| Parameter |
Value |
| Designation |
104P/Kowal 2 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2022-01-11T14:49:09.753600Z |
| Orbit solution date (soln_date, UTC) |
2023-04-05T03:16:58Z |
| Obs used |
1551 |
| NEO |
Yes |
| M1 |
14.600 |
| K1 |
12.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-09-29.0000000 |
| e |
0.66545272 |
| q (au) |
1.073098 |
| a (au) |
3.207614 |
| i (deg) |
5.701090 |
| Ω (om, deg) |
207.213526 |
| ω (w, deg) |
227.245888 |
| M (ma, deg) |
342.051208 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.882 + 3.137\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.882 |
| n |
3.137 |
| gf |
1.000 |
| gb |
-0.998 |
| 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 |
| 2021-08-11 |
2021-11-29 |
+3.2064 |
+1.741 |
| 2021-11-29 |
2022-01-11 |
+71.5132 |
-3.914 |
| 2022-01-11 |
2022-07-20 |
-2.8823 |
-1.387 |
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 |
18:53:10.50 |
-15:25:57.4 |
HIP 92660 |
7.16 |
| 2026-07-29 12:00 |
18:52:46.51 |
-15:26:48.5 |
HIP 92660 |
7.37 |
| 2026-07-30 00:00 |
18:52:22.66 |
-15:27:39.8 |
HIP 92660 |
11.19 |
| 2026-07-30 12:00 |
18:51:58.95 |
-15:28:31.2 |
HIP 92660 |
16.21 |
| 2026-07-31 00:00 |
18:51:35.40 |
-15:29:22.9 |
HIP 92660 |
21.58 |
| 2026-07-31 12:00 |
18:51:11.99 |
-15:30:14.8 |
HIP 92660 |
27.07 |
| 2026-08-01 00:00 |
18:50:48.74 |
-15:31:06.8 |
HIP 92660 |
32.60 |
| 2026-08-01 12:00 |
18:50:25.65 |
-15:31:59.0 |
HIP 92292 |
29.80 |
| 2026-08-02 00:00 |
18:50:02.73 |
-15:32:51.4 |
HIP 92292 |
25.59 |
| 2026-08-02 12:00 |
18:49:39.97 |
-15:33:44.0 |
HIP 92292 |
22.04 |
| 2026-08-03 00:00 |
18:49:17.38 |
-15:34:36.7 |
HIP 92292 |
19.48 |
| 2026-08-03 12:00 |
18:48:54.96 |
-15:35:29.6 |
HIP 92292 |
18.29 |
| 2026-08-04 00:00 |
18:48:32.73 |
-15:36:22.7 |
HIP 92292 |
18.69 |
| 2026-08-04 12:00 |
18:48:10.67 |
-15:37:15.9 |
HIP 92292 |
20.56 |
| 2026-08-05 00:00 |
18:47:48.80 |
-15:38:09.2 |
HIP 92205 |
21.30 |
| 2026-08-05 12:00 |
18:47:27.12 |
-15:39:02.7 |
HIP 92205 |
19.99 |
| 2026-08-06 00:00 |
18:47:05.63 |
-15:39:56.3 |
HIP 92090 |
18.36 |
| 2026-08-06 12:00 |
18:46:44.34 |
-15:40:50.0 |
HIP 92090 |
15.39 |
| 2026-08-07 00:00 |
18:46:23.24 |
-15:41:43.8 |
HIP 92090 |
13.82 |
| 2026-08-07 12:00 |
18:46:02.35 |
-15:42:37.8 |
HIP 92090 |
14.09 |
| 2026-08-08 00:00 |
18:45:41.66 |
-15:43:31.9 |
HIP 92090 |
16.05 |
| 2026-08-08 12:00 |
18:45:21.18 |
-15:44:26.1 |
HIP 92090 |
19.16 |
| 2026-08-09 00:00 |
18:45:00.92 |
-15:45:20.4 |
HIP 91976 |
19.74 |
| 2026-08-09 12:00 |
18:44:40.87 |
-15:46:14.7 |
HIP 91976 |
18.79 |
| 2026-08-10 00:00 |
18:44:21.04 |
-15:47:09.2 |
HIP 91976 |
19.07 |
| 2026-08-10 12:00 |
18:44:01.43 |
-15:48:03.8 |
HIP 91976 |
20.50 |
| 2026-08-11 00:00 |
18:43:42.05 |
-15:48:58.4 |
HIP 91725 |
20.69 |
| 2026-08-11 12:00 |
18:43:22.89 |
-15:49:53.1 |
HIP 91725 |
16.02 |
| 2026-08-12 00:00 |
18:43:03.97 |
-15:50:47.9 |
HIP 91725 |
11.41 |
| 2026-08-12 12:00 |
18:42:45.28 |
-15:51:42.7 |
HIP 91725 |
6.91 |
| 2026-08-13 00:00 |
18:42:26.83 |
-15:52:37.6 |
HIP 91725 |
2.78 |
| 2026-08-13 12:00 |
18:42:08.62 |
-15:53:32.5 |
HIP 91725 |
2.91 |
| 2026-08-14 00:00 |
18:41:50.65 |
-15:54:27.5 |
HIP 91725 |
6.97 |
| 2026-08-14 12:00 |
18:41:32.93 |
-15:55:22.5 |
HIP 91725 |
11.24 |
| 2026-08-15 00:00 |
18:41:15.46 |
-15:56:17.5 |
HIP 91725 |
15.50 |
| 2026-08-15 12:00 |
18:40:58.23 |
-15:57:12.6 |
HIP 91725 |
19.73 |
| 2026-08-16 00:00 |
18:40:41.26 |
-15:58:07.6 |
HIP 91725 |
23.90 |
| 2026-08-16 12:00 |
18:40:24.55 |
-15:59:02.7 |
HIP 91725 |
28.01 |
| 2026-08-17 00:00 |
18:40:08.09 |
-15:59:57.8 |
HIP 91414 |
28.78 |
| 2026-08-17 12:00 |
18:39:51.89 |
-16:00:52.9 |
HIP 91414 |
25.28 |
| 2026-08-18 00:00 |
18:39:35.95 |
-16:01:48.0 |
HIP 91414 |
22.00 |
| 2026-08-18 12:00 |
18:39:20.28 |
-16:02:43.1 |
HIP 91414 |
19.01 |
| 2026-08-19 00:00 |
18:39:04.87 |
-16:03:38.2 |
HIP 91414 |
16.42 |