| Parameter |
Value |
| Designation |
C/2010 H1 (Garradd) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2010-06-18T21:49:15.484800Z |
| Orbit solution date (soln_date, UTC) |
2022-07-06T03:12:21Z |
| Obs used |
46 |
| NEO |
- |
| M1 |
9.500 |
| K1 |
17.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2010-05-03.0000000 |
| e |
0.99965781 |
| q (au) |
2.745494 |
| a (au) |
8023.335869 |
| i (deg) |
36.531182 |
| Ω (om, deg) |
347.383773 |
| ω (w, deg) |
233.823547 |
| M (ma, deg) |
359.999936 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.811 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.811 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.996 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
23:56:08.06 |
+13:12:47.6 |
HIP 118089 |
16.70 |
| 2026-09-20 12:00 |
23:56:04.78 |
+13:12:30.0 |
HIP 118089 |
17.50 |
| 2026-09-21 00:00 |
23:56:01.50 |
+13:12:12.3 |
HIP 117899 |
17.02 |
| 2026-09-21 12:00 |
23:55:58.22 |
+13:11:54.5 |
HIP 117899 |
16.24 |
| 2026-09-22 00:00 |
23:55:54.94 |
+13:11:36.5 |
HIP 117899 |
15.46 |
| 2026-09-22 12:00 |
23:55:51.66 |
+13:11:18.5 |
HIP 117899 |
14.70 |
| 2026-09-23 00:00 |
23:55:48.39 |
+13:11:00.4 |
HIP 117899 |
13.94 |
| 2026-09-23 12:00 |
23:55:45.11 |
+13:10:42.1 |
HIP 117899 |
13.20 |
| 2026-09-24 00:00 |
23:55:41.84 |
+13:10:23.8 |
HIP 117899 |
12.47 |
| 2026-09-24 12:00 |
23:55:38.56 |
+13:10:05.3 |
HIP 117899 |
11.76 |
| 2026-09-25 00:00 |
23:55:35.29 |
+13:09:46.7 |
HIP 117899 |
11.07 |
| 2026-09-25 12:00 |
23:55:32.02 |
+13:09:28.1 |
HIP 117899 |
10.41 |
| 2026-09-26 00:00 |
23:55:28.75 |
+13:09:09.3 |
HIP 117899 |
9.77 |
| 2026-09-26 12:00 |
23:55:25.49 |
+13:08:50.4 |
HIP 117899 |
9.18 |
| 2026-09-27 00:00 |
23:55:22.22 |
+13:08:31.5 |
HIP 117899 |
8.63 |
| 2026-09-27 12:00 |
23:55:18.96 |
+13:08:12.4 |
HIP 117899 |
8.13 |
| 2026-09-28 00:00 |
23:55:15.71 |
+13:07:53.3 |
HIP 117899 |
7.70 |
| 2026-09-28 12:00 |
23:55:12.45 |
+13:07:34.1 |
HIP 117899 |
7.34 |
| 2026-09-29 00:00 |
23:55:09.20 |
+13:07:14.7 |
HIP 117899 |
7.07 |
| 2026-09-29 12:00 |
23:55:05.96 |
+13:06:55.3 |
HIP 117899 |
6.90 |
| 2026-09-30 00:00 |
23:55:02.72 |
+13:06:35.8 |
HIP 117899 |
6.84 |
| 2026-09-30 12:00 |
23:54:59.48 |
+13:06:16.2 |
HIP 117899 |
6.88 |
| 2026-10-01 00:00 |
23:54:56.25 |
+13:05:56.6 |
HIP 117899 |
7.03 |
| 2026-10-01 12:00 |
23:54:53.02 |
+13:05:36.8 |
HIP 117899 |
7.27 |
| 2026-10-02 00:00 |
23:54:49.80 |
+13:05:17.0 |
HIP 117899 |
7.61 |
| 2026-10-02 12:00 |
23:54:46.59 |
+13:04:57.1 |
HIP 117899 |
8.02 |
| 2026-10-03 00:00 |
23:54:43.38 |
+13:04:37.1 |
HIP 117899 |
8.50 |
| 2026-10-03 12:00 |
23:54:40.17 |
+13:04:17.0 |
HIP 117899 |
9.04 |
| 2026-10-04 00:00 |
23:54:36.97 |
+13:03:56.9 |
HIP 117899 |
9.62 |
| 2026-10-04 12:00 |
23:54:33.78 |
+13:03:36.7 |
HIP 117899 |
10.24 |
| 2026-10-05 00:00 |
23:54:30.60 |
+13:03:16.4 |
HIP 117899 |
10.89 |
| 2026-10-05 12:00 |
23:54:27.42 |
+13:02:56.1 |
HIP 117899 |
11.56 |
| 2026-10-06 00:00 |
23:54:24.25 |
+13:02:35.7 |
HIP 117899 |
12.26 |
| 2026-10-06 12:00 |
23:54:21.09 |
+13:02:15.2 |
HIP 117899 |
12.97 |
| 2026-10-07 00:00 |
23:54:17.94 |
+13:01:54.7 |
HIP 117899 |
13.70 |
| 2026-10-07 12:00 |
23:54:14.79 |
+13:01:34.1 |
HIP 117899 |
14.44 |
| 2026-10-08 00:00 |
23:54:11.65 |
+13:01:13.5 |
HIP 117899 |
15.19 |
| 2026-10-08 12:00 |
23:54:08.53 |
+13:00:52.8 |
HIP 117899 |
15.94 |
| 2026-10-09 00:00 |
23:54:05.41 |
+13:00:32.0 |
HIP 117899 |
16.71 |
| 2026-10-09 12:00 |
23:54:02.30 |
+13:00:11.2 |
HIP 117899 |
17.48 |
| 2026-10-10 00:00 |
23:53:59.20 |
+12:59:50.4 |
HIP 117899 |
18.25 |
| 2026-10-10 12:00 |
23:53:56.11 |
+12:59:29.5 |
HIP 117899 |
19.03 |
| 2026-10-11 00:00 |
23:53:53.03 |
+12:59:08.5 |
HIP 117899 |
19.81 |