| Parameter |
Value |
| Designation |
C/2013 G6 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2013-07-25T05:28:45.828480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:34Z |
| Obs used |
230 |
| NEO |
- |
| M1 |
7.100 |
| K1 |
27.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-06-18.0000000 |
| e |
0.99470498 |
| q (au) |
2.048499 |
| a (au) |
386.872597 |
| i (deg) |
124.084326 |
| Ω (om, deg) |
44.567402 |
| ω (w, deg) |
215.692475 |
| M (ma, deg) |
359.995178 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.905 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.905 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.985 |
| k |
1.000 |
| 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 |
| 2013-04-13 |
2013-07-08 |
+39.8450 |
-14.076 |
| 2013-08-03 |
2014-02-05 |
+22.5987 |
-10.710 |
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 |
02:38:36.99 |
+20:09:59.1 |
HIP 12266 |
11.96 |
| 2026-07-29 12:00 |
02:38:37.14 |
+20:10:08.3 |
HIP 12266 |
12.08 |
| 2026-07-30 00:00 |
02:38:37.25 |
+20:10:17.5 |
HIP 12266 |
12.19 |
| 2026-07-30 12:00 |
02:38:37.33 |
+20:10:26.5 |
HIP 12266 |
12.29 |
| 2026-07-31 00:00 |
02:38:37.37 |
+20:10:35.3 |
HIP 12266 |
12.39 |
| 2026-07-31 12:00 |
02:38:37.38 |
+20:10:44.0 |
HIP 12266 |
12.48 |
| 2026-08-01 00:00 |
02:38:37.35 |
+20:10:52.6 |
HIP 12266 |
12.56 |
| 2026-08-01 12:00 |
02:38:37.29 |
+20:11:01.0 |
HIP 12266 |
12.63 |
| 2026-08-02 00:00 |
02:38:37.20 |
+20:11:09.2 |
HIP 12266 |
12.70 |
| 2026-08-02 12:00 |
02:38:37.07 |
+20:11:17.3 |
HIP 12266 |
12.77 |
| 2026-08-03 00:00 |
02:38:36.91 |
+20:11:25.3 |
HIP 12266 |
12.82 |
| 2026-08-03 12:00 |
02:38:36.71 |
+20:11:33.1 |
HIP 12266 |
12.87 |
| 2026-08-04 00:00 |
02:38:36.48 |
+20:11:40.7 |
HIP 12266 |
12.91 |
| 2026-08-04 12:00 |
02:38:36.22 |
+20:11:48.2 |
HIP 12266 |
12.95 |
| 2026-08-05 00:00 |
02:38:35.92 |
+20:11:55.6 |
HIP 12266 |
12.98 |
| 2026-08-05 12:00 |
02:38:35.58 |
+20:12:02.8 |
HIP 12266 |
13.00 |
| 2026-08-06 00:00 |
02:38:35.21 |
+20:12:09.8 |
HIP 12266 |
13.02 |
| 2026-08-06 12:00 |
02:38:34.80 |
+20:12:16.7 |
HIP 12266 |
13.03 |
| 2026-08-07 00:00 |
02:38:34.37 |
+20:12:23.4 |
HIP 12266 |
13.04 |
| 2026-08-07 12:00 |
02:38:33.89 |
+20:12:30.0 |
HIP 12266 |
13.04 |
| 2026-08-08 00:00 |
02:38:33.38 |
+20:12:36.4 |
HIP 12266 |
13.03 |
| 2026-08-08 12:00 |
02:38:32.84 |
+20:12:42.7 |
HIP 12266 |
13.02 |
| 2026-08-09 00:00 |
02:38:32.26 |
+20:12:48.8 |
HIP 12266 |
13.00 |
| 2026-08-09 12:00 |
02:38:31.64 |
+20:12:54.7 |
HIP 12266 |
12.98 |
| 2026-08-10 00:00 |
02:38:30.99 |
+20:13:00.5 |
HIP 12266 |
12.95 |
| 2026-08-10 12:00 |
02:38:30.31 |
+20:13:06.2 |
HIP 12266 |
12.92 |
| 2026-08-11 00:00 |
02:38:29.59 |
+20:13:11.6 |
HIP 12266 |
12.89 |
| 2026-08-11 12:00 |
02:38:28.83 |
+20:13:17.0 |
HIP 12266 |
12.84 |
| 2026-08-12 00:00 |
02:38:28.04 |
+20:13:22.1 |
HIP 12266 |
12.80 |
| 2026-08-12 12:00 |
02:38:27.22 |
+20:13:27.1 |
HIP 12266 |
12.75 |
| 2026-08-13 00:00 |
02:38:26.36 |
+20:13:31.9 |
HIP 12266 |
12.70 |
| 2026-08-13 12:00 |
02:38:25.46 |
+20:13:36.6 |
HIP 12266 |
12.64 |
| 2026-08-14 00:00 |
02:38:24.53 |
+20:13:41.1 |
HIP 12266 |
12.58 |
| 2026-08-14 12:00 |
02:38:23.57 |
+20:13:45.5 |
HIP 12266 |
12.52 |
| 2026-08-15 00:00 |
02:38:22.56 |
+20:13:49.7 |
HIP 12266 |
12.46 |
| 2026-08-15 12:00 |
02:38:21.53 |
+20:13:53.7 |
HIP 12266 |
12.39 |
| 2026-08-16 00:00 |
02:38:20.46 |
+20:13:57.6 |
HIP 12266 |
12.33 |
| 2026-08-16 12:00 |
02:38:19.35 |
+20:14:01.3 |
HIP 12266 |
12.26 |
| 2026-08-17 00:00 |
02:38:18.21 |
+20:14:04.8 |
HIP 12266 |
12.19 |
| 2026-08-17 12:00 |
02:38:17.04 |
+20:14:08.2 |
HIP 12266 |
12.12 |
| 2026-08-18 00:00 |
02:38:15.83 |
+20:14:11.4 |
HIP 12266 |
12.05 |
| 2026-08-18 12:00 |
02:38:14.58 |
+20:14:14.4 |
HIP 12266 |
11.98 |
| 2026-08-19 00:00 |
02:38:13.30 |
+20:14:17.3 |
HIP 12266 |
11.92 |