| Parameter |
Value |
| Designation |
C/2023 S3 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2024-01-19T14:58:00.491520Z |
| Orbit solution date (soln_date, UTC) |
2024-08-02T01:42:20Z |
| Obs used |
692 |
| NEO |
Yes |
| M1 |
16.300 |
| K1 |
9.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2023-09-25T10:53:32.726400Z |
| Discovery magnitude (MPC) |
19.99 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-12-22.0000000 |
| e |
0.97084030 |
| q (au) |
0.830157 |
| a (au) |
28.469320 |
| i (deg) |
140.498019 |
| Ω (om, deg) |
233.833529 |
| ω (w, deg) |
281.571309 |
| M (ma, deg) |
359.814278 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.227 + 4.398\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.227 |
| n |
4.398 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.998 |
| 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 |
| 2023-09-25 |
2023-11-18 |
-4.1066 |
+1.202 |
| 2023-11-18 |
2024-01-09 |
+21.3814 |
-2.097 |
| 2024-02-11 |
2024-03-09 |
+21.5517 |
-3.253 |
| 2024-03-09 |
2024-06-02 |
+1.1889 |
-1.105 |
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 |
12:06:02.48 |
+36:51:07.3 |
HIP 59117 |
18.62 |
| 2026-07-29 12:00 |
12:06:09.10 |
+36:49:24.2 |
HIP 59117 |
18.53 |
| 2026-07-30 00:00 |
12:06:15.80 |
+36:47:41.5 |
HIP 59117 |
18.67 |
| 2026-07-30 12:00 |
12:06:22.57 |
+36:45:59.0 |
HIP 59117 |
19.04 |
| 2026-07-31 00:00 |
12:06:29.43 |
+36:44:16.8 |
HIP 59117 |
19.65 |
| 2026-07-31 12:00 |
12:06:36.36 |
+36:42:34.8 |
HIP 59117 |
20.45 |
| 2026-08-01 00:00 |
12:06:43.36 |
+36:40:53.2 |
HIP 59117 |
21.44 |
| 2026-08-01 12:00 |
12:06:50.44 |
+36:39:11.8 |
HIP 59117 |
22.59 |
| 2026-08-02 00:00 |
12:06:57.60 |
+36:37:30.7 |
HIP 59117 |
23.89 |
| 2026-08-02 12:00 |
12:07:04.83 |
+36:35:49.9 |
HIP 59117 |
25.30 |
| 2026-08-03 00:00 |
12:07:12.13 |
+36:34:09.5 |
HIP 59117 |
26.82 |
| 2026-08-03 12:00 |
12:07:19.50 |
+36:32:29.3 |
HIP 59117 |
28.42 |
| 2026-08-04 00:00 |
12:07:26.95 |
+36:30:49.5 |
HIP 59117 |
30.10 |
| 2026-08-04 12:00 |
12:07:34.47 |
+36:29:09.9 |
HIP 59117 |
31.84 |
| 2026-08-05 00:00 |
12:07:42.05 |
+36:27:30.7 |
HIP 59117 |
33.64 |
| 2026-08-05 12:00 |
12:07:49.71 |
+36:25:51.8 |
HIP 59117 |
35.49 |
| 2026-08-06 00:00 |
12:07:57.44 |
+36:24:13.3 |
HIP 59117 |
37.37 |
| 2026-08-06 12:00 |
12:08:05.24 |
+36:22:35.1 |
HIP 59117 |
39.30 |
| 2026-08-07 00:00 |
12:08:13.10 |
+36:20:57.2 |
HIP 59252 |
40.29 |
| 2026-08-07 12:00 |
12:08:21.03 |
+36:19:19.7 |
HIP 59252 |
38.25 |
| 2026-08-08 00:00 |
12:08:29.03 |
+36:17:42.5 |
HIP 59252 |
36.25 |
| 2026-08-08 12:00 |
12:08:37.09 |
+36:16:05.7 |
HIP 59252 |
34.29 |
| 2026-08-09 00:00 |
12:08:45.22 |
+36:14:29.3 |
HIP 59252 |
32.37 |
| 2026-08-09 12:00 |
12:08:53.42 |
+36:12:53.2 |
HIP 59252 |
30.51 |
| 2026-08-10 00:00 |
12:09:01.68 |
+36:11:17.6 |
HIP 59252 |
28.72 |
| 2026-08-10 12:00 |
12:09:10.00 |
+36:09:42.3 |
HIP 59252 |
27.01 |
| 2026-08-11 00:00 |
12:09:18.38 |
+36:08:07.4 |
HIP 59252 |
25.41 |
| 2026-08-11 12:00 |
12:09:26.83 |
+36:06:32.8 |
HIP 59252 |
23.94 |
| 2026-08-12 00:00 |
12:09:35.34 |
+36:04:58.7 |
HIP 59252 |
22.61 |
| 2026-08-12 12:00 |
12:09:43.91 |
+36:03:25.0 |
HIP 59252 |
21.47 |
| 2026-08-13 00:00 |
12:09:52.54 |
+36:01:51.7 |
HIP 59252 |
20.54 |
| 2026-08-13 12:00 |
12:10:01.22 |
+36:00:18.8 |
HIP 59444 |
19.35 |
| 2026-08-14 00:00 |
12:10:09.97 |
+35:58:46.4 |
HIP 59444 |
18.15 |
| 2026-08-14 12:00 |
12:10:18.77 |
+35:57:14.4 |
HIP 59444 |
17.18 |
| 2026-08-15 00:00 |
12:10:27.63 |
+35:55:42.8 |
HIP 59444 |
16.47 |
| 2026-08-15 12:00 |
12:10:36.55 |
+35:54:11.6 |
HIP 59444 |
16.06 |
| 2026-08-16 00:00 |
12:10:45.52 |
+35:52:40.9 |
HIP 59444 |
15.98 |
| 2026-08-16 12:00 |
12:10:54.55 |
+35:51:10.7 |
HIP 59444 |
16.24 |
| 2026-08-17 00:00 |
12:11:03.63 |
+35:49:40.9 |
HIP 59444 |
16.81 |
| 2026-08-17 12:00 |
12:11:12.77 |
+35:48:11.5 |
HIP 59540 |
16.65 |
| 2026-08-18 00:00 |
12:11:21.95 |
+35:46:42.6 |
HIP 59540 |
14.65 |
| 2026-08-18 12:00 |
12:11:31.19 |
+35:45:14.2 |
HIP 59540 |
12.75 |
| 2026-08-19 00:00 |
12:11:40.48 |
+35:43:46.3 |
HIP 59540 |
11.04 |