| 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) |
| 2026-03-26 00:00 |
06:06:53.82 |
+20:30:46.3 |
HIP 28965 |
13.24 |
| 2026-03-26 12:00 |
06:07:03.80 |
+20:31:14.3 |
HIP 28965 |
13.40 |
| 2026-03-27 00:00 |
06:07:13.93 |
+20:31:42.0 |
HIP 28965 |
14.00 |
| 2026-03-27 12:00 |
06:07:24.22 |
+20:32:09.6 |
HIP 28965 |
14.99 |
| 2026-03-28 00:00 |
06:07:34.67 |
+20:32:37.1 |
HIP 28965 |
16.32 |
| 2026-03-28 12:00 |
06:07:45.27 |
+20:33:04.3 |
HIP 29010 |
17.36 |
| 2026-03-29 00:00 |
06:07:56.03 |
+20:33:31.4 |
HIP 29010 |
18.04 |
| 2026-03-29 12:00 |
06:08:06.94 |
+20:33:58.4 |
HIP 29010 |
19.07 |
| 2026-03-30 00:00 |
06:08:18.01 |
+20:34:25.1 |
HIP 29216 |
19.78 |
| 2026-03-30 12:00 |
06:08:29.22 |
+20:34:51.7 |
HIP 29216 |
17.40 |
| 2026-03-31 00:00 |
06:08:40.59 |
+20:35:18.1 |
HIP 29216 |
15.07 |
| 2026-03-31 12:00 |
06:08:52.11 |
+20:35:44.4 |
HIP 29216 |
12.86 |
| 2026-04-01 00:00 |
06:09:03.78 |
+20:36:10.4 |
HIP 29216 |
10.86 |
| 2026-04-01 12:00 |
06:09:15.60 |
+20:36:36.3 |
HIP 29216 |
9.24 |
| 2026-04-02 00:00 |
06:09:27.57 |
+20:37:02.0 |
HIP 29216 |
8.27 |
| 2026-04-02 12:00 |
06:09:39.69 |
+20:37:27.5 |
HIP 29216 |
8.20 |
| 2026-04-03 00:00 |
06:09:51.95 |
+20:37:52.8 |
HIP 29216 |
9.10 |
| 2026-04-03 12:00 |
06:10:04.35 |
+20:38:17.9 |
HIP 29216 |
10.74 |
| 2026-04-04 00:00 |
06:10:16.90 |
+20:38:42.9 |
HIP 29216 |
12.88 |
| 2026-04-04 12:00 |
06:10:29.60 |
+20:39:07.6 |
HIP 29354 |
11.85 |
| 2026-04-05 00:00 |
06:10:42.44 |
+20:39:32.1 |
HIP 29354 |
9.48 |
| 2026-04-05 12:00 |
06:10:55.42 |
+20:39:56.5 |
HIP 29354 |
7.57 |
| 2026-04-06 00:00 |
06:11:08.54 |
+20:40:20.6 |
HIP 29354 |
6.59 |
| 2026-04-06 12:00 |
06:11:21.80 |
+20:40:44.6 |
HIP 29354 |
6.97 |
| 2026-04-07 00:00 |
06:11:35.20 |
+20:41:08.3 |
HIP 29354 |
8.59 |
| 2026-04-07 12:00 |
06:11:48.75 |
+20:41:31.8 |
HIP 29354 |
10.92 |
| 2026-04-08 00:00 |
06:12:02.43 |
+20:41:55.2 |
HIP 29354 |
13.64 |
| 2026-04-08 12:00 |
06:12:16.24 |
+20:42:18.3 |
HIP 29354 |
16.56 |
| 2026-04-09 00:00 |
06:12:30.20 |
+20:42:41.2 |
HIP 29367 |
19.51 |
| 2026-04-09 12:00 |
06:12:44.29 |
+20:43:03.9 |
HIP 29367 |
22.05 |
| 2026-04-10 00:00 |
06:12:58.51 |
+20:43:26.3 |
HIP 29367 |
24.80 |
| 2026-04-10 12:00 |
06:13:12.87 |
+20:43:48.6 |
HIP 29367 |
27.71 |
| 2026-04-11 00:00 |
06:13:27.37 |
+20:44:10.6 |
HIP 29367 |
30.74 |
| 2026-04-11 12:00 |
06:13:41.99 |
+20:44:32.4 |
HIP 29492 |
33.10 |
| 2026-04-12 00:00 |
06:13:56.75 |
+20:44:54.0 |
HIP 29492 |
34.11 |
| 2026-04-12 12:00 |
06:14:11.64 |
+20:45:15.3 |
HIP 29744 |
31.55 |
| 2026-04-13 00:00 |
06:14:26.66 |
+20:45:36.4 |
HIP 29744 |
28.76 |
| 2026-04-13 12:00 |
06:14:41.81 |
+20:45:57.3 |
HIP 29744 |
26.13 |
| 2026-04-14 00:00 |
06:14:57.09 |
+20:46:17.9 |
HIP 29744 |
23.73 |
| 2026-04-14 12:00 |
06:15:12.49 |
+20:46:38.3 |
HIP 29744 |
21.66 |
| 2026-04-15 00:00 |
06:15:28.03 |
+20:46:58.5 |
HIP 29744 |
20.02 |
| 2026-04-15 12:00 |
06:15:43.69 |
+20:47:18.4 |
HIP 29744 |
18.94 |
| 2026-04-16 00:00 |
06:15:59.47 |
+20:47:38.1 |
HIP 29744 |
18.55 |