| 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) |
| 2026-07-29 00:00 |
08:26:16.87 |
+30:22:21.2 |
HIP 41482 |
20.10 |
| 2026-07-29 12:00 |
08:26:46.03 |
+30:19:53.5 |
HIP 41482 |
16.97 |
| 2026-07-30 00:00 |
08:27:15.16 |
+30:17:25.9 |
HIP 41482 |
16.20 |
| 2026-07-30 12:00 |
08:27:44.28 |
+30:14:58.2 |
HIP 41482 |
18.12 |
| 2026-07-31 00:00 |
08:28:13.38 |
+30:12:30.6 |
HIP 41624 |
12.14 |
| 2026-07-31 12:00 |
08:28:42.45 |
+30:10:03.0 |
HIP 41624 |
6.40 |
| 2026-08-01 00:00 |
08:29:11.51 |
+30:07:35.5 |
HIP 41624 |
5.06 |
| 2026-08-01 12:00 |
08:29:40.54 |
+30:05:08.0 |
HIP 41624 |
10.06 |
| 2026-08-02 00:00 |
08:30:09.55 |
+30:02:40.5 |
HIP 41624 |
16.36 |
| 2026-08-02 12:00 |
08:30:38.53 |
+30:00:13.1 |
HIP 41624 |
22.90 |
| 2026-08-03 00:00 |
08:31:07.49 |
+29:57:45.7 |
HIP 41841 |
17.88 |
| 2026-08-03 12:00 |
08:31:36.43 |
+29:55:18.3 |
HIP 41841 |
13.06 |
| 2026-08-04 00:00 |
08:32:05.34 |
+29:52:51.0 |
HIP 41841 |
10.59 |
| 2026-08-04 12:00 |
08:32:34.22 |
+29:50:23.7 |
HIP 41841 |
12.03 |
| 2026-08-05 00:00 |
08:33:03.08 |
+29:47:56.5 |
HIP 41841 |
16.36 |
| 2026-08-05 12:00 |
08:33:31.91 |
+29:45:29.3 |
HIP 41841 |
21.93 |
| 2026-08-06 00:00 |
08:34:00.72 |
+29:43:02.2 |
HIP 41841 |
28.01 |
| 2026-08-06 12:00 |
08:34:29.50 |
+29:40:35.2 |
HIP 42182 |
28.59 |
| 2026-08-07 00:00 |
08:34:58.24 |
+29:38:08.2 |
HIP 42182 |
26.73 |
| 2026-08-07 12:00 |
08:35:26.96 |
+29:35:41.2 |
HIP 42182 |
26.47 |
| 2026-08-08 00:00 |
08:35:55.65 |
+29:33:14.3 |
HIP 42182 |
27.87 |
| 2026-08-08 12:00 |
08:36:24.31 |
+29:30:47.5 |
HIP 42371 |
26.32 |
| 2026-08-09 00:00 |
08:36:52.94 |
+29:28:20.7 |
HIP 42371 |
21.40 |
| 2026-08-09 12:00 |
08:37:21.53 |
+29:25:54.0 |
HIP 42371 |
17.67 |
| 2026-08-10 00:00 |
08:37:50.09 |
+29:23:27.4 |
HIP 42371 |
16.00 |
| 2026-08-10 12:00 |
08:38:18.62 |
+29:21:00.9 |
HIP 42371 |
16.99 |
| 2026-08-11 00:00 |
08:38:47.12 |
+29:18:34.4 |
HIP 42514 |
17.26 |
| 2026-08-11 12:00 |
08:39:15.58 |
+29:16:08.0 |
HIP 42514 |
11.01 |
| 2026-08-12 00:00 |
08:39:44.00 |
+29:13:41.7 |
HIP 42514 |
5.81 |
| 2026-08-12 12:00 |
08:40:12.39 |
+29:11:15.5 |
HIP 42514 |
5.90 |
| 2026-08-13 00:00 |
08:40:40.74 |
+29:08:49.3 |
HIP 42514 |
11.15 |
| 2026-08-13 12:00 |
08:41:09.06 |
+29:06:23.3 |
HIP 42514 |
17.38 |
| 2026-08-14 00:00 |
08:41:37.33 |
+29:03:57.3 |
HIP 42514 |
23.83 |
| 2026-08-14 12:00 |
08:42:05.57 |
+29:01:31.5 |
HIP 42699 |
21.81 |
| 2026-08-15 00:00 |
08:42:33.76 |
+28:59:05.7 |
HIP 42699 |
20.21 |
| 2026-08-15 12:00 |
08:43:01.92 |
+28:56:40.1 |
HIP 42699 |
20.72 |
| 2026-08-16 00:00 |
08:43:30.03 |
+28:54:14.5 |
HIP 42699 |
23.18 |
| 2026-08-16 12:00 |
08:43:58.11 |
+28:51:49.1 |
HIP 42699 |
27.08 |
| 2026-08-17 00:00 |
08:44:26.14 |
+28:49:23.8 |
HIP 42976 |
26.81 |
| 2026-08-17 12:00 |
08:44:54.12 |
+28:46:58.6 |
HIP 42976 |
21.84 |
| 2026-08-18 00:00 |
08:45:22.06 |
+28:44:33.5 |
HIP 43100 |
17.13 |
| 2026-08-18 12:00 |
08:45:49.96 |
+28:42:08.5 |
HIP 43100 |
11.60 |
| 2026-08-19 00:00 |
08:46:17.82 |
+28:39:43.7 |
HIP 43100 |
7.87 |