| 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) |
| 2026-05-12 00:00 |
10:25:38.96 |
+34:58:57.1 |
HIP 50968 |
12.46 |
| 2026-05-12 12:00 |
10:25:41.60 |
+34:56:06.8 |
HIP 50968 |
13.61 |
| 2026-05-13 00:00 |
10:25:44.44 |
+34:53:15.9 |
HIP 50968 |
15.27 |
| 2026-05-13 12:00 |
10:25:47.50 |
+34:50:24.3 |
HIP 50968 |
17.31 |
| 2026-05-14 00:00 |
10:25:50.76 |
+34:47:32.1 |
HIP 50968 |
19.62 |
| 2026-05-14 12:00 |
10:25:54.24 |
+34:44:39.3 |
HIP 50968 |
22.11 |
| 2026-05-15 00:00 |
10:25:57.91 |
+34:41:45.9 |
HIP 50968 |
24.75 |
| 2026-05-15 12:00 |
10:26:01.80 |
+34:38:51.9 |
HIP 50968 |
27.49 |
| 2026-05-16 00:00 |
10:26:05.89 |
+34:35:57.4 |
HIP 50968 |
30.31 |
| 2026-05-16 12:00 |
10:26:10.18 |
+34:33:02.3 |
HIP 50951 |
31.63 |
| 2026-05-17 00:00 |
10:26:14.67 |
+34:30:06.7 |
HIP 50951 |
30.34 |
| 2026-05-17 12:00 |
10:26:19.37 |
+34:27:10.5 |
HIP 50951 |
29.34 |
| 2026-05-18 00:00 |
10:26:24.26 |
+34:24:13.9 |
HIP 50951 |
28.67 |
| 2026-05-18 12:00 |
10:26:29.35 |
+34:21:16.7 |
HIP 50951 |
28.37 |
| 2026-05-19 00:00 |
10:26:34.64 |
+34:18:19.0 |
HIP 50951 |
28.44 |
| 2026-05-19 12:00 |
10:26:40.13 |
+34:15:20.8 |
HIP 50951 |
28.91 |
| 2026-05-20 00:00 |
10:26:45.81 |
+34:12:22.2 |
HIP 51056 |
26.76 |
| 2026-05-20 12:00 |
10:26:51.68 |
+34:09:23.1 |
HIP 51056 |
24.61 |
| 2026-05-21 00:00 |
10:26:57.74 |
+34:06:23.6 |
HIP 51056 |
22.73 |
| 2026-05-21 12:00 |
10:27:03.99 |
+34:03:23.6 |
HIP 51056 |
21.20 |
| 2026-05-22 00:00 |
10:27:10.43 |
+34:00:23.2 |
HIP 51056 |
20.12 |
| 2026-05-22 12:00 |
10:27:17.06 |
+33:57:22.3 |
HIP 51056 |
19.57 |
| 2026-05-23 00:00 |
10:27:23.87 |
+33:54:21.1 |
HIP 51056 |
19.61 |
| 2026-05-23 12:00 |
10:27:30.86 |
+33:51:19.5 |
HIP 51056 |
20.25 |
| 2026-05-24 00:00 |
10:27:38.04 |
+33:48:17.5 |
HIP 51056 |
21.44 |
| 2026-05-24 12:00 |
10:27:45.40 |
+33:45:15.1 |
HIP 51056 |
23.11 |
| 2026-05-25 00:00 |
10:27:52.94 |
+33:42:12.3 |
HIP 51056 |
25.17 |
| 2026-05-25 12:00 |
10:28:00.66 |
+33:39:09.2 |
HIP 51056 |
27.54 |
| 2026-05-26 00:00 |
10:28:08.55 |
+33:36:05.7 |
HIP 51056 |
30.16 |
| 2026-05-26 12:00 |
10:28:16.62 |
+33:33:01.9 |
HIP 51205 |
31.86 |
| 2026-05-27 00:00 |
10:28:24.87 |
+33:29:57.8 |
HIP 51205 |
29.52 |
| 2026-05-27 12:00 |
10:28:33.28 |
+33:26:53.3 |
HIP 51205 |
27.45 |
| 2026-05-28 00:00 |
10:28:41.87 |
+33:23:48.5 |
HIP 51205 |
25.71 |
| 2026-05-28 12:00 |
10:28:50.63 |
+33:20:43.5 |
HIP 51337 |
23.04 |
| 2026-05-29 00:00 |
10:28:59.56 |
+33:17:38.1 |
HIP 51337 |
19.71 |
| 2026-05-29 12:00 |
10:29:08.65 |
+33:14:32.4 |
HIP 51337 |
16.50 |
| 2026-05-30 00:00 |
10:29:17.91 |
+33:11:26.4 |
HIP 51337 |
13.51 |
| 2026-05-30 12:00 |
10:29:27.33 |
+33:08:20.2 |
HIP 51337 |
10.94 |
| 2026-05-31 00:00 |
10:29:36.92 |
+33:05:13.7 |
HIP 51337 |
9.17 |
| 2026-05-31 12:00 |
10:29:46.67 |
+33:02:06.9 |
HIP 51337 |
8.75 |
| 2026-06-01 00:00 |
10:29:56.58 |
+32:58:59.9 |
HIP 51337 |
9.87 |
| 2026-06-01 12:00 |
10:30:06.65 |
+32:55:52.6 |
HIP 51471 |
8.94 |
| 2026-06-02 00:00 |
10:30:16.88 |
+32:52:45.1 |
HIP 51471 |
7.28 |