| Parameter |
Value |
| Designation |
C/2012 L2 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-05-09T08:04:55.027200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:14Z |
| Obs used |
2119 |
| NEO |
- |
| M1 |
11.300 |
| K1 |
6.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-12-18.0000000 |
| e |
0.99733350 |
| q (au) |
1.508545 |
| a (au) |
565.739557 |
| i (deg) |
70.980594 |
| Ω (om, deg) |
270.302116 |
| ω (w, deg) |
205.786395 |
| M (ma, deg) |
359.989575 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.171 + 4.614\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.171 |
| n |
4.614 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.874 |
| 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 |
| 2003-04-13 |
2012-06-17 |
-24.5614 |
+15.420 |
| 2012-06-17 |
2012-12-17 |
-0.8759 |
+0.427 |
| 2012-12-17 |
2013-05-09 |
+6.2793 |
-2.140 |
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 |
18:06:59.03 |
-23:25:38.5 |
HIP 88786 |
8.78 |
| 2026-05-12 12:00 |
18:06:55.73 |
-23:25:35.6 |
HIP 88786 |
9.34 |
| 2026-05-13 00:00 |
18:06:52.41 |
-23:25:32.7 |
HIP 88786 |
9.93 |
| 2026-05-13 12:00 |
18:06:49.07 |
-23:25:29.7 |
HIP 88786 |
10.54 |
| 2026-05-14 00:00 |
18:06:45.70 |
-23:25:26.8 |
HIP 88786 |
11.18 |
| 2026-05-14 12:00 |
18:06:42.31 |
-23:25:23.9 |
HIP 88786 |
11.84 |
| 2026-05-15 00:00 |
18:06:38.89 |
-23:25:21.0 |
HIP 88786 |
12.52 |
| 2026-05-15 12:00 |
18:06:35.45 |
-23:25:18.1 |
HIP 88631 |
12.56 |
| 2026-05-16 00:00 |
18:06:31.99 |
-23:25:15.2 |
HIP 88631 |
11.88 |
| 2026-05-16 12:00 |
18:06:28.50 |
-23:25:12.3 |
HIP 88631 |
11.21 |
| 2026-05-17 00:00 |
18:06:24.98 |
-23:25:09.3 |
HIP 88631 |
10.56 |
| 2026-05-17 12:00 |
18:06:21.45 |
-23:25:06.4 |
HIP 88631 |
9.93 |
| 2026-05-18 00:00 |
18:06:17.89 |
-23:25:03.5 |
HIP 88631 |
9.32 |
| 2026-05-18 12:00 |
18:06:14.31 |
-23:25:00.6 |
HIP 88631 |
8.74 |
| 2026-05-19 00:00 |
18:06:10.71 |
-23:24:57.6 |
HIP 88631 |
8.19 |
| 2026-05-19 12:00 |
18:06:07.09 |
-23:24:54.7 |
HIP 88631 |
7.70 |
| 2026-05-20 00:00 |
18:06:03.44 |
-23:24:51.8 |
HIP 88631 |
7.26 |
| 2026-05-20 12:00 |
18:05:59.78 |
-23:24:48.8 |
HIP 88631 |
6.90 |
| 2026-05-21 00:00 |
18:05:56.09 |
-23:24:45.9 |
HIP 88631 |
6.63 |
| 2026-05-21 12:00 |
18:05:52.38 |
-23:24:43.0 |
HIP 88631 |
6.45 |
| 2026-05-22 00:00 |
18:05:48.66 |
-23:24:40.0 |
HIP 88631 |
6.38 |
| 2026-05-22 12:00 |
18:05:44.91 |
-23:24:37.1 |
HIP 88631 |
6.43 |
| 2026-05-23 00:00 |
18:05:41.14 |
-23:24:34.1 |
HIP 88631 |
6.59 |
| 2026-05-23 12:00 |
18:05:37.36 |
-23:24:31.2 |
HIP 88631 |
6.86 |
| 2026-05-24 00:00 |
18:05:33.56 |
-23:24:28.2 |
HIP 88631 |
7.22 |
| 2026-05-24 12:00 |
18:05:29.73 |
-23:24:25.3 |
HIP 88631 |
7.67 |
| 2026-05-25 00:00 |
18:05:25.89 |
-23:24:22.3 |
HIP 88631 |
8.20 |
| 2026-05-25 12:00 |
18:05:22.03 |
-23:24:19.3 |
HIP 88631 |
8.78 |
| 2026-05-26 00:00 |
18:05:18.16 |
-23:24:16.4 |
HIP 88631 |
9.41 |
| 2026-05-26 12:00 |
18:05:14.26 |
-23:24:13.4 |
HIP 88631 |
10.09 |
| 2026-05-27 00:00 |
18:05:10.35 |
-23:24:10.4 |
HIP 88631 |
10.80 |
| 2026-05-27 12:00 |
18:05:06.43 |
-23:24:07.4 |
HIP 88631 |
11.54 |
| 2026-05-28 00:00 |
18:05:02.48 |
-23:24:04.4 |
HIP 88631 |
12.30 |
| 2026-05-28 12:00 |
18:04:58.53 |
-23:24:01.4 |
HIP 88631 |
13.09 |
| 2026-05-29 00:00 |
18:04:54.55 |
-23:23:58.4 |
HIP 88631 |
13.89 |
| 2026-05-29 12:00 |
18:04:50.56 |
-23:23:55.4 |
HIP 88631 |
14.71 |
| 2026-05-30 00:00 |
18:04:46.55 |
-23:23:52.4 |
HIP 88631 |
15.54 |
| 2026-05-30 12:00 |
18:04:42.53 |
-23:23:49.4 |
HIP 88631 |
16.39 |
| 2026-05-31 00:00 |
18:04:38.50 |
-23:23:46.4 |
HIP 88631 |
17.25 |
| 2026-05-31 12:00 |
18:04:34.45 |
-23:23:43.4 |
HIP 88631 |
18.11 |
| 2026-06-01 00:00 |
18:04:30.39 |
-23:23:40.3 |
HIP 88631 |
18.99 |
| 2026-06-01 12:00 |
18:04:26.31 |
-23:23:37.3 |
HIP 88631 |
19.87 |
| 2026-06-02 00:00 |
18:04:22.22 |
-23:23:34.3 |
HIP 88631 |
20.77 |