C/2007 E2 (Lovejoy)
| Parameter |
Value |
| Designation |
C/2007 E2 (Lovejoy) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2007-03-27T12:01:31.946880Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:05Z |
| Obs used |
1648 |
| NEO |
- |
| M1 |
10.300 |
| K1 |
17.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2007-05-15.0000000 |
| e |
0.99917565 |
| q (au) |
1.092938 |
| a (au) |
1325.822845 |
| i (deg) |
95.882901 |
| Ω (om, deg) |
232.431837 |
| ω (w, deg) |
340.533777 |
| M (ma, deg) |
0.000990 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.262 + 3.304\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.262 |
| n |
3.304 |
| gf |
1.000 |
| gb |
-0.728 |
| k |
0.800 |
| 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 |
| 2007-03-27 |
2007-08-23 |
+7.4238 |
-2.181 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
02:30:05.63 |
+55:56:00.9 |
HIP 11730 |
11.69 |
| 2026-02-03 12:00 |
02:30:06.05 |
+55:55:29.2 |
HIP 11730 |
11.78 |
| 2026-02-04 00:00 |
02:30:06.53 |
+55:54:57.7 |
HIP 11730 |
11.90 |
| 2026-02-04 12:00 |
02:30:07.05 |
+55:54:26.4 |
HIP 11730 |
12.03 |
| 2026-02-05 00:00 |
02:30:07.61 |
+55:53:55.1 |
HIP 11730 |
12.17 |
| 2026-02-05 12:00 |
02:30:08.22 |
+55:53:24.0 |
HIP 11730 |
12.33 |
| 2026-02-06 00:00 |
02:30:08.87 |
+55:52:53.0 |
HIP 11730 |
12.50 |
| 2026-02-06 12:00 |
02:30:09.57 |
+55:52:22.2 |
HIP 11730 |
12.68 |
| 2026-02-07 00:00 |
02:30:10.31 |
+55:51:51.5 |
HIP 11730 |
12.88 |
| 2026-02-07 12:00 |
02:30:11.10 |
+55:51:21.0 |
HIP 11730 |
13.09 |
| 2026-02-08 00:00 |
02:30:11.94 |
+55:50:50.6 |
HIP 11730 |
13.30 |
| 2026-02-08 12:00 |
02:30:12.81 |
+55:50:20.4 |
HIP 11730 |
13.53 |
| 2026-02-09 00:00 |
02:30:13.74 |
+55:49:50.3 |
HIP 11730 |
13.77 |
| 2026-02-09 12:00 |
02:30:14.70 |
+55:49:20.3 |
HIP 11730 |
14.02 |
| 2026-02-10 00:00 |
02:30:15.71 |
+55:48:50.5 |
HIP 11730 |
14.27 |
| 2026-02-10 12:00 |
02:30:16.77 |
+55:48:20.9 |
HIP 11730 |
14.53 |
| 2026-02-11 00:00 |
02:30:17.87 |
+55:47:51.4 |
HIP 11730 |
14.80 |
| 2026-02-11 12:00 |
02:30:19.01 |
+55:47:22.1 |
HIP 11730 |
15.08 |
| 2026-02-12 00:00 |
02:30:20.19 |
+55:46:53.0 |
HIP 11696 |
14.61 |
| 2026-02-12 12:00 |
02:30:21.42 |
+55:46:24.0 |
HIP 11696 |
14.09 |
| 2026-02-13 00:00 |
02:30:22.70 |
+55:45:55.2 |
HIP 11696 |
13.58 |
| 2026-02-13 12:00 |
02:30:24.01 |
+55:45:26.6 |
HIP 11696 |
13.07 |
| 2026-02-14 00:00 |
02:30:25.37 |
+55:44:58.1 |
HIP 11696 |
12.56 |
| 2026-02-14 12:00 |
02:30:26.78 |
+55:44:29.8 |
HIP 11696 |
12.06 |
| 2026-02-15 00:00 |
02:30:28.22 |
+55:44:01.7 |
HIP 11696 |
11.55 |
| 2026-02-15 12:00 |
02:30:29.71 |
+55:43:33.8 |
HIP 11696 |
11.04 |
| 2026-02-16 00:00 |
02:30:31.24 |
+55:43:06.0 |
HIP 11696 |
10.54 |
| 2026-02-16 12:00 |
02:30:32.82 |
+55:42:38.4 |
HIP 11696 |
10.04 |
| 2026-02-17 00:00 |
02:30:34.43 |
+55:42:11.0 |
HIP 11696 |
9.54 |
| 2026-02-17 12:00 |
02:30:36.09 |
+55:41:43.8 |
HIP 11696 |
9.05 |
| 2026-02-18 00:00 |
02:30:37.79 |
+55:41:16.8 |
HIP 11696 |
8.55 |
| 2026-02-18 12:00 |
02:30:39.53 |
+55:40:49.9 |
HIP 11696 |
8.07 |
| 2026-02-19 00:00 |
02:30:41.31 |
+55:40:23.3 |
HIP 11696 |
7.58 |
| 2026-02-19 12:00 |
02:30:43.14 |
+55:39:56.8 |
HIP 11696 |
7.11 |
| 2026-02-20 00:00 |
02:30:45.00 |
+55:39:30.6 |
HIP 11696 |
6.64 |
| 2026-02-20 12:00 |
02:30:46.91 |
+55:39:04.5 |
HIP 11696 |
6.18 |
| 2026-02-21 00:00 |
02:30:48.86 |
+55:38:38.6 |
HIP 11696 |
5.73 |
| 2026-02-21 12:00 |
02:30:50.84 |
+55:38:12.9 |
HIP 11696 |
5.30 |
| 2026-02-22 00:00 |
02:30:52.87 |
+55:37:47.5 |
HIP 11696 |
4.88 |
| 2026-02-22 12:00 |
02:30:54.94 |
+55:37:22.2 |
HIP 11696 |
4.49 |
| 2026-02-23 00:00 |
02:30:57.05 |
+55:36:57.1 |
HIP 11696 |
4.14 |
| 2026-02-23 12:00 |
02:30:59.19 |
+55:36:32.3 |
HIP 11696 |
3.82 |
| 2026-02-24 00:00 |
02:31:01.38 |
+55:36:07.6 |
HIP 11696 |
3.55 |