| 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) |
| 2026-06-01 00:00 |
02:44:52.28 |
+55:31:15.0 |
HIP 12816 |
13.17 |
| 2026-06-01 12:00 |
02:44:56.75 |
+55:31:34.9 |
HIP 12816 |
12.90 |
| 2026-06-02 00:00 |
02:45:01.20 |
+55:31:55.0 |
HIP 12816 |
12.65 |
| 2026-06-02 12:00 |
02:45:05.63 |
+55:32:15.3 |
HIP 12816 |
12.44 |
| 2026-06-03 00:00 |
02:45:10.04 |
+55:32:35.7 |
HIP 12816 |
12.26 |
| 2026-06-03 12:00 |
02:45:14.43 |
+55:32:56.3 |
HIP 12816 |
12.12 |
| 2026-06-04 00:00 |
02:45:18.81 |
+55:33:17.1 |
HIP 12816 |
12.02 |
| 2026-06-04 12:00 |
02:45:23.16 |
+55:33:38.0 |
HIP 12816 |
11.95 |
| 2026-06-05 00:00 |
02:45:27.50 |
+55:33:59.0 |
HIP 12816 |
11.92 |
| 2026-06-05 12:00 |
02:45:31.82 |
+55:34:20.2 |
HIP 12816 |
11.93 |
| 2026-06-06 00:00 |
02:45:36.12 |
+55:34:41.6 |
HIP 12816 |
11.97 |
| 2026-06-06 12:00 |
02:45:40.39 |
+55:35:03.1 |
HIP 12816 |
12.06 |
| 2026-06-07 00:00 |
02:45:44.65 |
+55:35:24.7 |
HIP 12816 |
12.18 |
| 2026-06-07 12:00 |
02:45:48.89 |
+55:35:46.5 |
HIP 12816 |
12.33 |
| 2026-06-08 00:00 |
02:45:53.10 |
+55:36:08.5 |
HIP 12816 |
12.52 |
| 2026-06-08 12:00 |
02:45:57.30 |
+55:36:30.6 |
HIP 12816 |
12.74 |
| 2026-06-09 00:00 |
02:46:01.47 |
+55:36:52.8 |
HIP 12816 |
12.98 |
| 2026-06-09 12:00 |
02:46:05.62 |
+55:37:15.2 |
HIP 12816 |
13.26 |
| 2026-06-10 00:00 |
02:46:09.75 |
+55:37:37.7 |
HIP 12816 |
13.56 |
| 2026-06-10 12:00 |
02:46:13.85 |
+55:38:00.3 |
HIP 12816 |
13.89 |
| 2026-06-11 00:00 |
02:46:17.94 |
+55:38:23.1 |
HIP 13063 |
13.83 |
| 2026-06-11 12:00 |
02:46:22.00 |
+55:38:46.1 |
HIP 13063 |
13.31 |
| 2026-06-12 00:00 |
02:46:26.04 |
+55:39:09.1 |
HIP 13063 |
12.81 |
| 2026-06-12 12:00 |
02:46:30.05 |
+55:39:32.3 |
HIP 13063 |
12.34 |
| 2026-06-13 00:00 |
02:46:34.04 |
+55:39:55.7 |
HIP 13063 |
11.88 |
| 2026-06-13 12:00 |
02:46:38.01 |
+55:40:19.1 |
HIP 13063 |
11.46 |
| 2026-06-14 00:00 |
02:46:41.95 |
+55:40:42.7 |
HIP 13063 |
11.06 |
| 2026-06-14 12:00 |
02:46:45.86 |
+55:41:06.4 |
HIP 13063 |
10.70 |
| 2026-06-15 00:00 |
02:46:49.76 |
+55:41:30.3 |
HIP 13063 |
10.37 |
| 2026-06-15 12:00 |
02:46:53.62 |
+55:41:54.2 |
HIP 13063 |
10.08 |
| 2026-06-16 00:00 |
02:46:57.46 |
+55:42:18.3 |
HIP 13063 |
9.83 |
| 2026-06-16 12:00 |
02:47:01.28 |
+55:42:42.5 |
HIP 13063 |
9.63 |
| 2026-06-17 00:00 |
02:47:05.07 |
+55:43:06.9 |
HIP 13063 |
9.48 |
| 2026-06-17 12:00 |
02:47:08.83 |
+55:43:31.3 |
HIP 13063 |
9.38 |
| 2026-06-18 00:00 |
02:47:12.57 |
+55:43:55.9 |
HIP 13088 |
9.08 |
| 2026-06-18 12:00 |
02:47:16.27 |
+55:44:20.5 |
HIP 13088 |
8.47 |
| 2026-06-19 00:00 |
02:47:19.96 |
+55:44:45.3 |
HIP 13088 |
7.87 |
| 2026-06-19 12:00 |
02:47:23.61 |
+55:45:10.2 |
HIP 13088 |
7.29 |
| 2026-06-20 00:00 |
02:47:27.24 |
+55:45:35.2 |
HIP 13088 |
6.72 |
| 2026-06-20 12:00 |
02:47:30.84 |
+55:46:00.3 |
HIP 13088 |
6.18 |
| 2026-06-21 00:00 |
02:47:34.41 |
+55:46:25.5 |
HIP 13088 |
5.66 |
| 2026-06-21 12:00 |
02:47:37.95 |
+55:46:50.8 |
HIP 13088 |
5.18 |
| 2026-06-22 00:00 |
02:47:41.46 |
+55:47:16.2 |
HIP 13088 |
4.75 |