| 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) |
| 2026-07-29 00:00 |
06:51:00.44 |
-10:38:56.6 |
HIP 32848 |
3.46 |
| 2026-07-29 12:00 |
06:51:03.69 |
-10:39:12.6 |
HIP 32848 |
4.07 |
| 2026-07-30 00:00 |
06:51:06.93 |
-10:39:28.7 |
HIP 32848 |
4.75 |
| 2026-07-30 12:00 |
06:51:10.16 |
-10:39:45.1 |
HIP 32848 |
5.48 |
| 2026-07-31 00:00 |
06:51:13.38 |
-10:40:01.7 |
HIP 32848 |
6.22 |
| 2026-07-31 12:00 |
06:51:16.58 |
-10:40:18.5 |
HIP 32848 |
6.99 |
| 2026-08-01 00:00 |
06:51:19.77 |
-10:40:35.6 |
HIP 32848 |
7.77 |
| 2026-08-01 12:00 |
06:51:22.95 |
-10:40:52.8 |
HIP 32848 |
8.55 |
| 2026-08-02 00:00 |
06:51:26.11 |
-10:41:10.2 |
HIP 32848 |
9.34 |
| 2026-08-02 12:00 |
06:51:29.26 |
-10:41:27.8 |
HIP 32848 |
10.13 |
| 2026-08-03 00:00 |
06:51:32.40 |
-10:41:45.7 |
HIP 32848 |
10.93 |
| 2026-08-03 12:00 |
06:51:35.52 |
-10:42:03.7 |
HIP 32848 |
11.72 |
| 2026-08-04 00:00 |
06:51:38.62 |
-10:42:22.0 |
HIP 32848 |
12.52 |
| 2026-08-04 12:00 |
06:51:41.72 |
-10:42:40.4 |
HIP 32848 |
13.31 |
| 2026-08-05 00:00 |
06:51:44.80 |
-10:42:59.1 |
HIP 32848 |
14.11 |
| 2026-08-05 12:00 |
06:51:47.86 |
-10:43:17.9 |
HIP 32848 |
14.91 |
| 2026-08-06 00:00 |
06:51:50.91 |
-10:43:36.9 |
HIP 32848 |
15.70 |
| 2026-08-06 12:00 |
06:51:53.94 |
-10:43:56.2 |
HIP 32848 |
16.49 |
| 2026-08-07 00:00 |
06:51:56.96 |
-10:44:15.6 |
HIP 32848 |
17.29 |
| 2026-08-07 12:00 |
06:51:59.96 |
-10:44:35.3 |
HIP 32848 |
18.08 |
| 2026-08-08 00:00 |
06:52:02.95 |
-10:44:55.1 |
HIP 32848 |
18.86 |
| 2026-08-08 12:00 |
06:52:05.92 |
-10:45:15.1 |
HIP 32848 |
19.65 |
| 2026-08-09 00:00 |
06:52:08.87 |
-10:45:35.3 |
HIP 32848 |
20.44 |
| 2026-08-09 12:00 |
06:52:11.81 |
-10:45:55.7 |
HIP 32848 |
21.22 |
| 2026-08-10 00:00 |
06:52:14.72 |
-10:46:16.3 |
HIP 32848 |
22.00 |
| 2026-08-10 12:00 |
06:52:17.63 |
-10:46:37.1 |
HIP 32848 |
22.78 |
| 2026-08-11 00:00 |
06:52:20.51 |
-10:46:58.1 |
HIP 32848 |
23.55 |
| 2026-08-11 12:00 |
06:52:23.38 |
-10:47:19.2 |
HIP 32848 |
24.33 |
| 2026-08-12 00:00 |
06:52:26.23 |
-10:47:40.6 |
HIP 32848 |
25.10 |
| 2026-08-12 12:00 |
06:52:29.06 |
-10:48:02.1 |
HIP 32971 |
25.10 |
| 2026-08-13 00:00 |
06:52:31.88 |
-10:48:23.8 |
HIP 32971 |
24.95 |
| 2026-08-13 12:00 |
06:52:34.67 |
-10:48:45.7 |
HIP 32971 |
24.81 |
| 2026-08-14 00:00 |
06:52:37.45 |
-10:49:07.7 |
HIP 32971 |
24.69 |
| 2026-08-14 12:00 |
06:52:40.20 |
-10:49:30.0 |
HIP 32971 |
24.59 |
| 2026-08-15 00:00 |
06:52:42.94 |
-10:49:52.4 |
HIP 32971 |
24.51 |
| 2026-08-15 12:00 |
06:52:45.66 |
-10:50:15.0 |
HIP 32971 |
24.45 |
| 2026-08-16 00:00 |
06:52:48.36 |
-10:50:37.7 |
HIP 33075 |
24.00 |
| 2026-08-16 12:00 |
06:52:51.04 |
-10:51:00.7 |
HIP 33075 |
23.45 |
| 2026-08-17 00:00 |
06:52:53.70 |
-10:51:23.8 |
HIP 33075 |
22.90 |
| 2026-08-17 12:00 |
06:52:56.34 |
-10:51:47.0 |
HIP 33075 |
22.37 |
| 2026-08-18 00:00 |
06:52:58.96 |
-10:52:10.5 |
HIP 33075 |
21.85 |
| 2026-08-18 12:00 |
06:53:01.56 |
-10:52:34.1 |
HIP 33075 |
21.34 |
| 2026-08-19 00:00 |
06:53:04.14 |
-10:52:57.8 |
HIP 33075 |
20.84 |