| Parameter |
Value |
| Designation |
C/2009 S3 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2011-12-11T06:01:00.886080Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:34Z |
| Obs used |
278 |
| NEO |
- |
| M1 |
11.700 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-11-26.0000000 |
| e |
1.00141917 |
| q (au) |
6.474515 |
| a (au) |
-4562.197370 |
| i (deg) |
60.384601 |
| Ω (om, deg) |
225.132530 |
| ω (w, deg) |
129.760860 |
| M (ma, deg) |
-0.000049 |
Magnitude
Scatter + Global Linear
$$
M_a = (3.843 + 4.920\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
3.843 |
| n |
4.920 |
| gf |
0.872 |
| gb |
-0.998 |
| k |
1.000 |
| δ90 |
7.536 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
06:29:41.68 |
-31:31:04.3 |
HIP 30967 |
21.00 |
| 2026-06-01 12:00 |
06:29:46.43 |
-31:30:48.3 |
HIP 30967 |
20.56 |
| 2026-06-02 00:00 |
06:29:51.19 |
-31:30:32.6 |
HIP 30967 |
20.17 |
| 2026-06-02 12:00 |
06:29:55.98 |
-31:30:17.3 |
HIP 30967 |
19.84 |
| 2026-06-03 00:00 |
06:30:00.78 |
-31:30:02.3 |
HIP 30967 |
19.57 |
| 2026-06-03 12:00 |
06:30:05.59 |
-31:29:47.8 |
HIP 30967 |
19.36 |
| 2026-06-04 00:00 |
06:30:10.42 |
-31:29:33.6 |
HIP 30967 |
19.21 |
| 2026-06-04 12:00 |
06:30:15.26 |
-31:29:19.8 |
HIP 30967 |
19.12 |
| 2026-06-05 00:00 |
06:30:20.12 |
-31:29:06.4 |
HIP 30967 |
19.10 |
| 2026-06-05 12:00 |
06:30:24.99 |
-31:28:53.4 |
HIP 30967 |
19.14 |
| 2026-06-06 00:00 |
06:30:29.87 |
-31:28:40.7 |
HIP 30967 |
19.25 |
| 2026-06-06 12:00 |
06:30:34.77 |
-31:28:28.5 |
HIP 30967 |
19.43 |
| 2026-06-07 00:00 |
06:30:39.68 |
-31:28:16.6 |
HIP 30967 |
19.66 |
| 2026-06-07 12:00 |
06:30:44.60 |
-31:28:05.1 |
HIP 30967 |
19.96 |
| 2026-06-08 00:00 |
06:30:49.54 |
-31:27:54.0 |
HIP 31135 |
19.38 |
| 2026-06-08 12:00 |
06:30:54.49 |
-31:27:43.3 |
HIP 31135 |
18.48 |
| 2026-06-09 00:00 |
06:30:59.45 |
-31:27:33.0 |
HIP 31135 |
17.61 |
| 2026-06-09 12:00 |
06:31:04.42 |
-31:27:23.0 |
HIP 31135 |
16.76 |
| 2026-06-10 00:00 |
06:31:09.40 |
-31:27:13.5 |
HIP 31135 |
15.94 |
| 2026-06-10 12:00 |
06:31:14.40 |
-31:27:04.4 |
HIP 31135 |
15.15 |
| 2026-06-11 00:00 |
06:31:19.40 |
-31:26:55.6 |
HIP 31135 |
14.41 |
| 2026-06-11 12:00 |
06:31:24.42 |
-31:26:47.2 |
HIP 31135 |
13.72 |
| 2026-06-12 00:00 |
06:31:29.45 |
-31:26:39.3 |
HIP 31135 |
13.08 |
| 2026-06-12 12:00 |
06:31:34.48 |
-31:26:31.7 |
HIP 31135 |
12.51 |
| 2026-06-13 00:00 |
06:31:39.53 |
-31:26:24.6 |
HIP 31135 |
12.02 |
| 2026-06-13 12:00 |
06:31:44.59 |
-31:26:17.8 |
HIP 31135 |
11.62 |
| 2026-06-14 00:00 |
06:31:49.65 |
-31:26:11.4 |
HIP 31135 |
11.31 |
| 2026-06-14 12:00 |
06:31:54.73 |
-31:26:05.4 |
HIP 31135 |
11.10 |
| 2026-06-15 00:00 |
06:31:59.81 |
-31:25:59.9 |
HIP 31135 |
11.01 |
| 2026-06-15 12:00 |
06:32:04.90 |
-31:25:54.7 |
HIP 31135 |
11.03 |
| 2026-06-16 00:00 |
06:32:10.00 |
-31:25:49.9 |
HIP 31135 |
11.17 |
| 2026-06-16 12:00 |
06:32:15.10 |
-31:25:45.6 |
HIP 31135 |
11.41 |
| 2026-06-17 00:00 |
06:32:20.22 |
-31:25:41.6 |
HIP 31135 |
11.76 |
| 2026-06-17 12:00 |
06:32:25.34 |
-31:25:38.0 |
HIP 31135 |
12.20 |
| 2026-06-18 00:00 |
06:32:30.47 |
-31:25:34.9 |
HIP 31135 |
12.73 |
| 2026-06-18 12:00 |
06:32:35.60 |
-31:25:32.1 |
HIP 31135 |
13.34 |
| 2026-06-19 00:00 |
06:32:40.74 |
-31:25:29.8 |
HIP 31135 |
14.01 |
| 2026-06-19 12:00 |
06:32:45.88 |
-31:25:27.8 |
HIP 31135 |
14.73 |
| 2026-06-20 00:00 |
06:32:51.03 |
-31:25:26.2 |
HIP 31135 |
15.51 |
| 2026-06-20 12:00 |
06:32:56.19 |
-31:25:25.1 |
HIP 31135 |
16.33 |
| 2026-06-21 00:00 |
06:33:01.35 |
-31:25:24.4 |
HIP 31135 |
17.18 |
| 2026-06-21 12:00 |
06:33:06.51 |
-31:25:24.0 |
HIP 31135 |
18.07 |
| 2026-06-22 00:00 |
06:33:11.68 |
-31:25:24.1 |
HIP 31135 |
18.98 |