99P/Kowal 1
| 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 |
0.994 |
| 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) |
| 2026-02-03 00:00 |
21:28:33.87 |
-18:35:50.3 |
HIP 106027 |
4.23 |
| 2026-02-03 12:00 |
21:28:55.91 |
-18:34:02.7 |
HIP 106027 |
8.38 |
| 2026-02-04 00:00 |
21:29:17.94 |
-18:32:15.1 |
HIP 106027 |
13.55 |
| 2026-02-04 12:00 |
21:29:39.96 |
-18:30:27.4 |
HIP 106126 |
9.78 |
| 2026-02-05 00:00 |
21:30:01.99 |
-18:28:39.7 |
HIP 106126 |
8.18 |
| 2026-02-05 12:00 |
21:30:24.00 |
-18:26:51.9 |
HIP 106126 |
9.96 |
| 2026-02-06 00:00 |
21:30:46.02 |
-18:25:04.1 |
HIP 106126 |
13.87 |
| 2026-02-06 12:00 |
21:31:08.03 |
-18:23:16.3 |
HIP 106126 |
18.62 |
| 2026-02-07 00:00 |
21:31:30.03 |
-18:21:28.5 |
HIP 106382 |
22.92 |
| 2026-02-07 12:00 |
21:31:52.03 |
-18:19:40.6 |
HIP 106382 |
20.21 |
| 2026-02-08 00:00 |
21:32:14.01 |
-18:17:52.7 |
HIP 106382 |
18.77 |
| 2026-02-08 12:00 |
21:32:36.00 |
-18:16:04.8 |
HIP 106382 |
18.90 |
| 2026-02-09 00:00 |
21:32:57.97 |
-18:14:16.8 |
HIP 106415 |
20.10 |
| 2026-02-09 12:00 |
21:33:19.93 |
-18:12:28.9 |
HIP 106415 |
21.65 |
| 2026-02-10 00:00 |
21:33:41.88 |
-18:10:40.9 |
HIP 106470 |
18.76 |
| 2026-02-10 12:00 |
21:34:03.83 |
-18:08:52.9 |
HIP 106470 |
16.99 |
| 2026-02-11 00:00 |
21:34:25.76 |
-18:07:04.9 |
HIP 106470 |
16.92 |
| 2026-02-11 12:00 |
21:34:47.68 |
-18:05:17.0 |
HIP 106522 |
16.87 |
| 2026-02-12 00:00 |
21:35:09.58 |
-18:03:29.0 |
HIP 106522 |
17.13 |
| 2026-02-12 12:00 |
21:35:31.48 |
-18:01:41.0 |
HIP 106522 |
19.05 |
| 2026-02-13 00:00 |
21:35:53.36 |
-17:59:53.1 |
HIP 106522 |
22.20 |
| 2026-02-13 12:00 |
21:36:15.22 |
-17:58:05.1 |
HIP 106673 |
25.50 |
| 2026-02-14 00:00 |
21:36:37.07 |
-17:56:17.2 |
HIP 106673 |
27.47 |
| 2026-02-14 12:00 |
21:36:58.91 |
-17:54:29.3 |
HIP 106673 |
30.32 |
| 2026-02-15 00:00 |
21:37:20.73 |
-17:52:41.5 |
HIP 106741 |
33.76 |
| 2026-02-15 12:00 |
21:37:42.53 |
-17:50:53.6 |
HIP 106741 |
35.92 |
| 2026-02-16 00:00 |
21:38:04.31 |
-17:49:05.8 |
HIP 106805 |
36.57 |
| 2026-02-16 12:00 |
21:38:26.08 |
-17:47:18.1 |
HIP 107027 |
32.36 |
| 2026-02-17 00:00 |
21:38:47.82 |
-17:45:30.4 |
HIP 107027 |
26.88 |
| 2026-02-17 12:00 |
21:39:09.55 |
-17:43:42.7 |
HIP 107027 |
21.41 |
| 2026-02-18 00:00 |
21:39:31.25 |
-17:41:55.1 |
HIP 107027 |
15.94 |
| 2026-02-18 12:00 |
21:39:52.93 |
-17:40:07.5 |
HIP 107027 |
10.48 |
| 2026-02-19 00:00 |
21:40:14.60 |
-17:38:20.0 |
HIP 107027 |
5.04 |
| 2026-02-19 12:00 |
21:40:36.23 |
-17:36:32.6 |
HIP 107027 |
0.86 |
| 2026-02-20 00:00 |
21:40:57.85 |
-17:34:45.2 |
HIP 107027 |
5.96 |
| 2026-02-20 12:00 |
21:41:19.44 |
-17:32:57.9 |
HIP 107027 |
11.39 |
| 2026-02-21 00:00 |
21:41:41.00 |
-17:31:10.7 |
HIP 107027 |
16.83 |
| 2026-02-21 12:00 |
21:42:02.54 |
-17:29:23.5 |
HIP 107122 |
16.11 |
| 2026-02-22 00:00 |
21:42:24.06 |
-17:27:36.5 |
HIP 107122 |
15.56 |
| 2026-02-22 12:00 |
21:42:45.55 |
-17:25:49.5 |
HIP 107263 |
11.47 |
| 2026-02-23 00:00 |
21:43:07.00 |
-17:24:02.6 |
HIP 107263 |
6.11 |
| 2026-02-23 12:00 |
21:43:28.44 |
-17:22:15.9 |
HIP 107263 |
1.33 |
| 2026-02-24 00:00 |
21:43:49.84 |
-17:20:29.2 |
HIP 107263 |
4.98 |