00 |
12:58:39.87 |
-08:39:54.7 |
HIP 63362 |
6.58 |
| 2026-06-13 00:00 |
12:58:38.00 |
-08:39:18.7 |
HIP 63362 |
7.32 |
| 2026-06-13 12:00 |
12:58:36.24 |
-08:38:43.5 |
HIP 63362 |
8.04 |
| 2026-06-14 00:00 |
12:58:34.59 |
-08:38:08.9 |
HIP 63362 |
8.74 |
| 2026-06-14 12:00 |
12:58:33.05 |
-08:37:35.0 |
HIP 63362 |
9.41 |
| 2026-06-15 00:00 |
12:58:31.61 |
-08:37:01.8 |
HIP 63362 |
10.05 |
| 2026-06-15 12:00 |
12:58:30.29 |
-08:36:29.3 |
HIP 63362 |
10.67 |
| 2026-06-16 00:00 |
12:58:29.07 |
-08:35:57.5 |
HIP 63362 |
11.27 |
| 2026-06-16 12:00 |
12:58:27.96 |
-08:35:26.4 |
HIP 63362 |
11.84 |
| 2026-06-17 00:00 |
12:58:26.96 |
-08:34:55.9 |
HIP 63362 |
12.38 |
| 2026-06-17 12:00 |
12:58:26.06 |
-08:34:26.2 |
HIP 63362 |
12.90 |
| 2026-06-18 00:00 |
12:58:25.28 |
-08:33:57.2 |
HIP 63362 |
13.40 |
| 2026-06-18 12:00 |
12:58:24.60 |
-08:33:28.8 |
HIP 63362 |
13.87 |
| 2026-06-19 00:00 |
12:58:24.03 |
-08:33:01.2 |
HIP 63362 |
14.32 |
| 2026-06-19 12:00 |
12:58:23.57 |
-08:32:34.2 |
HIP 63362 |
14.75 |
| 2026-06-20 00:00 |
12:58:23.21 |
-08:32:08.0 |
HIP 63362 |
15.15 |
| 2026-06-20 12:00 |
12:58:22.97 |
-08:31:42.4 |
HIP 63362 |
15.53 |
| 2026-06-21 00:00 |
12:58:22.83 |
-08:31:17.6 |
HIP 63362 |
15.89 |
| 2026-06-21 12:00 |
12:58:22.80 |
-08:30:53.4 |
HIP 63362 |
16.23 |
| 2026-06-22 00:00 |
12:58:22.87 |
-08:30:29.9 |
HIP 63362 |
16.54 |