| Parameter |
Value |
| Designation |
99P/Kowal 1 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2022-04-08T09:21:18.054720Z |
| Orbit solution date (soln_date, UTC) |
2024-08-26T13:15:15Z |
| Obs used |
1698 |
| NEO |
- |
| M1 |
6.700 |
| K1 |
12.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-12-29.0000000 |
| e |
0.22969880 |
| q (au) |
4.725879 |
| a (au) |
6.135105 |
| i (deg) |
4.337500 |
| Ω (om, deg) |
28.179464 |
| ω (w, deg) |
174.192344 |
| M (ma, deg) |
187.644015 |
Magnitude
Scatter + Global Linear
$$
M_a = (3.594 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
3.594 |
| n |
6.000 |
| gf |
0.995 |
| gb |
-0.500 |
| 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 |
| 2019-10-08 |
2022-04-08 |
+13.7752 |
-9.355 |
| 2022-04-08 |
2024-07-25 |
-7.7771 |
+5.047 |
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 |
22:32:07.10 |
-13:27:24.1 |
HIP 111234 |
8.47 |
| 2026-06-01 12:00 |
22:32:11.99 |
-13:27:10.7 |
HIP 111234 |
8.70 |
| 2026-06-02 00:00 |
22:32:16.75 |
-13:26:58.2 |
HIP 111234 |
9.06 |
| 2026-06-02 12:00 |
22:32:21.38 |
-13:26:46.5 |
HIP 111234 |
9.54 |
| 2026-06-03 00:00 |
22:32:25.86 |
-13:26:35.5 |
HIP 111234 |
10.09 |
| 2026-06-03 12:00 |
22:32:30.22 |
-13:26:25.4 |
HIP 111234 |
10.70 |
| 2026-06-04 00:00 |
22:32:34.43 |
-13:26:16.0 |
HIP 111234 |
11.35 |
| 2026-06-04 12:00 |
22:32:38.51 |
-13:26:07.5 |
HIP 111234 |
12.03 |
| 2026-06-05 00:00 |
22:32:42.45 |
-13:25:59.7 |
HIP 111234 |
12.72 |
| 2026-06-05 12:00 |
22:32:46.26 |
-13:25:52.8 |
HIP 111234 |
13.41 |
| 2026-06-06 00:00 |
22:32:49.92 |
-13:25:46.6 |
HIP 111234 |
14.09 |
| 2026-06-06 12:00 |
22:32:53.45 |
-13:25:41.3 |
HIP 111234 |
14.77 |
| 2026-06-07 00:00 |
22:32:56.84 |
-13:25:36.7 |
HIP 111234 |
15.42 |
| 2026-06-07 12:00 |
22:33:00.10 |
-13:25:33.0 |
HIP 111234 |
16.06 |
| 2026-06-08 00:00 |
22:33:03.21 |
-13:25:30.1 |
HIP 111234 |
16.68 |
| 2026-06-08 12:00 |
22:33:06.18 |
-13:25:28.0 |
HIP 111234 |
17.27 |
| 2026-06-09 00:00 |
22:33:09.02 |
-13:25:26.6 |
HIP 111234 |
17.84 |
| 2026-06-09 12:00 |
22:33:11.71 |
-13:25:26.1 |
HIP 111234 |
18.38 |
| 2026-06-10 00:00 |
22:33:14.26 |
-13:25:26.4 |
HIP 111234 |
18.89 |
| 2026-06-10 12:00 |
22:33:16.68 |
-13:25:27.6 |
HIP 111234 |
19.38 |
| 2026-06-11 00:00 |
22:33:18.95 |
-13:25:29.5 |
HIP 111234 |
19.83 |
| 2026-06-11 12:00 |
22:33:21.08 |
-13:25:32.2 |
HIP 111234 |
20.25 |
| 2026-06-12 00:00 |
22:33:23.07 |
-13:25:35.8 |
HIP 111234 |
20.64 |
| 2026-06-12 12:00 |
22:33:24.92 |
-13:25:40.1 |
HIP 111234 |
20.99 |
| 2026-06-13 00:00 |
22:33:26.62 |
-13:25:45.3 |
HIP 111234 |
21.31 |
| 2026-06-13 12:00 |
22:33:28.19 |
-13:25:51.3 |
HIP 111234 |
21.60 |
| 2026-06-14 00:00 |
22:33:29.61 |
-13:25:58.1 |
HIP 111234 |
21.86 |
| 2026-06-14 12:00 |
22:33:30.89 |
-13:26:05.7 |
HIP 111234 |
22.08 |
| 2026-06-15 00:00 |
22:33:32.02 |
-13:26:14.1 |
HIP 111234 |
22.27 |
| 2026-06-15 12:00 |
22:33:33.01 |
-13:26:23.4 |
HIP 111234 |
22.42 |
| 2026-06-16 00:00 |
22:33:33.87 |
-13:26:33.4 |
HIP 111234 |
22.54 |
| 2026-06-16 12:00 |
22:33:34.57 |
-13:26:44.2 |
HIP 111234 |
22.62 |
| 2026-06-17 00:00 |
22:33:35.14 |
-13:26:55.9 |
HIP 111234 |
22.67 |
| 2026-06-17 12:00 |
22:33:35.56 |
-13:27:08.3 |
HIP 111234 |
22.68 |
| 2026-06-18 00:00 |
22:33:35.84 |
-13:27:21.5 |
HIP 111234 |
22.66 |
| 2026-06-18 12:00 |
22:33:35.98 |
-13:27:35.6 |
HIP 111234 |
22.61 |
| 2026-06-19 00:00 |
22:33:35.97 |
-13:27:50.4 |
HIP 111234 |
22.52 |
| 2026-06-19 12:00 |
22:33:35.82 |
-13:28:06.0 |
HIP 111234 |
22.39 |
| 2026-06-20 00:00 |
22:33:35.53 |
-13:28:22.4 |
HIP 111234 |
22.23 |
| 2026-06-20 12:00 |
22:33:35.10 |
-13:28:39.6 |
HIP 111234 |
22.04 |
| 2026-06-21 00:00 |
22:33:34.52 |
-13:28:57.6 |
HIP 111234 |
21.81 |
| 2026-06-21 12:00 |
22:33:33.81 |
-13:29:16.3 |
HIP 111234 |
21.54 |
| 2026-06-22 00:00 |
22:33:32.95 |
-13:29:35.9 |
HIP 111234 |
21.25 |