| 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) |
| 2026-07-29 00:00 |
23:43:17.50 |
-14:45:28.0 |
HIP 116971 |
15.23 |
| 2026-07-29 12:00 |
23:43:06.58 |
-14:47:15.8 |
HIP 116971 |
15.63 |
| 2026-07-30 00:00 |
23:42:55.58 |
-14:49:03.9 |
HIP 116971 |
16.65 |
| 2026-07-30 12:00 |
23:42:44.49 |
-14:50:52.3 |
HIP 116971 |
18.19 |
| 2026-07-31 00:00 |
23:42:33.32 |
-14:52:40.9 |
HIP 116971 |
20.14 |
| 2026-07-31 12:00 |
23:42:22.05 |
-14:54:29.8 |
HIP 116971 |
22.41 |
| 2026-08-01 00:00 |
23:42:10.70 |
-14:56:19.0 |
HIP 116971 |
24.91 |
| 2026-08-01 12:00 |
23:41:59.26 |
-14:58:08.4 |
HIP 116971 |
27.59 |
| 2026-08-02 00:00 |
23:41:47.74 |
-14:59:58.0 |
HIP 116922 |
27.94 |
| 2026-08-02 12:00 |
23:41:36.13 |
-15:01:47.9 |
HIP 116922 |
26.54 |
| 2026-08-03 00:00 |
23:41:24.43 |
-15:03:37.9 |
HIP 116922 |
25.50 |
| 2026-08-03 12:00 |
23:41:12.65 |
-15:05:28.2 |
HIP 116792 |
24.35 |
| 2026-08-04 00:00 |
23:41:00.79 |
-15:07:18.7 |
HIP 116792 |
21.23 |
| 2026-08-04 12:00 |
23:40:48.85 |
-15:09:09.4 |
HIP 116792 |
18.19 |
| 2026-08-05 00:00 |
23:40:36.82 |
-15:11:00.3 |
HIP 116792 |
15.30 |
| 2026-08-05 12:00 |
23:40:24.72 |
-15:12:51.3 |
HIP 116792 |
12.69 |
| 2026-08-06 00:00 |
23:40:12.53 |
-15:14:42.5 |
HIP 116792 |
10.57 |
| 2026-08-06 12:00 |
23:40:00.27 |
-15:16:33.9 |
HIP 116792 |
9.30 |
| 2026-08-07 00:00 |
23:39:47.92 |
-15:18:25.4 |
HIP 116792 |
9.27 |
| 2026-08-07 12:00 |
23:39:35.50 |
-15:20:17.1 |
HIP 116792 |
10.51 |
| 2026-08-08 00:00 |
23:39:23.00 |
-15:22:08.9 |
HIP 116792 |
12.65 |
| 2026-08-08 12:00 |
23:39:10.42 |
-15:24:00.8 |
HIP 116792 |
15.35 |
| 2026-08-09 00:00 |
23:38:57.77 |
-15:25:52.8 |
HIP 116792 |
18.35 |
| 2026-08-09 12:00 |
23:38:45.04 |
-15:27:45.0 |
HIP 116792 |
21.55 |
| 2026-08-10 00:00 |
23:38:32.24 |
-15:29:37.2 |
HIP 116590 |
21.23 |
| 2026-08-10 12:00 |
23:38:19.36 |
-15:31:29.5 |
HIP 116590 |
21.10 |
| 2026-08-11 00:00 |
23:38:06.42 |
-15:33:21.9 |
HIP 116590 |
21.59 |
| 2026-08-11 12:00 |
23:37:53.40 |
-15:35:14.4 |
HIP 116590 |
22.66 |
| 2026-08-12 00:00 |
23:37:40.31 |
-15:37:06.9 |
HIP 116590 |
24.24 |
| 2026-08-12 12:00 |
23:37:27.16 |
-15:38:59.4 |
HIP 116590 |
26.24 |
| 2026-08-13 00:00 |
23:37:13.93 |
-15:40:52.0 |
HIP 116590 |
28.59 |
| 2026-08-13 12:00 |
23:37:00.64 |
-15:42:44.6 |
HIP 116590 |
31.20 |
| 2026-08-14 00:00 |
23:36:47.28 |
-15:44:37.2 |
HIP 116438 |
30.99 |
| 2026-08-14 12:00 |
23:36:33.86 |
-15:46:29.8 |
HIP 116438 |
31.18 |
| 2026-08-15 00:00 |
23:36:20.37 |
-15:48:22.4 |
HIP 116468 |
29.51 |
| 2026-08-15 12:00 |
23:36:06.82 |
-15:50:15.0 |
HIP 116468 |
27.20 |
| 2026-08-16 00:00 |
23:35:53.21 |
-15:52:07.6 |
HIP 116468 |
25.26 |
| 2026-08-16 12:00 |
23:35:39.54 |
-15:54:00.1 |
HIP 116468 |
23.75 |
| 2026-08-17 00:00 |
23:35:25.80 |
-15:55:52.6 |
HIP 116468 |
22.79 |
| 2026-08-17 12:00 |
23:35:12.01 |
-15:57:45.0 |
HIP 116468 |
22.44 |
| 2026-08-18 00:00 |
23:34:58.17 |
-15:59:37.3 |
HIP 116468 |
22.74 |
| 2026-08-18 12:00 |
23:34:44.26 |
-16:01:29.6 |
HIP 116302 |
21.32 |
| 2026-08-19 00:00 |
23:34:30.30 |
-16:03:21.7 |
HIP 116302 |
17.92 |