C/2009 U1 (Garradd)
| Parameter |
Value |
| Designation |
C/2009 U1 (Garradd) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-10-07T22:02:42.892800Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:36Z |
| Obs used |
10 |
| NEO |
- |
| M1 |
7.800 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2009-10-19.0000000 |
| e |
1.01500924 |
| q (au) |
5.382605 |
| a (au) |
-358.619493 |
| i (deg) |
91.236070 |
| Ω (om, deg) |
43.385462 |
| ω (w, deg) |
269.043011 |
| M (ma, deg) |
0.054580 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.039 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.039 |
| n |
6.000 |
| gf |
0.976 |
| gb |
-0.942 |
| k |
0.801 |
| δ90 |
5.609 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
01:11:10.91 |
+52:34:33.2 |
HIP 5420 |
17.51 |
| 2026-02-03 12:00 |
01:11:12.88 |
+52:34:09.0 |
HIP 5420 |
17.85 |
| 2026-02-04 00:00 |
01:11:14.88 |
+52:33:45.1 |
HIP 5420 |
18.20 |
| 2026-02-04 12:00 |
01:11:16.93 |
+52:33:21.5 |
HIP 5420 |
18.57 |
| 2026-02-05 00:00 |
01:11:19.01 |
+52:32:58.1 |
HIP 5420 |
18.94 |
| 2026-02-05 12:00 |
01:11:21.14 |
+52:32:34.9 |
HIP 5708 |
19.22 |
| 2026-02-06 00:00 |
01:11:23.31 |
+52:32:12.1 |
HIP 5708 |
18.96 |
| 2026-02-06 12:00 |
01:11:25.52 |
+52:31:49.5 |
HIP 5708 |
18.71 |
| 2026-02-07 00:00 |
01:11:27.77 |
+52:31:27.2 |
HIP 5708 |
18.46 |
| 2026-02-07 12:00 |
01:11:30.06 |
+52:31:05.2 |
HIP 5708 |
18.22 |
| 2026-02-08 00:00 |
01:11:32.38 |
+52:30:43.4 |
HIP 5708 |
17.98 |
| 2026-02-08 12:00 |
01:11:34.75 |
+52:30:21.9 |
HIP 5708 |
17.74 |
| 2026-02-09 00:00 |
01:11:37.16 |
+52:30:00.7 |
HIP 5708 |
17.51 |
| 2026-02-09 12:00 |
01:11:39.61 |
+52:29:39.8 |
HIP 5708 |
17.28 |
| 2026-02-10 00:00 |
01:11:42.09 |
+52:29:19.2 |
HIP 5708 |
17.05 |
| 2026-02-10 12:00 |
01:11:44.61 |
+52:28:58.8 |
HIP 5708 |
16.83 |
| 2026-02-11 00:00 |
01:11:47.18 |
+52:28:38.8 |
HIP 5708 |
16.62 |
| 2026-02-11 12:00 |
01:11:49.78 |
+52:28:19.0 |
HIP 5708 |
16.41 |
| 2026-02-12 00:00 |
01:11:52.41 |
+52:27:59.5 |
HIP 5708 |
16.21 |
| 2026-02-12 12:00 |
01:11:55.09 |
+52:27:40.3 |
HIP 5708 |
16.01 |
| 2026-02-13 00:00 |
01:11:57.80 |
+52:27:21.4 |
HIP 5708 |
15.83 |
| 2026-02-13 12:00 |
01:12:00.55 |
+52:27:02.8 |
HIP 5708 |
15.65 |
| 2026-02-14 00:00 |
01:12:03.34 |
+52:26:44.5 |
HIP 5708 |
15.47 |
| 2026-02-14 12:00 |
01:12:06.16 |
+52:26:26.5 |
HIP 5708 |
15.31 |
| 2026-02-15 00:00 |
01:12:09.02 |
+52:26:08.7 |
HIP 5708 |
15.15 |
| 2026-02-15 12:00 |
01:12:11.92 |
+52:25:51.3 |
HIP 5708 |
15.01 |
| 2026-02-16 00:00 |
01:12:14.85 |
+52:25:34.2 |
HIP 5708 |
14.87 |
| 2026-02-16 12:00 |
01:12:17.81 |
+52:25:17.4 |
HIP 5708 |
14.74 |
| 2026-02-17 00:00 |
01:12:20.82 |
+52:25:00.9 |
HIP 5708 |
14.63 |
| 2026-02-17 12:00 |
01:12:23.85 |
+52:24:44.7 |
HIP 5708 |
14.53 |
| 2026-02-18 00:00 |
01:12:26.93 |
+52:24:28.8 |
HIP 5708 |
14.43 |
| 2026-02-18 12:00 |
01:12:30.03 |
+52:24:13.2 |
HIP 5708 |
14.35 |
| 2026-02-19 00:00 |
01:12:33.17 |
+52:23:57.9 |
HIP 5708 |
14.29 |
| 2026-02-19 12:00 |
01:12:36.34 |
+52:23:43.0 |
HIP 5708 |
14.23 |
| 2026-02-20 00:00 |
01:12:39.55 |
+52:23:28.3 |
HIP 5708 |
14.19 |
| 2026-02-20 12:00 |
01:12:42.79 |
+52:23:14.0 |
HIP 5708 |
14.16 |
| 2026-02-21 00:00 |
01:12:46.06 |
+52:23:00.0 |
HIP 5708 |
14.15 |
| 2026-02-21 12:00 |
01:12:49.37 |
+52:22:46.2 |
HIP 5708 |
14.15 |
| 2026-02-22 00:00 |
01:12:52.71 |
+52:22:32.8 |
HIP 5708 |
14.17 |
| 2026-02-22 12:00 |
01:12:56.08 |
+52:22:19.7 |
HIP 5708 |
14.20 |
| 2026-02-23 00:00 |
01:12:59.48 |
+52:22:06.9 |
HIP 5708 |
14.25 |
| 2026-02-23 12:00 |
01:13:02.91 |
+52:21:54.5 |
HIP 5708 |
14.31 |
| 2026-02-24 00:00 |
01:13:06.37 |
+52:21:42.3 |
HIP 5708 |
14.39 |