| Parameter |
Value |
| Designation |
186P/Garradd |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2008-05-28T23:37:34.250880Z |
| Orbit solution date (soln_date, UTC) |
2022-12-08T23:43:24Z |
| Obs used |
880 |
| NEO |
- |
| M1 |
6.500 |
| K1 |
12.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-08-03.0000000 |
| e |
0.12684331 |
| q (au) |
4.321945 |
| a (au) |
4.949793 |
| i (deg) |
28.544006 |
| Ω (om, deg) |
327.580045 |
| ω (w, deg) |
287.339155 |
| M (ma, deg) |
103.910997 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.628 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.628 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.829 |
| k |
0.800 |
| 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 |
| 2016-05-02 |
2022-11-04 |
+52.8866 |
-34.022 |
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 |
07:13:35.19 |
+36:48:25.4 |
HIP 35137 |
27.11 |
| 2026-05-12 12:00 |
07:13:58.78 |
+36:45:53.5 |
HIP 35137 |
22.39 |
| 2026-05-13 00:00 |
07:14:22.48 |
+36:43:21.7 |
HIP 35137 |
18.02 |
| 2026-05-13 12:00 |
07:14:46.29 |
+36:40:50.0 |
HIP 35137 |
14.32 |
| 2026-05-14 00:00 |
07:15:10.20 |
+36:38:18.4 |
HIP 35137 |
11.97 |
| 2026-05-14 12:00 |
07:15:34.21 |
+36:35:47.0 |
HIP 35137 |
11.82 |
| 2026-05-15 00:00 |
07:15:58.33 |
+36:33:15.6 |
HIP 35137 |
13.98 |
| 2026-05-15 12:00 |
07:16:22.54 |
+36:30:44.4 |
HIP 35137 |
17.63 |
| 2026-05-16 00:00 |
07:16:46.86 |
+36:28:13.3 |
HIP 35137 |
22.05 |
| 2026-05-16 12:00 |
07:17:11.27 |
+36:25:42.2 |
HIP 35282 |
25.93 |
| 2026-05-17 00:00 |
07:17:35.78 |
+36:23:11.3 |
HIP 35282 |
23.57 |
| 2026-05-17 12:00 |
07:18:00.38 |
+36:20:40.5 |
HIP 35282 |
22.38 |
| 2026-05-18 00:00 |
07:18:25.08 |
+36:18:09.8 |
HIP 35282 |
22.56 |
| 2026-05-18 12:00 |
07:18:49.87 |
+36:15:39.2 |
HIP 35282 |
24.08 |
| 2026-05-19 00:00 |
07:19:14.75 |
+36:13:08.7 |
HIP 35282 |
26.74 |
| 2026-05-19 12:00 |
07:19:39.73 |
+36:10:38.3 |
HIP 35688 |
27.05 |
| 2026-05-20 00:00 |
07:20:04.79 |
+36:08:08.0 |
HIP 35688 |
21.59 |
| 2026-05-20 12:00 |
07:20:29.94 |
+36:05:37.8 |
HIP 35688 |
16.23 |
| 2026-05-21 00:00 |
07:20:55.18 |
+36:03:07.7 |
HIP 35688 |
11.15 |
| 2026-05-21 12:00 |
07:21:20.51 |
+36:00:37.7 |
HIP 35688 |
7.04 |
| 2026-05-22 00:00 |
07:21:45.92 |
+35:58:07.7 |
HIP 35688 |
6.28 |
| 2026-05-22 12:00 |
07:22:11.41 |
+35:55:37.9 |
HIP 35755 |
4.30 |
| 2026-05-23 00:00 |
07:22:36.98 |
+35:53:08.1 |
HIP 35755 |
1.47 |
| 2026-05-23 12:00 |
07:23:02.64 |
+35:50:38.4 |
HIP 35755 |
7.22 |
| 2026-05-24 00:00 |
07:23:28.38 |
+35:48:08.8 |
HIP 35755 |
13.00 |
| 2026-05-24 12:00 |
07:23:54.19 |
+35:45:39.3 |
HIP 35880 |
16.02 |
| 2026-05-25 00:00 |
07:24:20.09 |
+35:43:09.9 |
HIP 35880 |
14.70 |
| 2026-05-25 12:00 |
07:24:46.06 |
+35:40:40.5 |
HIP 35880 |
15.61 |
| 2026-05-26 00:00 |
07:25:12.10 |
+35:38:11.3 |
HIP 35880 |
18.44 |
| 2026-05-26 12:00 |
07:25:38.22 |
+35:35:42.1 |
HIP 36044 |
16.39 |
| 2026-05-27 00:00 |
07:26:04.42 |
+35:33:12.9 |
HIP 36183 |
12.92 |
| 2026-05-27 12:00 |
07:26:30.69 |
+35:30:43.8 |
HIP 36183 |
7.23 |
| 2026-05-28 00:00 |
07:26:57.03 |
+35:28:14.8 |
HIP 36183 |
2.67 |
| 2026-05-28 12:00 |
07:27:23.44 |
+35:25:45.9 |
HIP 36183 |
5.64 |
| 2026-05-29 00:00 |
07:27:49.92 |
+35:23:17.0 |
HIP 36183 |
11.27 |
| 2026-05-29 12:00 |
07:28:16.47 |
+35:20:48.2 |
HIP 36183 |
17.12 |
| 2026-05-30 00:00 |
07:28:43.08 |
+35:18:19.4 |
HIP 36412 |
12.94 |
| 2026-05-30 12:00 |
07:29:09.77 |
+35:15:50.7 |
HIP 36412 |
7.40 |
| 2026-05-31 00:00 |
07:29:36.52 |
+35:13:22.1 |
HIP 36412 |
3.71 |
| 2026-05-31 12:00 |
07:30:03.34 |
+35:10:53.5 |
HIP 36412 |
6.71 |
| 2026-06-01 00:00 |
07:30:30.22 |
+35:08:24.9 |
HIP 36412 |
12.21 |
| 2026-06-01 12:00 |
07:30:57.17 |
+35:05:56.4 |
HIP 36412 |
18.06 |
| 2026-06-02 00:00 |
07:31:24.18 |
+35:03:28.0 |
HIP 36412 |
24.02 |