C/2012 L2 (LINEAR)
| 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
$$
M_a = (11.431 + 4.832\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.431 |
| n |
4.832 |
| 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 |
| 2003-04-13 |
2012-06-17 |
-25.0962 |
+15.652 |
| 2012-06-17 |
2012-12-17 |
-1.3441 |
+0.616 |
| 2012-12-17 |
2013-05-09 |
+5.9869 |
-2.012 |
| 2013-05-09 |
2013-10-12 |
+16.3498 |
-5.750 |
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 |
18:06:50.25 |
-23:36:32.1 |
HIP 88631 |
15.56 |
| 2026-02-03 12:00 |
18:06:53.58 |
-23:36:28.4 |
HIP 88631 |
16.26 |
| 2026-02-04 00:00 |
18:06:56.88 |
-23:36:24.6 |
HIP 88631 |
16.95 |
| 2026-02-04 12:00 |
18:07:00.15 |
-23:36:20.8 |
HIP 88786 |
17.63 |
| 2026-02-05 00:00 |
18:07:03.40 |
-23:36:17.0 |
HIP 88786 |
17.31 |
| 2026-02-05 12:00 |
18:07:06.63 |
-23:36:13.2 |
HIP 88786 |
17.02 |
| 2026-02-06 00:00 |
18:07:09.82 |
-23:36:09.4 |
HIP 88786 |
16.77 |
| 2026-02-06 12:00 |
18:07:13.00 |
-23:36:05.6 |
HIP 88786 |
16.54 |
| 2026-02-07 00:00 |
18:07:16.14 |
-23:36:01.8 |
HIP 88786 |
16.34 |
| 2026-02-07 12:00 |
18:07:19.26 |
-23:35:58.0 |
HIP 88786 |
16.17 |
| 2026-02-08 00:00 |
18:07:22.35 |
-23:35:54.3 |
HIP 88786 |
16.04 |
| 2026-02-08 12:00 |
18:07:25.41 |
-23:35:50.5 |
HIP 88786 |
15.93 |
| 2026-02-09 00:00 |
18:07:28.45 |
-23:35:46.7 |
HIP 88786 |
15.86 |
| 2026-02-09 12:00 |
18:07:31.46 |
-23:35:42.9 |
HIP 88786 |
15.81 |
| 2026-02-10 00:00 |
18:07:34.44 |
-23:35:39.1 |
HIP 88786 |
15.80 |
| 2026-02-10 12:00 |
18:07:37.40 |
-23:35:35.4 |
HIP 88786 |
15.81 |
| 2026-02-11 00:00 |
18:07:40.32 |
-23:35:31.6 |
HIP 88786 |
15.86 |
| 2026-02-11 12:00 |
18:07:43.22 |
-23:35:27.8 |
HIP 88786 |
15.93 |
| 2026-02-12 00:00 |
18:07:46.08 |
-23:35:24.0 |
HIP 88786 |
16.02 |
| 2026-02-12 12:00 |
18:07:48.92 |
-23:35:20.2 |
HIP 88786 |
16.14 |
| 2026-02-13 00:00 |
18:07:51.73 |
-23:35:16.5 |
HIP 88786 |
16.28 |
| 2026-02-13 12:00 |
18:07:54.51 |
-23:35:12.7 |
HIP 88786 |
16.45 |
| 2026-02-14 00:00 |
18:07:57.26 |
-23:35:08.9 |
HIP 88786 |
16.63 |
| 2026-02-14 12:00 |
18:07:59.98 |
-23:35:05.2 |
HIP 88786 |
16.84 |
| 2026-02-15 00:00 |
18:08:02.67 |
-23:35:01.4 |
HIP 88786 |
17.06 |
| 2026-02-15 12:00 |
18:08:05.33 |
-23:34:57.7 |
HIP 88786 |
17.30 |
| 2026-02-16 00:00 |
18:08:07.96 |
-23:34:53.9 |
HIP 88786 |
17.55 |
| 2026-02-16 12:00 |
18:08:10.56 |
-23:34:50.1 |
HIP 88786 |
17.82 |
| 2026-02-17 00:00 |
18:08:13.13 |
-23:34:46.4 |
HIP 88786 |
18.09 |
| 2026-02-17 12:00 |
18:08:15.66 |
-23:34:42.7 |
HIP 88786 |
18.38 |
| 2026-02-18 00:00 |
18:08:18.17 |
-23:34:38.9 |
HIP 88786 |
18.68 |
| 2026-02-18 12:00 |
18:08:20.64 |
-23:34:35.2 |
HIP 88786 |
18.99 |
| 2026-02-19 00:00 |
18:08:23.08 |
-23:34:31.4 |
HIP 88786 |
19.30 |
| 2026-02-19 12:00 |
18:08:25.49 |
-23:34:27.7 |
HIP 88786 |
19.62 |
| 2026-02-20 00:00 |
18:08:27.87 |
-23:34:24.0 |
HIP 88995 |
19.35 |
| 2026-02-20 12:00 |
18:08:30.22 |
-23:34:20.2 |
HIP 88995 |
18.82 |
| 2026-02-21 00:00 |
18:08:32.53 |
-23:34:16.5 |
HIP 88995 |
18.30 |
| 2026-02-21 12:00 |
18:08:34.81 |
-23:34:12.8 |
HIP 88995 |
17.80 |
| 2026-02-22 00:00 |
18:08:37.06 |
-23:34:09.1 |
HIP 88995 |
17.30 |
| 2026-02-22 12:00 |
18:08:39.27 |
-23:34:05.4 |
HIP 88995 |
16.81 |
| 2026-02-23 00:00 |
18:08:41.45 |
-23:34:01.7 |
HIP 88995 |
16.32 |
| 2026-02-23 12:00 |
18:08:43.60 |
-23:33:58.0 |
HIP 88995 |
15.85 |
| 2026-02-24 00:00 |
18:08:45.71 |
-23:33:54.3 |
HIP 88995 |
15.39 |