| Parameter |
Value |
| Designation |
C/2012 F6 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-03-24T12:20:06.757440Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:07Z |
| Obs used |
3201 |
| NEO |
- |
| M1 |
5.600 |
| K1 |
14.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-07-29.0000000 |
| e |
0.99849892 |
| q (au) |
0.731238 |
| a (au) |
487.140054 |
| i (deg) |
82.608873 |
| Ω (om, deg) |
332.715296 |
| ω (w, deg) |
304.986917 |
| M (ma, deg) |
0.011595 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.992 + 5.601\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.992 |
| n |
5.601 |
| gf |
0.993 |
| gb |
-0.972 |
| k |
0.966 |
| δ90 |
9.940 |
| 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 |
| 2012-01-22 |
2013-01-26 |
+10.6292 |
-3.477 |
| 2013-01-26 |
2013-02-05 |
-5.2552 |
-0.788 |
| 2013-02-05 |
2013-03-14 |
+0.6982 |
-1.791 |
| 2013-04-01 |
2013-06-19 |
+4.0499 |
-1.366 |
| 2013-06-19 |
2013-07-13 |
-5.5480 |
+1.307 |
| 2013-07-13 |
2013-08-08 |
-11.8322 |
+3.586 |
| 2013-08-08 |
2014-10-27 |
+0.7307 |
-0.852 |
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 |
14:15:19.15 |
+76:56:17.8 |
HIP 69852 |
11.83 |
| 2026-05-12 12:00 |
14:15:03.00 |
+76:56:01.8 |
HIP 69852 |
12.31 |
| 2026-05-13 00:00 |
14:14:46.90 |
+76:55:45.3 |
HIP 69852 |
12.83 |
| 2026-05-13 12:00 |
14:14:30.85 |
+76:55:28.3 |
HIP 69852 |
13.39 |
| 2026-05-14 00:00 |
14:14:14.86 |
+76:55:10.7 |
HIP 69852 |
13.99 |
| 2026-05-14 12:00 |
14:13:58.93 |
+76:54:52.6 |
HIP 69852 |
14.62 |
| 2026-05-15 00:00 |
14:13:43.05 |
+76:54:34.0 |
HIP 69852 |
15.28 |
| 2026-05-15 12:00 |
14:13:27.23 |
+76:54:14.9 |
HIP 69852 |
15.96 |
| 2026-05-16 00:00 |
14:13:11.48 |
+76:53:55.2 |
HIP 69852 |
16.67 |
| 2026-05-16 12:00 |
14:12:55.78 |
+76:53:35.0 |
HIP 69852 |
17.39 |
| 2026-05-17 00:00 |
14:12:40.15 |
+76:53:14.4 |
HIP 69852 |
18.12 |
| 2026-05-17 12:00 |
14:12:24.59 |
+76:52:53.2 |
HIP 69852 |
18.88 |
| 2026-05-18 00:00 |
14:12:09.10 |
+76:52:31.4 |
HIP 69852 |
19.64 |
| 2026-05-18 12:00 |
14:11:53.67 |
+76:52:09.2 |
HIP 69852 |
20.42 |
| 2026-05-19 00:00 |
14:11:38.31 |
+76:51:46.5 |
HIP 69852 |
21.20 |
| 2026-05-19 12:00 |
14:11:23.03 |
+76:51:23.2 |
HIP 68816 |
21.77 |
| 2026-05-20 00:00 |
14:11:07.82 |
+76:50:59.5 |
HIP 68816 |
21.11 |
| 2026-05-20 12:00 |
14:10:52.68 |
+76:50:35.3 |
HIP 68816 |
20.49 |
| 2026-05-21 00:00 |
14:10:37.62 |
+76:50:10.6 |
HIP 68816 |
19.89 |
| 2026-05-21 12:00 |
14:10:22.64 |
+76:49:45.3 |
HIP 68816 |
19.33 |
| 2026-05-22 00:00 |
14:10:07.74 |
+76:49:19.6 |
HIP 68816 |
18.81 |
| 2026-05-22 12:00 |
14:09:52.91 |
+76:48:53.4 |
HIP 68816 |
18.33 |
| 2026-05-23 00:00 |
14:09:38.17 |
+76:48:26.8 |
HIP 68816 |
17.90 |
| 2026-05-23 12:00 |
14:09:23.51 |
+76:47:59.6 |
HIP 68816 |
17.51 |
| 2026-05-24 00:00 |
14:09:08.93 |
+76:47:32.0 |
HIP 68816 |
17.17 |
| 2026-05-24 12:00 |
14:08:54.44 |
+76:47:03.9 |
HIP 68816 |
16.89 |
| 2026-05-25 00:00 |
14:08:40.03 |
+76:46:35.3 |
HIP 68816 |
16.67 |
| 2026-05-25 12:00 |
14:08:25.71 |
+76:46:06.3 |
HIP 68816 |
16.51 |
| 2026-05-26 00:00 |
14:08:11.47 |
+76:45:36.8 |
HIP 68816 |
16.41 |
| 2026-05-26 12:00 |
14:07:57.33 |
+76:45:06.9 |
HIP 68816 |
16.37 |
| 2026-05-27 00:00 |
14:07:43.28 |
+76:44:36.5 |
HIP 68816 |
16.39 |
| 2026-05-27 12:00 |
14:07:29.31 |
+76:44:05.6 |
HIP 68816 |
16.48 |
| 2026-05-28 00:00 |
14:07:15.44 |
+76:43:34.3 |
HIP 68816 |
16.63 |
| 2026-05-28 12:00 |
14:07:01.67 |
+76:43:02.5 |
HIP 68816 |
16.84 |
| 2026-05-29 00:00 |
14:06:47.98 |
+76:42:30.3 |
HIP 68816 |
17.11 |
| 2026-05-29 12:00 |
14:06:34.39 |
+76:41:57.7 |
HIP 68816 |
17.43 |
| 2026-05-30 00:00 |
14:06:20.90 |
+76:41:24.6 |
HIP 68816 |
17.81 |
| 2026-05-30 12:00 |
14:06:07.51 |
+76:40:51.1 |
HIP 68816 |
18.23 |
| 2026-05-31 00:00 |
14:05:54.21 |
+76:40:17.2 |
HIP 68816 |
18.70 |
| 2026-05-31 12:00 |
14:05:41.01 |
+76:39:42.8 |
HIP 68816 |
19.21 |
| 2026-06-01 00:00 |
14:05:27.91 |
+76:39:08.0 |
HIP 68816 |
19.77 |
| 2026-06-01 12:00 |
14:05:14.91 |
+76:38:32.8 |
HIP 68816 |
20.35 |
| 2026-06-02 00:00 |
14:05:02.02 |
+76:37:57.2 |
HIP 68816 |
20.97 |