| 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) |
| 2026-05-12 00:00 |
06:42:27.76 |
-10:45:38.4 |
HIP 32131 |
2.38 |
| 2026-05-12 12:00 |
06:42:30.17 |
-10:45:17.8 |
HIP 32131 |
1.72 |
| 2026-05-13 00:00 |
06:42:32.61 |
-10:44:57.4 |
HIP 32131 |
1.09 |
| 2026-05-13 12:00 |
06:42:35.06 |
-10:44:37.2 |
HIP 32131 |
0.61 |
| 2026-05-14 00:00 |
06:42:37.54 |
-10:44:17.2 |
HIP 32131 |
0.70 |
| 2026-05-14 12:00 |
06:42:40.04 |
-10:43:57.4 |
HIP 32131 |
1.26 |
| 2026-05-15 00:00 |
06:42:42.56 |
-10:43:37.8 |
HIP 32131 |
1.91 |
| 2026-05-15 12:00 |
06:42:45.10 |
-10:43:18.4 |
HIP 32131 |
2.59 |
| 2026-05-16 00:00 |
06:42:47.66 |
-10:42:59.2 |
HIP 32131 |
3.28 |
| 2026-05-16 12:00 |
06:42:50.25 |
-10:42:40.2 |
HIP 32131 |
3.98 |
| 2026-05-17 00:00 |
06:42:52.85 |
-10:42:21.4 |
HIP 32131 |
4.68 |
| 2026-05-17 12:00 |
06:42:55.48 |
-10:42:02.9 |
HIP 32131 |
5.39 |
| 2026-05-18 00:00 |
06:42:58.12 |
-10:41:44.6 |
HIP 32131 |
6.10 |
| 2026-05-18 12:00 |
06:43:00.79 |
-10:41:26.4 |
HIP 32131 |
6.82 |
| 2026-05-19 00:00 |
06:43:03.47 |
-10:41:08.5 |
HIP 32131 |
7.54 |
| 2026-05-19 12:00 |
06:43:06.18 |
-10:40:50.9 |
HIP 32131 |
8.26 |
| 2026-05-20 00:00 |
06:43:08.91 |
-10:40:33.4 |
HIP 32131 |
8.99 |
| 2026-05-20 12:00 |
06:43:11.65 |
-10:40:16.1 |
HIP 32131 |
9.72 |
| 2026-05-21 00:00 |
06:43:14.41 |
-10:39:59.1 |
HIP 32131 |
10.45 |
| 2026-05-21 12:00 |
06:43:17.20 |
-10:39:42.3 |
HIP 32131 |
11.18 |
| 2026-05-22 00:00 |
06:43:20.00 |
-10:39:25.7 |
HIP 32131 |
11.92 |
| 2026-05-22 12:00 |
06:43:22.82 |
-10:39:09.3 |
HIP 32131 |
12.66 |
| 2026-05-23 00:00 |
06:43:25.66 |
-10:38:53.2 |
HIP 32131 |
13.40 |
| 2026-05-23 12:00 |
06:43:28.51 |
-10:38:37.3 |
HIP 32131 |
14.15 |
| 2026-05-24 00:00 |
06:43:31.39 |
-10:38:21.6 |
HIP 32131 |
14.90 |
| 2026-05-24 12:00 |
06:43:34.28 |
-10:38:06.1 |
HIP 32131 |
15.65 |
| 2026-05-25 00:00 |
06:43:37.18 |
-10:37:50.9 |
HIP 32131 |
16.40 |
| 2026-05-25 12:00 |
06:43:40.11 |
-10:37:35.8 |
HIP 32131 |
17.16 |
| 2026-05-26 00:00 |
06:43:43.05 |
-10:37:21.0 |
HIP 32131 |
17.92 |
| 2026-05-26 12:00 |
06:43:46.01 |
-10:37:06.5 |
HIP 32131 |
18.68 |
| 2026-05-27 00:00 |
06:43:48.99 |
-10:36:52.1 |
HIP 32131 |
19.44 |
| 2026-05-27 12:00 |
06:43:51.98 |
-10:36:38.0 |
HIP 32131 |
20.21 |
| 2026-05-28 00:00 |
06:43:54.98 |
-10:36:24.1 |
HIP 32131 |
20.98 |
| 2026-05-28 12:00 |
06:43:58.01 |
-10:36:10.5 |
HIP 32131 |
21.75 |
| 2026-05-29 00:00 |
06:44:01.05 |
-10:35:57.1 |
HIP 32131 |
22.52 |
| 2026-05-29 12:00 |
06:44:04.10 |
-10:35:43.9 |
HIP 32131 |
23.30 |
| 2026-05-30 00:00 |
06:44:07.17 |
-10:35:30.9 |
HIP 32131 |
24.08 |
| 2026-05-30 12:00 |
06:44:10.26 |
-10:35:18.2 |
HIP 32255 |
24.67 |
| 2026-05-31 00:00 |
06:44:13.36 |
-10:35:05.7 |
HIP 32255 |
24.89 |
| 2026-05-31 12:00 |
06:44:16.47 |
-10:34:53.4 |
HIP 32255 |
25.14 |
| 2026-06-01 00:00 |
06:44:19.60 |
-10:34:41.4 |
HIP 32255 |
25.41 |
| 2026-06-01 12:00 |
06:44:22.74 |
-10:34:29.6 |
HIP 32255 |
25.69 |
| 2026-06-02 00:00 |
06:44:25.90 |
-10:34:18.1 |
HIP 32255 |
25.99 |