| Parameter |
Value |
| Designation |
C/2022 Y2 (Lemmon) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-03-22T15:21:30.427200Z |
| Orbit solution date (soln_date, UTC) |
2023-10-13T18:13:03Z |
| Obs used |
164 |
| NEO |
- |
| M1 |
9.700 |
| K1 |
20.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2022-12-24T11:14:57.408000Z |
| Discovery magnitude (MPC) |
20.08 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-02-01.0000000 |
| e |
0.87043280 |
| q (au) |
2.544961 |
| a (au) |
19.642019 |
| i (deg) |
165.907028 |
| Ω (om, deg) |
216.349394 |
| ω (w, deg) |
105.553752 |
| M (ma, deg) |
359.437974 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.679 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.679 |
| n |
6.000 |
| gf |
0.999 |
| gb |
-0.811 |
| k |
0.996 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
23:18:36.79 |
-17:52:53.8 |
HIP 115144 |
16.18 |
| 2026-09-20 12:00 |
23:18:21.87 |
-17:54:20.8 |
HIP 115144 |
17.96 |
| 2026-09-21 00:00 |
23:18:06.98 |
-17:55:47.2 |
HIP 114970 |
19.75 |
| 2026-09-21 12:00 |
23:17:52.11 |
-17:57:13.0 |
HIP 114970 |
16.33 |
| 2026-09-22 00:00 |
23:17:37.28 |
-17:58:38.1 |
HIP 114970 |
13.15 |
| 2026-09-22 12:00 |
23:17:22.48 |
-18:00:02.5 |
HIP 114970 |
10.40 |
| 2026-09-23 00:00 |
23:17:07.72 |
-18:01:26.2 |
HIP 114970 |
8.51 |
| 2026-09-23 12:00 |
23:16:52.99 |
-18:02:49.3 |
HIP 114970 |
8.08 |
| 2026-09-24 00:00 |
23:16:38.29 |
-18:04:11.7 |
HIP 114970 |
9.30 |
| 2026-09-24 12:00 |
23:16:23.64 |
-18:05:33.5 |
HIP 114970 |
11.65 |
| 2026-09-25 00:00 |
23:16:09.02 |
-18:06:54.5 |
HIP 114970 |
14.58 |
| 2026-09-25 12:00 |
23:15:54.44 |
-18:08:14.8 |
HIP 114970 |
17.81 |
| 2026-09-26 00:00 |
23:15:39.90 |
-18:09:34.5 |
HIP 114970 |
21.18 |
| 2026-09-26 12:00 |
23:15:25.40 |
-18:10:53.5 |
HIP 114970 |
24.64 |
| 2026-09-27 00:00 |
23:15:10.95 |
-18:12:11.7 |
HIP 114970 |
28.14 |
| 2026-09-27 12:00 |
23:14:56.54 |
-18:13:29.3 |
HIP 114630 |
25.29 |
| 2026-09-28 00:00 |
23:14:42.17 |
-18:14:46.1 |
HIP 114630 |
21.65 |
| 2026-09-28 12:00 |
23:14:27.86 |
-18:16:02.2 |
HIP 114630 |
18.02 |
| 2026-09-29 00:00 |
23:14:13.59 |
-18:17:17.6 |
HIP 114630 |
14.41 |
| 2026-09-29 12:00 |
23:13:59.37 |
-18:18:32.3 |
HIP 114630 |
10.81 |
| 2026-09-30 00:00 |
23:13:45.19 |
-18:19:46.2 |
HIP 114630 |
7.23 |
| 2026-09-30 12:00 |
23:13:31.07 |
-18:20:59.4 |
HIP 114630 |
3.66 |
| 2026-10-01 00:00 |
23:13:17.01 |
-18:22:11.9 |
HIP 114630 |
0.13 |
| 2026-10-01 12:00 |
23:13:02.99 |
-18:23:23.7 |
HIP 114630 |
3.42 |
| 2026-10-02 00:00 |
23:12:49.03 |
-18:24:34.7 |
HIP 114630 |
6.94 |
| 2026-10-02 12:00 |
23:12:35.12 |
-18:25:44.9 |
HIP 114630 |
10.44 |
| 2026-10-03 00:00 |
23:12:21.28 |
-18:26:54.4 |
HIP 114630 |
13.92 |
| 2026-10-03 12:00 |
23:12:07.48 |
-18:28:03.2 |
HIP 114630 |
17.38 |
| 2026-10-04 00:00 |
23:11:53.75 |
-18:29:11.2 |
HIP 114478 |
15.43 |
| 2026-10-04 12:00 |
23:11:40.08 |
-18:30:18.4 |
HIP 114478 |
12.26 |
| 2026-10-05 00:00 |
23:11:26.47 |
-18:31:24.9 |
HIP 114478 |
9.29 |
| 2026-10-05 12:00 |
23:11:12.92 |
-18:32:30.6 |
HIP 114478 |
6.76 |
| 2026-10-06 00:00 |
23:10:59.43 |
-18:33:35.5 |
HIP 114478 |
5.32 |
| 2026-10-06 12:00 |
23:10:46.01 |
-18:34:39.6 |
HIP 114478 |
5.80 |
| 2026-10-07 00:00 |
23:10:32.66 |
-18:35:43.0 |
HIP 114478 |
7.83 |
| 2026-10-07 12:00 |
23:10:19.37 |
-18:36:45.6 |
HIP 114478 |
10.54 |
| 2026-10-08 00:00 |
23:10:06.15 |
-18:37:47.4 |
HIP 114338 |
9.71 |
| 2026-10-08 12:00 |
23:09:52.99 |
-18:38:48.4 |
HIP 114338 |
6.70 |
| 2026-10-09 00:00 |
23:09:39.91 |
-18:39:48.7 |
HIP 114338 |
4.12 |
| 2026-10-09 12:00 |
23:09:26.90 |
-18:40:48.1 |
HIP 114338 |
3.20 |
| 2026-10-10 00:00 |
23:09:13.96 |
-18:41:46.8 |
HIP 114338 |
4.93 |
| 2026-10-10 12:00 |
23:09:01.09 |
-18:42:44.6 |
HIP 114276 |
4.90 |
| 2026-10-11 00:00 |
23:08:48.30 |
-18:43:41.7 |
HIP 114276 |
1.90 |