| Parameter |
Value |
| Designation |
C/2007 E1 (Garradd) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2007-05-23T19:56:03.209280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:05Z |
| Obs used |
1017 |
| NEO |
- |
| M1 |
13.900 |
| K1 |
9.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2007-05-21.0000000 |
| e |
0.98021742 |
| q (au) |
1.285863 |
| a (au) |
64.999734 |
| i (deg) |
174.393993 |
| Ω (om, deg) |
153.826639 |
| ω (w, deg) |
7.102013 |
| M (ma, deg) |
359.994676 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.954 + 4.197\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.954 |
| n |
4.197 |
| gf |
1.000 |
| gb |
-0.945 |
| k |
1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2007-03-13 |
2007-05-20 |
+25.1523 |
-4.738 |
| 2007-05-26 |
2007-12-27 |
+6.4556 |
-2.958 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
23:06:56.29 |
-04:28:49.9 |
HIP 114120 |
17.16 |
| 2026-07-29 12:00 |
23:06:53.81 |
-04:29:05.1 |
HIP 114120 |
17.29 |
| 2026-07-30 00:00 |
23:06:51.31 |
-04:29:20.3 |
HIP 114120 |
17.45 |
| 2026-07-30 12:00 |
23:06:48.80 |
-04:29:35.7 |
HIP 114120 |
17.63 |
| 2026-07-31 00:00 |
23:06:46.27 |
-04:29:51.2 |
HIP 114120 |
17.83 |
| 2026-07-31 12:00 |
23:06:43.73 |
-04:30:06.8 |
HIP 114120 |
18.07 |
| 2026-08-01 00:00 |
23:06:41.17 |
-04:30:22.4 |
HIP 114120 |
18.32 |
| 2026-08-01 12:00 |
23:06:38.59 |
-04:30:38.2 |
HIP 114120 |
18.60 |
| 2026-08-02 00:00 |
23:06:36.00 |
-04:30:54.1 |
HIP 114120 |
18.91 |
| 2026-08-02 12:00 |
23:06:33.39 |
-04:31:10.1 |
HIP 114120 |
19.23 |
| 2026-08-03 00:00 |
23:06:30.76 |
-04:31:26.2 |
HIP 114120 |
19.58 |
| 2026-08-03 12:00 |
23:06:28.12 |
-04:31:42.5 |
HIP 114120 |
19.95 |
| 2026-08-04 00:00 |
23:06:25.47 |
-04:31:58.8 |
HIP 114120 |
20.34 |
| 2026-08-04 12:00 |
23:06:22.80 |
-04:32:15.2 |
HIP 114120 |
20.75 |
| 2026-08-05 00:00 |
23:06:20.11 |
-04:32:31.7 |
HIP 114120 |
21.18 |
| 2026-08-05 12:00 |
23:06:17.41 |
-04:32:48.3 |
HIP 114120 |
21.63 |
| 2026-08-06 00:00 |
23:06:14.70 |
-04:33:05.0 |
HIP 114120 |
22.09 |
| 2026-08-06 12:00 |
23:06:11.97 |
-04:33:21.8 |
HIP 114120 |
22.57 |
| 2026-08-07 00:00 |
23:06:09.23 |
-04:33:38.7 |
HIP 114118 |
23.07 |
| 2026-08-07 12:00 |
23:06:06.47 |
-04:33:55.7 |
HIP 114118 |
23.57 |
| 2026-08-08 00:00 |
23:06:03.70 |
-04:34:12.8 |
HIP 114118 |
24.10 |
| 2026-08-08 12:00 |
23:06:00.92 |
-04:34:30.0 |
HIP 114118 |
24.63 |
| 2026-08-09 00:00 |
23:05:58.12 |
-04:34:47.3 |
HIP 114118 |
25.18 |
| 2026-08-09 12:00 |
23:05:55.31 |
-04:35:04.6 |
HIP 114118 |
25.75 |
| 2026-08-10 00:00 |
23:05:52.49 |
-04:35:22.1 |
HIP 114118 |
26.32 |
| 2026-08-10 12:00 |
23:05:49.65 |
-04:35:39.6 |
HIP 114118 |
26.91 |
| 2026-08-11 00:00 |
23:05:46.80 |
-04:35:57.2 |
HIP 114118 |
27.51 |
| 2026-08-11 12:00 |
23:05:43.94 |
-04:36:14.9 |
HIP 114118 |
28.12 |
| 2026-08-12 00:00 |
23:05:41.07 |
-04:36:32.7 |
HIP 113896 |
28.21 |
| 2026-08-12 12:00 |
23:05:38.19 |
-04:36:50.6 |
HIP 113896 |
27.43 |
| 2026-08-13 00:00 |
23:05:35.29 |
-04:37:08.5 |
HIP 113896 |
26.65 |
| 2026-08-13 12:00 |
23:05:32.38 |
-04:37:26.6 |
HIP 113896 |
25.86 |
| 2026-08-14 00:00 |
23:05:29.46 |
-04:37:44.7 |
HIP 113896 |
25.08 |
| 2026-08-14 12:00 |
23:05:26.53 |
-04:38:02.9 |
HIP 113896 |
24.29 |
| 2026-08-15 00:00 |
23:05:23.59 |
-04:38:21.1 |
HIP 113896 |
23.49 |
| 2026-08-15 12:00 |
23:05:20.64 |
-04:38:39.5 |
HIP 113896 |
22.70 |
| 2026-08-16 00:00 |
23:05:17.68 |
-04:38:57.9 |
HIP 113896 |
21.90 |
| 2026-08-16 12:00 |
23:05:14.70 |
-04:39:16.3 |
HIP 113896 |
21.09 |
| 2026-08-17 00:00 |
23:05:11.72 |
-04:39:34.9 |
HIP 113896 |
20.29 |
| 2026-08-17 12:00 |
23:05:08.73 |
-04:39:53.5 |
HIP 113896 |
19.48 |
| 2026-08-18 00:00 |
23:05:05.73 |
-04:40:12.2 |
HIP 113896 |
18.67 |
| 2026-08-18 12:00 |
23:05:02.72 |
-04:40:30.9 |
HIP 113896 |
17.86 |
| 2026-08-19 00:00 |
23:04:59.70 |
-04:40:49.7 |
HIP 113896 |
17.05 |