| 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
$$
M_a = (9.041 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.041 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.942 |
| k |
0.803 |
| δ90 |
5.940 |
| 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) |
| 2026-07-29 00:00 |
01:29:32.19 |
+54:35:24.1 |
HIP 6932 |
14.01 |
| 2026-07-29 12:00 |
01:29:30.73 |
+54:36:01.0 |
HIP 6932 |
14.59 |
| 2026-07-30 00:00 |
01:29:29.23 |
+54:36:37.8 |
HIP 6932 |
15.18 |
| 2026-07-30 12:00 |
01:29:27.68 |
+54:37:14.4 |
HIP 6932 |
15.77 |
| 2026-07-31 00:00 |
01:29:26.09 |
+54:37:50.9 |
HIP 6932 |
16.36 |
| 2026-07-31 12:00 |
01:29:24.45 |
+54:38:27.1 |
HIP 6932 |
16.95 |
| 2026-08-01 00:00 |
01:29:22.76 |
+54:39:03.2 |
HIP 6932 |
17.54 |
| 2026-08-01 12:00 |
01:29:21.02 |
+54:39:39.1 |
HIP 6932 |
18.13 |
| 2026-08-02 00:00 |
01:29:19.25 |
+54:40:14.9 |
HIP 6932 |
18.72 |
| 2026-08-02 12:00 |
01:29:17.42 |
+54:40:50.4 |
HIP 6932 |
19.32 |
| 2026-08-03 00:00 |
01:29:15.55 |
+54:41:25.8 |
HIP 6932 |
19.91 |
| 2026-08-03 12:00 |
01:29:13.63 |
+54:42:01.0 |
HIP 6932 |
20.51 |
| 2026-08-04 00:00 |
01:29:11.67 |
+54:42:36.0 |
HIP 6932 |
21.11 |
| 2026-08-04 12:00 |
01:29:09.66 |
+54:43:10.8 |
HIP 6932 |
21.70 |
| 2026-08-05 00:00 |
01:29:07.60 |
+54:43:45.5 |
HIP 6932 |
22.30 |
| 2026-08-05 12:00 |
01:29:05.50 |
+54:44:19.9 |
HIP 6932 |
22.89 |
| 2026-08-06 00:00 |
01:29:03.36 |
+54:44:54.1 |
HIP 6932 |
23.49 |
| 2026-08-06 12:00 |
01:29:01.16 |
+54:45:28.2 |
HIP 6932 |
24.09 |
| 2026-08-07 00:00 |
01:28:58.93 |
+54:46:02.0 |
HIP 6932 |
24.68 |
| 2026-08-07 12:00 |
01:28:56.64 |
+54:46:35.6 |
HIP 6932 |
25.28 |
| 2026-08-08 00:00 |
01:28:54.31 |
+54:47:09.0 |
HIP 6932 |
25.88 |
| 2026-08-08 12:00 |
01:28:51.94 |
+54:47:42.2 |
HIP 6932 |
26.48 |
| 2026-08-09 00:00 |
01:28:49.52 |
+54:48:15.2 |
HIP 6932 |
27.07 |
| 2026-08-09 12:00 |
01:28:47.05 |
+54:48:48.0 |
HIP 6932 |
27.67 |
| 2026-08-10 00:00 |
01:28:44.54 |
+54:49:20.6 |
HIP 6904 |
27.43 |
| 2026-08-10 12:00 |
01:28:41.99 |
+54:49:52.9 |
HIP 6904 |
26.91 |
| 2026-08-11 00:00 |
01:28:39.38 |
+54:50:25.0 |
HIP 6904 |
26.40 |
| 2026-08-11 12:00 |
01:28:36.74 |
+54:50:56.9 |
HIP 6904 |
25.90 |
| 2026-08-12 00:00 |
01:28:34.05 |
+54:51:28.6 |
HIP 6904 |
25.41 |
| 2026-08-12 12:00 |
01:28:31.31 |
+54:52:00.0 |
HIP 6904 |
24.94 |
| 2026-08-13 00:00 |
01:28:28.53 |
+54:52:31.2 |
HIP 6904 |
24.48 |
| 2026-08-13 12:00 |
01:28:25.71 |
+54:53:02.2 |
HIP 6904 |
24.03 |
| 2026-08-14 00:00 |
01:28:22.84 |
+54:53:32.9 |
HIP 6904 |
23.60 |
| 2026-08-14 12:00 |
01:28:19.93 |
+54:54:03.4 |
HIP 6904 |
23.18 |
| 2026-08-15 00:00 |
01:28:16.97 |
+54:54:33.7 |
HIP 6904 |
22.78 |
| 2026-08-15 12:00 |
01:28:13.97 |
+54:55:03.7 |
HIP 6904 |
22.40 |
| 2026-08-16 00:00 |
01:28:10.93 |
+54:55:33.4 |
HIP 6904 |
22.04 |
| 2026-08-16 12:00 |
01:28:07.84 |
+54:56:02.9 |
HIP 6904 |
21.69 |
| 2026-08-17 00:00 |
01:28:04.71 |
+54:56:32.2 |
HIP 6904 |
21.37 |
| 2026-08-17 12:00 |
01:28:01.54 |
+54:57:01.2 |
HIP 6904 |
21.07 |
| 2026-08-18 00:00 |
01:27:58.32 |
+54:57:29.9 |
HIP 6904 |
20.79 |
| 2026-08-18 12:00 |
01:27:55.06 |
+54:57:58.4 |
HIP 6667 |
20.37 |
| 2026-08-19 00:00 |
01:27:51.76 |
+54:58:26.6 |
HIP 6667 |
19.92 |