| Parameter |
Value |
| Designation |
158P/Kowal-LINEAR |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-09-25T04:18:05.472000Z |
| Orbit solution date (soln_date, UTC) |
2025-02-13T09:13:06Z |
| Obs used |
1093 |
| NEO |
- |
| M1 |
7.100 |
| K1 |
13.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-07-12.0000000 |
| e |
0.03060860 |
| q (au) |
4.576459 |
| a (au) |
4.720961 |
| i (deg) |
7.907531 |
| Ω (om, deg) |
137.306066 |
| ω (w, deg) |
232.612379 |
| M (ma, deg) |
352.776355 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.344 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.344 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.957 |
| 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 |
| 2018-02-14 |
2025-01-25 |
+18.3296 |
-12.712 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
06:32:09.57 |
+20:58:21.0 |
HIP 31172 |
28.51 |
| 2026-05-12 12:00 |
06:32:30.69 |
+20:58:25.4 |
HIP 31172 |
28.22 |
| 2026-05-13 00:00 |
06:32:51.88 |
+20:58:29.4 |
HIP 31327 |
25.37 |
| 2026-05-13 12:00 |
06:33:13.15 |
+20:58:33.1 |
HIP 31327 |
22.17 |
| 2026-05-14 00:00 |
06:33:34.49 |
+20:58:36.4 |
HIP 31327 |
19.71 |
| 2026-05-14 12:00 |
06:33:55.91 |
+20:58:39.5 |
HIP 31327 |
18.31 |
| 2026-05-15 00:00 |
06:34:17.41 |
+20:58:42.2 |
HIP 31327 |
18.21 |
| 2026-05-15 12:00 |
06:34:38.98 |
+20:58:44.6 |
HIP 31483 |
14.51 |
| 2026-05-16 00:00 |
06:35:00.63 |
+20:58:46.6 |
HIP 31483 |
10.02 |
| 2026-05-16 12:00 |
06:35:22.35 |
+20:58:48.3 |
HIP 31483 |
6.41 |
| 2026-05-17 00:00 |
06:35:44.14 |
+20:58:49.7 |
HIP 31483 |
5.76 |
| 2026-05-17 12:00 |
06:36:06.00 |
+20:58:50.7 |
HIP 31483 |
8.79 |
| 2026-05-18 00:00 |
06:36:27.93 |
+20:58:51.4 |
HIP 31483 |
13.19 |
| 2026-05-18 12:00 |
06:36:49.93 |
+20:58:51.8 |
HIP 31483 |
17.98 |
| 2026-05-19 00:00 |
06:37:12.00 |
+20:58:51.8 |
HIP 31483 |
22.94 |
| 2026-05-19 12:00 |
06:37:34.14 |
+20:58:51.4 |
HIP 31483 |
27.98 |
| 2026-05-20 00:00 |
06:37:56.34 |
+20:58:50.8 |
HIP 31483 |
33.08 |
| 2026-05-20 12:00 |
06:38:18.61 |
+20:58:49.8 |
HIP 31483 |
38.21 |
| 2026-05-21 00:00 |
06:38:40.94 |
+20:58:48.4 |
HIP 31987 |
38.85 |
| 2026-05-21 12:00 |
06:39:03.34 |
+20:58:46.8 |
HIP 31987 |
34.46 |
| 2026-05-22 00:00 |
06:39:25.80 |
+20:58:44.7 |
HIP 31987 |
30.32 |
| 2026-05-22 12:00 |
06:39:48.32 |
+20:58:42.4 |
HIP 31987 |
26.57 |
| 2026-05-23 00:00 |
06:40:10.90 |
+20:58:39.7 |
HIP 31987 |
23.39 |
| 2026-05-23 12:00 |
06:40:33.55 |
+20:58:36.6 |
HIP 31987 |
21.06 |
| 2026-05-24 00:00 |
06:40:56.25 |
+20:58:33.2 |
HIP 31987 |
19.89 |
| 2026-05-24 12:00 |
06:41:19.01 |
+20:58:29.5 |
HIP 31987 |
20.10 |
| 2026-05-25 00:00 |
06:41:41.83 |
+20:58:25.4 |
HIP 32180 |
20.11 |
| 2026-05-25 12:00 |
06:42:04.71 |
+20:58:21.0 |
HIP 32180 |
14.80 |
| 2026-05-26 00:00 |
06:42:27.64 |
+20:58:16.2 |
HIP 32180 |
9.51 |
| 2026-05-26 12:00 |
06:42:50.63 |
+20:58:11.1 |
HIP 32180 |
4.35 |
| 2026-05-27 00:00 |
06:43:13.67 |
+20:58:05.6 |
HIP 32180 |
2.26 |
| 2026-05-27 12:00 |
06:43:36.77 |
+20:57:59.8 |
HIP 32180 |
7.03 |
| 2026-05-28 00:00 |
06:43:59.92 |
+20:57:53.7 |
HIP 32180 |
12.33 |
| 2026-05-28 12:00 |
06:44:23.12 |
+20:57:47.2 |
HIP 32329 |
9.63 |
| 2026-05-29 00:00 |
06:44:46.38 |
+20:57:40.3 |
HIP 32329 |
6.35 |
| 2026-05-29 12:00 |
06:45:09.69 |
+20:57:33.2 |
HIP 32329 |
6.85 |
| 2026-05-30 00:00 |
06:45:33.04 |
+20:57:25.6 |
HIP 32329 |
10.63 |
| 2026-05-30 12:00 |
06:45:56.45 |
+20:57:17.8 |
HIP 32459 |
10.06 |
| 2026-05-31 00:00 |
06:46:19.91 |
+20:57:09.5 |
HIP 32459 |
6.86 |
| 2026-05-31 12:00 |
06:46:43.41 |
+20:57:01.0 |
HIP 32459 |
7.27 |
| 2026-06-01 00:00 |
06:47:06.96 |
+20:56:52.1 |
HIP 32459 |
10.91 |
| 2026-06-01 12:00 |
06:47:30.56 |
+20:56:42.8 |
HIP 32459 |
15.69 |
| 2026-06-02 00:00 |
06:47:54.21 |
+20:56:33.2 |
HIP 32459 |
20.84 |