| Parameter |
Value |
| Designation |
C/2011 W3 (Lovejoy) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2011-12-16T00:17:00.297600Z |
| Orbit solution date (soln_date, UTC) |
2012-06-04T12:31:54Z |
| Obs used |
123 |
| NEO |
- |
| M1 |
15.300 |
| K1 |
9.300 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-12-06.0000000 |
| e |
0.99992942 |
| q (au) |
0.005554 |
| a (au) |
78.682940 |
| i (deg) |
134.355811 |
| Ω (om, deg) |
326.369147 |
| ω (w, deg) |
53.509212 |
| M (ma, deg) |
359.985862 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.974 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.974 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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 |
| 2011-11-27 |
2011-12-13 |
+6.4650 |
+3.679 |
| 2011-12-13 |
2011-12-15 |
-5.1086 |
-3.970 |
| 2011-12-16 |
2011-12-21 |
-9.5415 |
-11.600 |
| 2011-12-21 |
2012-01-31 |
+3.0683 |
-4.819 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
06:40:42.81 |
-11:29:13.7 |
HIP 32029 |
14.90 |
| 2026-03-26 12:00 |
06:40:42.49 |
-11:28:41.5 |
HIP 32029 |
14.59 |
| 2026-03-27 00:00 |
06:40:42.20 |
-11:28:09.4 |
HIP 32029 |
14.28 |
| 2026-03-27 12:00 |
06:40:41.95 |
-11:27:37.2 |
HIP 32029 |
13.98 |
| 2026-03-28 00:00 |
06:40:41.73 |
-11:27:05.1 |
HIP 32029 |
13.69 |
| 2026-03-28 12:00 |
06:40:41.54 |
-11:26:33.1 |
HIP 32029 |
13.41 |
| 2026-03-29 00:00 |
06:40:41.38 |
-11:26:01.1 |
HIP 32029 |
13.14 |
| 2026-03-29 12:00 |
06:40:41.26 |
-11:25:29.1 |
HIP 32029 |
12.88 |
| 2026-03-30 00:00 |
06:40:41.17 |
-11:24:57.2 |
HIP 32029 |
12.63 |
| 2026-03-30 12:00 |
06:40:41.12 |
-11:24:25.3 |
HIP 32029 |
12.39 |
| 2026-03-31 00:00 |
06:40:41.09 |
-11:23:53.5 |
HIP 32029 |
12.16 |
| 2026-03-31 12:00 |
06:40:41.10 |
-11:23:21.7 |
HIP 32029 |
11.94 |
| 2026-04-01 00:00 |
06:40:41.14 |
-11:22:49.9 |
HIP 32029 |
11.74 |
| 2026-04-01 12:00 |
06:40:41.22 |
-11:22:18.3 |
HIP 32029 |
11.55 |
| 2026-04-02 00:00 |
06:40:41.32 |
-11:21:46.6 |
HIP 32029 |
11.37 |
| 2026-04-02 12:00 |
06:40:41.46 |
-11:21:15.1 |
HIP 32029 |
11.21 |
| 2026-04-03 00:00 |
06:40:41.63 |
-11:20:43.6 |
HIP 32029 |
11.06 |
| 2026-04-03 12:00 |
06:40:41.84 |
-11:20:12.1 |
HIP 32029 |
10.93 |
| 2026-04-04 00:00 |
06:40:42.07 |
-11:19:40.7 |
HIP 32029 |
10.82 |
| 2026-04-04 12:00 |
06:40:42.34 |
-11:19:09.4 |
HIP 32029 |
10.72 |
| 2026-04-05 00:00 |
06:40:42.64 |
-11:18:38.2 |
HIP 32029 |
10.64 |
| 2026-04-05 12:00 |
06:40:42.98 |
-11:18:07.0 |
HIP 32029 |
10.57 |
| 2026-04-06 00:00 |
06:40:43.34 |
-11:17:35.9 |
HIP 32029 |
10.53 |
| 2026-04-06 12:00 |
06:40:43.74 |
-11:17:04.9 |
HIP 32029 |
10.50 |
| 2026-04-07 00:00 |
06:40:44.17 |
-11:16:33.9 |
HIP 32029 |
10.49 |
| 2026-04-07 12:00 |
06:40:44.63 |
-11:16:03.1 |
HIP 32029 |
10.50 |
| 2026-04-08 00:00 |
06:40:45.13 |
-11:15:32.3 |
HIP 32029 |
10.53 |
| 2026-04-08 12:00 |
06:40:45.65 |
-11:15:01.6 |
HIP 32029 |
10.57 |
| 2026-04-09 00:00 |
06:40:46.21 |
-11:14:30.9 |
HIP 32029 |
10.64 |
| 2026-04-09 12:00 |
06:40:46.80 |
-11:14:00.4 |
HIP 32029 |
10.72 |
| 2026-04-10 00:00 |
06:40:47.42 |
-11:13:30.0 |
HIP 32029 |
10.82 |
| 2026-04-10 12:00 |
06:40:48.07 |
-11:12:59.6 |
HIP 32029 |
10.94 |
| 2026-04-11 00:00 |
06:40:48.76 |
-11:12:29.4 |
HIP 32029 |
11.07 |
| 2026-04-11 12:00 |
06:40:49.47 |
-11:11:59.2 |
HIP 32029 |
11.22 |
| 2026-04-12 00:00 |
06:40:50.22 |
-11:11:29.1 |
HIP 32029 |
11.39 |
| 2026-04-12 12:00 |
06:40:51.00 |
-11:10:59.2 |
HIP 32029 |
11.57 |
| 2026-04-13 00:00 |
06:40:51.80 |
-11:10:29.3 |
HIP 32029 |
11.77 |
| 2026-04-13 12:00 |
06:40:52.65 |
-11:09:59.5 |
HIP 32029 |
11.98 |
| 2026-04-14 00:00 |
06:40:53.52 |
-11:09:29.9 |
HIP 32029 |
12.21 |
| 2026-04-14 12:00 |
06:40:54.42 |
-11:09:00.4 |
HIP 32029 |
12.44 |
| 2026-04-15 00:00 |
06:40:55.35 |
-11:08:30.9 |
HIP 32029 |
12.69 |
| 2026-04-15 12:00 |
06:40:56.32 |
-11:08:01.6 |
HIP 32029 |
12.96 |
| 2026-04-16 00:00 |
06:40:57.31 |
-11:07:32.4 |
HIP 32029 |
13.23 |