| 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) |
| 2026-03-26 00:00 |
01:17:18.84 |
+52:19:25.4 |
HIP 6035 |
2.27 |
| 2026-03-26 12:00 |
01:17:23.59 |
+52:19:33.0 |
HIP 6035 |
1.62 |
| 2026-03-27 00:00 |
01:17:28.36 |
+52:19:41.0 |
HIP 6035 |
1.08 |
| 2026-03-27 12:00 |
01:17:33.13 |
+52:19:49.3 |
HIP 6035 |
0.89 |
| 2026-03-28 00:00 |
01:17:37.91 |
+52:19:57.8 |
HIP 6035 |
1.23 |
| 2026-03-28 12:00 |
01:17:42.70 |
+52:20:06.7 |
HIP 6035 |
1.82 |
| 2026-03-29 00:00 |
01:17:47.50 |
+52:20:15.9 |
HIP 6035 |
2.50 |
| 2026-03-29 12:00 |
01:17:52.31 |
+52:20:25.5 |
HIP 6035 |
3.22 |
| 2026-03-30 00:00 |
01:17:57.13 |
+52:20:35.3 |
HIP 6035 |
3.94 |
| 2026-03-30 12:00 |
01:18:01.95 |
+52:20:45.4 |
HIP 6035 |
4.68 |
| 2026-03-31 00:00 |
01:18:06.79 |
+52:20:55.9 |
HIP 6035 |
5.43 |
| 2026-03-31 12:00 |
01:18:11.63 |
+52:21:06.7 |
HIP 6035 |
6.17 |
| 2026-04-01 00:00 |
01:18:16.48 |
+52:21:17.8 |
HIP 6035 |
6.93 |
| 2026-04-01 12:00 |
01:18:21.34 |
+52:21:29.1 |
HIP 6035 |
7.68 |
| 2026-04-02 00:00 |
01:18:26.20 |
+52:21:40.8 |
HIP 6035 |
8.44 |
| 2026-04-02 12:00 |
01:18:31.07 |
+52:21:52.9 |
HIP 6035 |
9.21 |
| 2026-04-03 00:00 |
01:18:35.95 |
+52:22:05.2 |
HIP 6035 |
9.97 |
| 2026-04-03 12:00 |
01:18:40.83 |
+52:22:17.8 |
HIP 6035 |
10.74 |
| 2026-04-04 00:00 |
01:18:45.72 |
+52:22:30.7 |
HIP 6035 |
11.51 |
| 2026-04-04 12:00 |
01:18:50.61 |
+52:22:43.9 |
HIP 6035 |
12.28 |
| 2026-04-05 00:00 |
01:18:55.51 |
+52:22:57.5 |
HIP 6035 |
13.06 |
| 2026-04-05 12:00 |
01:19:00.41 |
+52:23:11.3 |
HIP 6035 |
13.84 |
| 2026-04-06 00:00 |
01:19:05.32 |
+52:23:25.4 |
HIP 6035 |
14.61 |
| 2026-04-06 12:00 |
01:19:10.23 |
+52:23:39.9 |
HIP 6035 |
15.40 |
| 2026-04-07 00:00 |
01:19:15.15 |
+52:23:54.6 |
HIP 6035 |
16.18 |
| 2026-04-07 12:00 |
01:19:20.06 |
+52:24:09.6 |
HIP 6035 |
16.96 |
| 2026-04-08 00:00 |
01:19:24.98 |
+52:24:25.0 |
HIP 6238 |
16.60 |
| 2026-04-08 12:00 |
01:19:29.91 |
+52:24:40.6 |
HIP 6238 |
16.11 |
| 2026-04-09 00:00 |
01:19:34.83 |
+52:24:56.5 |
HIP 6238 |
15.63 |
| 2026-04-09 12:00 |
01:19:39.76 |
+52:25:12.8 |
HIP 6238 |
15.18 |
| 2026-04-10 00:00 |
01:19:44.69 |
+52:25:29.3 |
HIP 6238 |
14.75 |
| 2026-04-10 12:00 |
01:19:49.62 |
+52:25:46.1 |
HIP 6238 |
14.35 |
| 2026-04-11 00:00 |
01:19:54.55 |
+52:26:03.2 |
HIP 6238 |
13.98 |
| 2026-04-11 12:00 |
01:19:59.49 |
+52:26:20.6 |
HIP 6238 |
13.64 |
| 2026-04-12 00:00 |
01:20:04.42 |
+52:26:38.3 |
HIP 6238 |
13.33 |
| 2026-04-12 12:00 |
01:20:09.35 |
+52:26:56.3 |
HIP 6238 |
13.07 |
| 2026-04-13 00:00 |
01:20:14.29 |
+52:27:14.6 |
HIP 6238 |
12.84 |
| 2026-04-13 12:00 |
01:20:19.22 |
+52:27:33.1 |
HIP 6238 |
12.66 |
| 2026-04-14 00:00 |
01:20:24.15 |
+52:27:52.0 |
HIP 6238 |
12.52 |
| 2026-04-14 12:00 |
01:20:29.08 |
+52:28:11.1 |
HIP 6238 |
12.43 |
| 2026-04-15 00:00 |
01:20:34.01 |
+52:28:30.5 |
HIP 6238 |
12.38 |
| 2026-04-15 12:00 |
01:20:38.93 |
+52:28:50.2 |
HIP 6238 |
12.39 |
| 2026-04-16 00:00 |
01:20:43.86 |
+52:29:10.2 |
HIP 6238 |
12.44 |