C/2011 W3 (Lovejoy)
| 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
$$
M_a = (15.970 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.970 |
| 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 |
2011-12-14 |
+5.8836 |
+3.679 |
| 2011-12-14 |
2011-12-15 |
-12.7406 |
-14.889 |
| 2011-12-16 |
2011-12-16 |
-24.1088 |
-29.195 |
| 2011-12-16 |
2012-01-16 |
-1.5859 |
-5.993 |
| 2012-01-16 |
2012-01-31 |
+30.6612 |
-6.939 |
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 |
06:44:01.22 |
-12:18:44.8 |
HIP 32183 |
34.45 |
| 2026-02-03 12:00 |
06:43:57.90 |
-12:18:22.9 |
HIP 32183 |
33.82 |
| 2026-02-04 00:00 |
06:43:54.59 |
-12:18:00.9 |
HIP 32183 |
33.19 |
| 2026-02-04 12:00 |
06:43:51.31 |
-12:17:38.6 |
HIP 32183 |
32.58 |
| 2026-02-05 00:00 |
06:43:48.05 |
-12:17:16.1 |
HIP 32183 |
31.98 |
| 2026-02-05 12:00 |
06:43:44.80 |
-12:16:53.4 |
HIP 32183 |
31.39 |
| 2026-02-06 00:00 |
06:43:41.58 |
-12:16:30.5 |
HIP 32183 |
30.81 |
| 2026-02-06 12:00 |
06:43:38.39 |
-12:16:07.3 |
HIP 32183 |
30.25 |
| 2026-02-07 00:00 |
06:43:35.21 |
-12:15:44.0 |
HIP 32183 |
29.69 |
| 2026-02-07 12:00 |
06:43:32.06 |
-12:15:20.4 |
HIP 32183 |
29.15 |
| 2026-02-08 00:00 |
06:43:28.93 |
-12:14:56.7 |
HIP 32183 |
28.63 |
| 2026-02-08 12:00 |
06:43:25.82 |
-12:14:32.7 |
HIP 32183 |
28.11 |
| 2026-02-09 00:00 |
06:43:22.74 |
-12:14:08.6 |
HIP 32183 |
27.61 |
| 2026-02-09 12:00 |
06:43:19.68 |
-12:13:44.2 |
HIP 32183 |
27.13 |
| 2026-02-10 00:00 |
06:43:16.64 |
-12:13:19.6 |
HIP 32183 |
26.66 |
| 2026-02-10 12:00 |
06:43:13.63 |
-12:12:54.9 |
HIP 32183 |
26.21 |
| 2026-02-11 00:00 |
06:43:10.64 |
-12:12:29.9 |
HIP 32183 |
25.77 |
| 2026-02-11 12:00 |
06:43:07.68 |
-12:12:04.8 |
HIP 32183 |
25.36 |
| 2026-02-12 00:00 |
06:43:04.74 |
-12:11:39.4 |
HIP 32183 |
24.95 |
| 2026-02-12 12:00 |
06:43:01.83 |
-12:11:13.9 |
HIP 32183 |
24.57 |
| 2026-02-13 00:00 |
06:42:58.94 |
-12:10:48.2 |
HIP 32183 |
24.21 |
| 2026-02-13 12:00 |
06:42:56.07 |
-12:10:22.3 |
HIP 32183 |
23.86 |
| 2026-02-14 00:00 |
06:42:53.24 |
-12:09:56.3 |
HIP 32183 |
23.54 |
| 2026-02-14 12:00 |
06:42:50.42 |
-12:09:30.0 |
HIP 32183 |
23.23 |
| 2026-02-15 00:00 |
06:42:47.64 |
-12:09:03.6 |
HIP 32183 |
22.95 |
| 2026-02-15 12:00 |
06:42:44.88 |
-12:08:37.0 |
HIP 32183 |
22.69 |
| 2026-02-16 00:00 |
06:42:42.15 |
-12:08:10.3 |
HIP 32183 |
22.44 |
| 2026-02-16 12:00 |
06:42:39.44 |
-12:07:43.3 |
HIP 32160 |
22.17 |
| 2026-02-17 00:00 |
06:42:36.76 |
-12:07:16.2 |
HIP 32160 |
21.86 |
| 2026-02-17 12:00 |
06:42:34.11 |
-12:06:49.0 |
HIP 32160 |
21.58 |
| 2026-02-18 00:00 |
06:42:31.48 |
-12:06:21.6 |
HIP 32160 |
21.32 |
| 2026-02-18 12:00 |
06:42:28.89 |
-12:05:54.0 |
HIP 32160 |
21.08 |
| 2026-02-19 00:00 |
06:42:26.32 |
-12:05:26.3 |
HIP 32160 |
20.86 |
| 2026-02-19 12:00 |
06:42:23.78 |
-12:04:58.4 |
HIP 32160 |
20.66 |
| 2026-02-20 00:00 |
06:42:21.26 |
-12:04:30.4 |
HIP 32160 |
20.48 |
| 2026-02-20 12:00 |
06:42:18.78 |
-12:04:02.2 |
HIP 32160 |
20.33 |
| 2026-02-21 00:00 |
06:42:16.32 |
-12:03:33.9 |
HIP 32160 |
20.20 |
| 2026-02-21 12:00 |
06:42:13.89 |
-12:03:05.4 |
HIP 32160 |
20.09 |
| 2026-02-22 00:00 |
06:42:11.49 |
-12:02:36.8 |
HIP 31976 |
19.95 |
| 2026-02-22 12:00 |
06:42:09.12 |
-12:02:08.1 |
HIP 31976 |
19.64 |
| 2026-02-23 00:00 |
06:42:06.78 |
-12:01:39.2 |
HIP 31976 |
19.35 |
| 2026-02-23 12:00 |
06:42:04.47 |
-12:01:10.2 |
HIP 31976 |
19.10 |
| 2026-02-24 00:00 |
06:42:02.19 |
-12:00:41.1 |
HIP 31976 |
18.88 |