| 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) |
| 2026-07-29 00:00 |
04:58:50.71 |
+49:00:52.3 |
HIP 23198 |
15.62 |
| 2026-07-29 12:00 |
04:58:53.59 |
+49:01:10.2 |
HIP 23198 |
15.70 |
| 2026-07-30 00:00 |
04:58:56.45 |
+49:01:28.2 |
HIP 23198 |
15.79 |
| 2026-07-30 12:00 |
04:58:59.27 |
+49:01:46.3 |
HIP 23198 |
15.91 |
| 2026-07-31 00:00 |
04:59:02.07 |
+49:02:04.4 |
HIP 23198 |
16.05 |
| 2026-07-31 12:00 |
04:59:04.83 |
+49:02:22.7 |
HIP 23198 |
16.21 |
| 2026-08-01 00:00 |
04:59:07.56 |
+49:02:41.0 |
HIP 23198 |
16.39 |
| 2026-08-01 12:00 |
04:59:10.26 |
+49:02:59.4 |
HIP 23198 |
16.58 |
| 2026-08-02 00:00 |
04:59:12.93 |
+49:03:17.9 |
HIP 23198 |
16.80 |
| 2026-08-02 12:00 |
04:59:15.56 |
+49:03:36.5 |
HIP 23198 |
17.03 |
| 2026-08-03 00:00 |
04:59:18.17 |
+49:03:55.1 |
HIP 23198 |
17.28 |
| 2026-08-03 12:00 |
04:59:20.74 |
+49:04:13.8 |
HIP 23198 |
17.54 |
| 2026-08-04 00:00 |
04:59:23.28 |
+49:04:32.6 |
HIP 23198 |
17.81 |
| 2026-08-04 12:00 |
04:59:25.79 |
+49:04:51.5 |
HIP 23198 |
18.09 |
| 2026-08-05 00:00 |
04:59:28.26 |
+49:05:10.5 |
HIP 23198 |
18.39 |
| 2026-08-05 12:00 |
04:59:30.70 |
+49:05:29.5 |
HIP 23198 |
18.70 |
| 2026-08-06 00:00 |
04:59:33.10 |
+49:05:48.6 |
HIP 23198 |
19.02 |
| 2026-08-06 12:00 |
04:59:35.48 |
+49:06:07.7 |
HIP 23198 |
19.35 |
| 2026-08-07 00:00 |
04:59:37.82 |
+49:06:26.9 |
HIP 23198 |
19.68 |
| 2026-08-07 12:00 |
04:59:40.12 |
+49:06:46.2 |
HIP 23367 |
19.84 |
| 2026-08-08 00:00 |
04:59:42.39 |
+49:07:05.6 |
HIP 23367 |
19.67 |
| 2026-08-08 12:00 |
04:59:44.63 |
+49:07:25.0 |
HIP 23367 |
19.51 |
| 2026-08-09 00:00 |
04:59:46.83 |
+49:07:44.5 |
HIP 23367 |
19.37 |
| 2026-08-09 12:00 |
04:59:48.99 |
+49:08:04.0 |
HIP 23367 |
19.25 |
| 2026-08-10 00:00 |
04:59:51.12 |
+49:08:23.7 |
HIP 23367 |
19.14 |
| 2026-08-10 12:00 |
04:59:53.22 |
+49:08:43.3 |
HIP 23367 |
19.05 |
| 2026-08-11 00:00 |
04:59:55.27 |
+49:09:03.0 |
HIP 23367 |
18.98 |
| 2026-08-11 12:00 |
04:59:57.30 |
+49:09:22.8 |
HIP 23367 |
18.93 |
| 2026-08-12 00:00 |
04:59:59.28 |
+49:09:42.7 |
HIP 23367 |
18.89 |
| 2026-08-12 12:00 |
05:00:01.23 |
+49:10:02.6 |
HIP 23367 |
18.86 |
| 2026-08-13 00:00 |
05:00:03.15 |
+49:10:22.5 |
HIP 23367 |
18.86 |
| 2026-08-13 12:00 |
05:00:05.02 |
+49:10:42.5 |
HIP 23367 |
18.87 |
| 2026-08-14 00:00 |
05:00:06.86 |
+49:11:02.5 |
HIP 23367 |
18.89 |
| 2026-08-14 12:00 |
05:00:08.66 |
+49:11:22.6 |
HIP 23367 |
18.93 |
| 2026-08-15 00:00 |
05:00:10.43 |
+49:11:42.8 |
HIP 23367 |
18.99 |
| 2026-08-15 12:00 |
05:00:12.15 |
+49:12:02.9 |
HIP 23367 |
19.06 |
| 2026-08-16 00:00 |
05:00:13.84 |
+49:12:23.2 |
HIP 23367 |
19.14 |
| 2026-08-16 12:00 |
05:00:15.50 |
+49:12:43.4 |
HIP 23367 |
19.24 |
| 2026-08-17 00:00 |
05:00:17.11 |
+49:13:03.7 |
HIP 23367 |
19.36 |
| 2026-08-17 12:00 |
05:00:18.68 |
+49:13:24.1 |
HIP 23367 |
19.48 |
| 2026-08-18 00:00 |
05:00:20.22 |
+49:13:44.5 |
HIP 23367 |
19.62 |
| 2026-08-18 12:00 |
05:00:21.72 |
+49:14:04.9 |
HIP 23367 |
19.77 |
| 2026-08-19 00:00 |
05:00:23.18 |
+49:14:25.3 |
HIP 23367 |
19.93 |