| Parameter |
Value |
| Designation |
C/2008 Q3 (Garradd) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2009-06-23T02:14:05.628480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:22Z |
| Obs used |
701 |
| NEO |
- |
| M1 |
6.300 |
| K1 |
16.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2009-08-27.0000000 |
| e |
0.99979780 |
| q (au) |
1.798229 |
| a (au) |
8893.448410 |
| i (deg) |
140.706611 |
| Ω (om, deg) |
219.734004 |
| ω (w, deg) |
340.855249 |
| M (ma, deg) |
0.000076 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.290 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.290 |
| 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 |
| 2008-08-27 |
2009-06-22 |
+8.4849 |
-4.214 |
| 2009-06-23 |
2009-12-15 |
+8.2759 |
-4.371 |
| 2009-12-15 |
2010-06-03 |
-2.7074 |
+1.180 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
04:50:57.39 |
+48:40:05.1 |
HIP 22545 |
4.79 |
| 2026-06-01 12:00 |
04:51:02.02 |
+48:40:07.2 |
HIP 22545 |
4.49 |
| 2026-06-02 00:00 |
04:51:06.64 |
+48:40:09.5 |
HIP 22545 |
4.31 |
| 2026-06-02 12:00 |
04:51:11.27 |
+48:40:11.9 |
HIP 22545 |
4.26 |
| 2026-06-03 00:00 |
04:51:15.90 |
+48:40:14.5 |
HIP 22545 |
4.34 |
| 2026-06-03 12:00 |
04:51:20.53 |
+48:40:17.2 |
HIP 22545 |
4.55 |
| 2026-06-04 00:00 |
04:51:25.15 |
+48:40:20.2 |
HIP 22545 |
4.87 |
| 2026-06-04 12:00 |
04:51:29.78 |
+48:40:23.3 |
HIP 22545 |
5.27 |
| 2026-06-05 00:00 |
04:51:34.42 |
+48:40:26.5 |
HIP 22545 |
5.75 |
| 2026-06-05 12:00 |
04:51:39.05 |
+48:40:30.0 |
HIP 22545 |
6.29 |
| 2026-06-06 00:00 |
04:51:43.68 |
+48:40:33.6 |
HIP 22545 |
6.87 |
| 2026-06-06 12:00 |
04:51:48.30 |
+48:40:37.4 |
HIP 22545 |
7.48 |
| 2026-06-07 00:00 |
04:51:52.93 |
+48:40:41.3 |
HIP 22545 |
8.11 |
| 2026-06-07 12:00 |
04:51:57.56 |
+48:40:45.4 |
HIP 22545 |
8.76 |
| 2026-06-08 00:00 |
04:52:02.18 |
+48:40:49.7 |
HIP 22545 |
9.43 |
| 2026-06-08 12:00 |
04:52:06.81 |
+48:40:54.1 |
HIP 22545 |
10.12 |
| 2026-06-09 00:00 |
04:52:11.43 |
+48:40:58.7 |
HIP 22545 |
10.81 |
| 2026-06-09 12:00 |
04:52:16.05 |
+48:41:03.5 |
HIP 22545 |
11.51 |
| 2026-06-10 00:00 |
04:52:20.66 |
+48:41:08.4 |
HIP 22545 |
12.22 |
| 2026-06-10 12:00 |
04:52:25.27 |
+48:41:13.5 |
HIP 22545 |
12.93 |
| 2026-06-11 00:00 |
04:52:29.88 |
+48:41:18.8 |
HIP 22545 |
13.65 |
| 2026-06-11 12:00 |
04:52:34.49 |
+48:41:24.2 |
HIP 22545 |
14.37 |
| 2026-06-12 00:00 |
04:52:39.09 |
+48:41:29.8 |
HIP 22545 |
15.09 |
| 2026-06-12 12:00 |
04:52:43.69 |
+48:41:35.6 |
HIP 22545 |
15.82 |
| 2026-06-13 00:00 |
04:52:48.28 |
+48:41:41.5 |
HIP 22545 |
16.55 |
| 2026-06-13 12:00 |
04:52:52.87 |
+48:41:47.6 |
HIP 22545 |
17.28 |
| 2026-06-14 00:00 |
04:52:57.45 |
+48:41:53.8 |
HIP 22545 |
18.01 |
| 2026-06-14 12:00 |
04:53:02.02 |
+48:42:00.3 |
HIP 22545 |
18.74 |
| 2026-06-15 00:00 |
04:53:06.59 |
+48:42:06.8 |
HIP 22545 |
19.47 |
| 2026-06-15 12:00 |
04:53:11.16 |
+48:42:13.5 |
HIP 22545 |
20.21 |
| 2026-06-16 00:00 |
04:53:15.71 |
+48:42:20.4 |
HIP 22545 |
20.94 |
| 2026-06-16 12:00 |
04:53:20.26 |
+48:42:27.5 |
HIP 22545 |
21.68 |
| 2026-06-17 00:00 |
04:53:24.80 |
+48:42:34.7 |
HIP 22545 |
22.41 |
| 2026-06-17 12:00 |
04:53:29.34 |
+48:42:42.0 |
HIP 22545 |
23.15 |
| 2026-06-18 00:00 |
04:53:33.87 |
+48:42:49.6 |
HIP 22841 |
23.33 |
| 2026-06-18 12:00 |
04:53:38.38 |
+48:42:57.2 |
HIP 22841 |
22.82 |
| 2026-06-19 00:00 |
04:53:42.89 |
+48:43:05.1 |
HIP 22841 |
22.33 |
| 2026-06-19 12:00 |
04:53:47.39 |
+48:43:13.1 |
HIP 22841 |
21.85 |
| 2026-06-20 00:00 |
04:53:51.88 |
+48:43:21.2 |
HIP 22841 |
21.38 |
| 2026-06-20 12:00 |
04:53:56.37 |
+48:43:29.5 |
HIP 22841 |
20.93 |
| 2026-06-21 00:00 |
04:54:00.84 |
+48:43:38.0 |
HIP 22841 |
20.50 |
| 2026-06-21 12:00 |
04:54:05.30 |
+48:43:46.6 |
HIP 22841 |
20.08 |
| 2026-06-22 00:00 |
04:54:09.75 |
+48:43:55.3 |
HIP 22841 |
19.68 |