| Parameter |
Value |
| Designation |
259P/Garradd |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2013-01-25T05:54:24.387840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:08Z |
| Obs used |
68 |
| NEO |
- |
| M1 |
13.700 |
| K1 |
22.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-02-26.0000000 |
| e |
0.34152970 |
| q (au) |
1.795939 |
| a (au) |
2.727441 |
| i (deg) |
15.898537 |
| Ω (om, deg) |
51.969696 |
| ω (w, deg) |
256.590906 |
| M (ma, deg) |
206.996592 |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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 |
18:34:37.28 |
-28:34:18.7 |
HIP 91033 |
14.59 |
| 2026-03-26 12:00 |
18:35:36.27 |
-28:37:39.0 |
HIP 91273 |
20.31 |
| 2026-03-27 00:00 |
18:36:35.21 |
-28:40:59.7 |
HIP 91273 |
11.94 |
| 2026-03-27 12:00 |
18:37:34.10 |
-28:44:20.8 |
HIP 91273 |
15.17 |
| 2026-03-28 00:00 |
18:38:32.93 |
-28:47:42.3 |
HIP 91273 |
25.96 |
| 2026-03-28 12:00 |
18:39:31.71 |
-28:51:04.2 |
HIP 91640 |
23.42 |
| 2026-03-29 00:00 |
18:40:30.43 |
-28:54:26.6 |
HIP 91640 |
11.59 |
| 2026-03-29 12:00 |
18:41:29.10 |
-28:57:49.5 |
HIP 91640 |
8.61 |
| 2026-03-30 00:00 |
18:42:27.70 |
-29:01:12.9 |
HIP 91640 |
19.13 |
| 2026-03-30 12:00 |
18:43:26.25 |
-29:04:36.8 |
HIP 91894 |
16.95 |
| 2026-03-31 00:00 |
18:44:24.74 |
-29:08:01.2 |
HIP 91894 |
13.00 |
| 2026-03-31 12:00 |
18:45:23.16 |
-29:11:26.3 |
HIP 91894 |
19.98 |
| 2026-04-01 00:00 |
18:46:21.52 |
-29:14:51.8 |
HIP 92134 |
16.01 |
| 2026-04-01 12:00 |
18:47:19.82 |
-29:18:18.0 |
HIP 92134 |
14.31 |
| 2026-04-02 00:00 |
18:48:18.05 |
-29:21:44.8 |
HIP 92134 |
22.32 |
| 2026-04-02 12:00 |
18:49:16.22 |
-29:25:12.2 |
HIP 92363 |
20.66 |
| 2026-04-03 00:00 |
18:50:14.32 |
-29:28:40.3 |
HIP 92564 |
21.66 |
| 2026-04-03 12:00 |
18:51:12.34 |
-29:32:09.1 |
HIP 92564 |
14.75 |
| 2026-04-04 00:00 |
18:52:10.30 |
-29:35:38.5 |
HIP 92643 |
14.12 |
| 2026-04-04 12:00 |
18:53:08.18 |
-29:39:08.7 |
HIP 92643 |
17.72 |
| 2026-04-05 00:00 |
18:54:05.99 |
-29:42:39.7 |
HIP 92643 |
27.74 |
| 2026-04-05 12:00 |
18:55:03.73 |
-29:46:11.3 |
HIP 92966 |
17.87 |
| 2026-04-06 00:00 |
18:56:01.38 |
-29:49:43.8 |
HIP 92966 |
9.49 |
| 2026-04-06 12:00 |
18:56:58.96 |
-29:53:17.1 |
HIP 93002 |
8.86 |
| 2026-04-07 00:00 |
18:57:56.46 |
-29:56:51.2 |
HIP 93002 |
15.90 |
| 2026-04-07 12:00 |
18:58:53.87 |
-30:00:26.2 |
HIP 93002 |
27.59 |
| 2026-04-08 00:00 |
18:59:51.20 |
-30:04:02.0 |
HIP 93181 |
36.47 |
| 2026-04-08 12:00 |
19:00:48.44 |
-30:07:38.7 |
HIP 93506 |
27.74 |
| 2026-04-09 00:00 |
19:01:45.59 |
-30:11:16.4 |
HIP 93506 |
21.53 |
| 2026-04-09 12:00 |
19:02:42.66 |
-30:14:55.0 |
HIP 93506 |
22.15 |
| 2026-04-10 00:00 |
19:03:39.63 |
-30:18:34.6 |
HIP 93506 |
29.14 |
| 2026-04-10 12:00 |
19:04:36.50 |
-30:22:15.1 |
HIP 93670 |
26.69 |
| 2026-04-11 00:00 |
19:05:33.28 |
-30:25:56.7 |
HIP 93670 |
26.60 |
| 2026-04-11 12:00 |
19:06:29.96 |
-30:29:39.3 |
HIP 93923 |
21.55 |
| 2026-04-12 00:00 |
19:07:26.54 |
-30:33:23.0 |
HIP 93923 |
13.79 |
| 2026-04-12 12:00 |
19:08:23.02 |
-30:37:07.7 |
HIP 94108 |
13.28 |
| 2026-04-13 00:00 |
19:09:19.40 |
-30:40:53.6 |
HIP 94108 |
2.44 |
| 2026-04-13 12:00 |
19:10:15.66 |
-30:44:40.6 |
HIP 94108 |
12.56 |
| 2026-04-14 00:00 |
19:11:11.82 |
-30:48:28.8 |
HIP 94312 |
20.66 |
| 2026-04-14 12:00 |
19:12:07.87 |
-30:52:18.1 |
HIP 94312 |
16.14 |
| 2026-04-15 00:00 |
19:13:03.81 |
-30:56:08.7 |
HIP 94506 |
14.06 |
| 2026-04-15 12:00 |
19:13:59.62 |
-31:00:00.5 |
HIP 94506 |
1.58 |
| 2026-04-16 00:00 |
19:14:55.33 |
-31:03:53.5 |
HIP 94506 |
11.09 |