146P/Shoemaker-LINEAR
| Parameter |
Value |
| Designation |
146P/Shoemaker-LINEAR |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2024-08-05T08:53:48.851520Z |
| Orbit solution date (soln_date, UTC) |
2025-05-09T00:50:37Z |
| Obs used |
660 |
| NEO |
- |
| M1 |
12.200 |
| K1 |
21.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2022-04-07.0000000 |
| e |
0.64733427 |
| q (au) |
1.421549 |
| a (au) |
4.030867 |
| i (deg) |
23.109042 |
| Ω (om, deg) |
53.379790 |
| ω (w, deg) |
316.990390 |
| M (ma, deg) |
256.312817 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.467 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.467 |
| n |
6.000 |
| gf |
1.000 |
| 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 |
| 2024-05-06 |
2024-08-05 |
+10.3090 |
-2.699 |
| 2024-08-06 |
2024-10-12 |
+42.9787 |
-7.408 |
| 2024-10-12 |
2025-05-01 |
-11.2690 |
+3.718 |
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 |
11:18:34.77 |
+35:40:58.6 |
HIP 55243 |
11.94 |
| 2026-02-03 12:00 |
11:18:14.97 |
+35:44:03.7 |
HIP 55251 |
13.06 |
| 2026-02-04 00:00 |
11:17:54.96 |
+35:47:07.7 |
HIP 55251 |
14.31 |
| 2026-02-04 12:00 |
11:17:34.75 |
+35:50:10.5 |
HIP 55251 |
17.10 |
| 2026-02-05 00:00 |
11:17:14.34 |
+35:53:12.1 |
HIP 54996 |
19.88 |
| 2026-02-05 12:00 |
11:16:53.73 |
+35:56:12.3 |
HIP 54996 |
16.48 |
| 2026-02-06 00:00 |
11:16:32.93 |
+35:59:11.3 |
HIP 54996 |
14.13 |
| 2026-02-06 12:00 |
11:16:11.95 |
+36:02:09.0 |
HIP 54996 |
13.42 |
| 2026-02-07 00:00 |
11:15:50.78 |
+36:05:05.3 |
HIP 54996 |
14.61 |
| 2026-02-07 12:00 |
11:15:29.42 |
+36:08:00.2 |
HIP 55009 |
15.31 |
| 2026-02-08 00:00 |
11:15:07.89 |
+36:10:53.6 |
HIP 55009 |
14.33 |
| 2026-02-08 12:00 |
11:14:46.18 |
+36:13:45.6 |
HIP 55009 |
15.23 |
| 2026-02-09 00:00 |
11:14:24.30 |
+36:16:36.0 |
HIP 55009 |
17.74 |
| 2026-02-09 12:00 |
11:14:02.25 |
+36:19:25.0 |
HIP 55009 |
21.30 |
| 2026-02-10 00:00 |
11:13:40.04 |
+36:22:12.3 |
HIP 55009 |
25.48 |
| 2026-02-10 12:00 |
11:13:17.66 |
+36:24:58.0 |
HIP 55009 |
30.04 |
| 2026-02-11 00:00 |
11:12:55.13 |
+36:27:42.1 |
HIP 54726 |
27.09 |
| 2026-02-11 12:00 |
11:12:32.45 |
+36:30:24.5 |
HIP 54726 |
23.42 |
| 2026-02-12 00:00 |
11:12:09.62 |
+36:33:05.2 |
HIP 54726 |
20.50 |
| 2026-02-12 12:00 |
11:11:46.64 |
+36:35:44.2 |
HIP 54726 |
18.70 |
| 2026-02-13 00:00 |
11:11:23.52 |
+36:38:21.4 |
HIP 54726 |
18.35 |
| 2026-02-13 12:00 |
11:11:00.26 |
+36:40:56.8 |
HIP 54726 |
19.55 |
| 2026-02-14 00:00 |
11:10:36.87 |
+36:43:30.3 |
HIP 54726 |
22.04 |
| 2026-02-14 12:00 |
11:10:13.35 |
+36:46:02.0 |
HIP 54422 |
24.28 |
| 2026-02-15 00:00 |
11:09:49.71 |
+36:48:31.7 |
HIP 54422 |
19.71 |
| 2026-02-15 12:00 |
11:09:25.95 |
+36:50:59.6 |
HIP 54422 |
15.62 |
| 2026-02-16 00:00 |
11:09:02.07 |
+36:53:25.4 |
HIP 54422 |
12.50 |
| 2026-02-16 12:00 |
11:08:38.08 |
+36:55:49.3 |
HIP 54422 |
11.19 |
| 2026-02-17 00:00 |
11:08:13.99 |
+36:58:11.2 |
HIP 54422 |
12.28 |
| 2026-02-17 12:00 |
11:07:49.79 |
+37:00:31.0 |
HIP 54422 |
15.27 |
| 2026-02-18 00:00 |
11:07:25.49 |
+37:02:48.8 |
HIP 54343 |
19.22 |
| 2026-02-18 12:00 |
11:07:01.11 |
+37:05:04.4 |
HIP 54343 |
20.88 |
| 2026-02-19 00:00 |
11:06:36.63 |
+37:07:18.0 |
HIP 54343 |
23.64 |
| 2026-02-19 12:00 |
11:06:12.07 |
+37:09:29.3 |
HIP 54343 |
27.16 |
| 2026-02-20 00:00 |
11:05:47.44 |
+37:11:38.5 |
HIP 54343 |
31.19 |
| 2026-02-20 12:00 |
11:05:22.73 |
+37:13:45.5 |
HIP 54343 |
35.56 |
| 2026-02-21 00:00 |
11:04:57.95 |
+37:15:50.3 |
HIP 53931 |
37.81 |
| 2026-02-21 12:00 |
11:04:33.11 |
+37:17:52.9 |
HIP 53931 |
34.53 |
| 2026-02-22 00:00 |
11:04:08.20 |
+37:19:53.1 |
HIP 53931 |
31.79 |
| 2026-02-22 12:00 |
11:03:43.25 |
+37:21:51.1 |
HIP 53931 |
29.73 |
| 2026-02-23 00:00 |
11:03:18.24 |
+37:23:46.8 |
HIP 53931 |
28.51 |
| 2026-02-23 12:00 |
11:02:53.19 |
+37:25:40.2 |
HIP 53931 |
28.22 |
| 2026-02-24 00:00 |
11:02:28.10 |
+37:27:31.2 |
HIP 53931 |
28.89 |