| Parameter |
Value |
| Designation |
C/2023 V1 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2025-07-13T00:46:00.704640Z |
| Orbit solution date (soln_date, UTC) |
2026-07-06T12:12:23Z |
| Obs used |
468 |
| NEO |
- |
| M1 |
6.700 |
| K1 |
11.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2023-11-02T05:36:33.494400Z |
| Discovery magnitude (MPC) |
20.39 G |
| Discovery observatory (MPC) |
I52 · Steward Observatory, Mt. Lemmon Station |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2025-04-06.0000000 |
| e |
1.00033960 |
| q (au) |
5.092600 |
| a (au) |
-14996.073952 |
| i (deg) |
102.014031 |
| Ω (om, deg) |
15.039970 |
| ω (w, deg) |
103.313076 |
| M (ma, deg) |
-0.000053 |
Magnitude
Scatter + Global Linear
$$
M_a = (3.946 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
3.946 |
| n |
6.000 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.996 |
| δ90 |
1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
13:37:36.20 |
+24:39:19.1 |
HIP 66417 |
8.80 |
| 2026-07-29 12:00 |
13:37:33.85 |
+24:34:10.0 |
HIP 66417 |
8.33 |
| 2026-07-30 00:00 |
13:37:31.68 |
+24:29:01.4 |
HIP 66417 |
10.74 |
| 2026-07-30 12:00 |
13:37:29.67 |
+24:23:53.1 |
HIP 66417 |
14.67 |
| 2026-07-31 00:00 |
13:37:27.83 |
+24:18:45.2 |
HIP 66417 |
19.19 |
| 2026-07-31 12:00 |
13:37:26.16 |
+24:13:37.8 |
HIP 66579 |
19.88 |
| 2026-08-01 00:00 |
13:37:24.65 |
+24:08:30.8 |
HIP 66585 |
21.10 |
| 2026-08-01 12:00 |
13:37:23.31 |
+24:03:24.2 |
HIP 66357 |
19.11 |
| 2026-08-02 00:00 |
13:37:22.13 |
+23:58:18.0 |
HIP 66357 |
17.51 |
| 2026-08-02 12:00 |
13:37:21.11 |
+23:53:12.3 |
HIP 66357 |
17.37 |
| 2026-08-03 00:00 |
13:37:20.25 |
+23:48:07.1 |
HIP 66357 |
18.71 |
| 2026-08-03 12:00 |
13:37:19.56 |
+23:43:02.3 |
HIP 66533 |
16.06 |
| 2026-08-04 00:00 |
13:37:19.02 |
+23:37:58.0 |
HIP 66533 |
14.16 |
| 2026-08-04 12:00 |
13:37:18.64 |
+23:32:54.1 |
HIP 66533 |
13.90 |
| 2026-08-05 00:00 |
13:37:18.41 |
+23:27:50.7 |
HIP 66533 |
15.38 |
| 2026-08-05 12:00 |
13:37:18.34 |
+23:22:47.8 |
HIP 66533 |
18.15 |
| 2026-08-06 00:00 |
13:37:18.42 |
+23:17:45.4 |
HIP 66533 |
21.73 |
| 2026-08-06 12:00 |
13:37:18.66 |
+23:12:43.5 |
HIP 66533 |
25.78 |
| 2026-08-07 00:00 |
13:37:19.05 |
+23:07:42.1 |
HIP 66396 |
23.29 |
| 2026-08-07 12:00 |
13:37:19.58 |
+23:02:41.2 |
HIP 66396 |
18.63 |
| 2026-08-08 00:00 |
13:37:20.27 |
+22:57:40.8 |
HIP 66396 |
14.25 |
| 2026-08-08 12:00 |
13:37:21.10 |
+22:52:41.0 |
HIP 66396 |
10.48 |
| 2026-08-09 00:00 |
13:37:22.08 |
+22:47:41.6 |
HIP 66396 |
8.20 |
| 2026-08-09 12:00 |
13:37:23.21 |
+22:42:42.8 |
HIP 66395 |
8.66 |
| 2026-08-10 00:00 |
13:37:24.48 |
+22:37:44.6 |
HIP 66511 |
10.40 |
| 2026-08-10 12:00 |
13:37:25.89 |
+22:32:46.9 |
HIP 66511 |
8.19 |
| 2026-08-11 00:00 |
13:37:27.45 |
+22:27:49.7 |
HIP 66511 |
8.64 |
| 2026-08-11 12:00 |
13:37:29.15 |
+22:22:53.1 |
HIP 66511 |
11.45 |
| 2026-08-12 00:00 |
13:37:30.98 |
+22:17:57.1 |
HIP 66511 |
15.36 |
| 2026-08-12 12:00 |
13:37:32.96 |
+22:13:01.7 |
HIP 66511 |
19.72 |
| 2026-08-13 00:00 |
13:37:35.07 |
+22:08:06.8 |
HIP 66375 |
20.29 |
| 2026-08-13 12:00 |
13:37:37.32 |
+22:03:12.5 |
HIP 66375 |
18.21 |
| 2026-08-14 00:00 |
13:37:39.70 |
+21:58:18.8 |
HIP 66375 |
17.35 |
| 2026-08-14 12:00 |
13:37:42.21 |
+21:53:25.8 |
HIP 66375 |
17.89 |
| 2026-08-15 00:00 |
13:37:44.86 |
+21:48:33.3 |
HIP 66375 |
19.71 |
| 2026-08-15 12:00 |
13:37:47.64 |
+21:43:41.4 |
HIP 66595 |
18.27 |
| 2026-08-16 00:00 |
13:37:50.54 |
+21:38:50.2 |
HIP 66595 |
16.80 |
| 2026-08-16 12:00 |
13:37:53.58 |
+21:33:59.6 |
HIP 66595 |
16.67 |
| 2026-08-17 00:00 |
13:37:56.74 |
+21:29:09.6 |
HIP 66595 |
17.90 |
| 2026-08-17 12:00 |
13:38:00.03 |
+21:24:20.2 |
HIP 66595 |
20.23 |
| 2026-08-18 00:00 |
13:38:03.44 |
+21:19:31.5 |
HIP 66595 |
23.34 |
| 2026-08-18 12:00 |
13:38:06.97 |
+21:14:43.4 |
HIP 66595 |
26.96 |
| 2026-08-19 00:00 |
13:38:10.63 |
+21:09:56.0 |
HIP 66670 |
28.40 |