| 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) |
| 2026-06-01 00:00 |
23:52:59.66 |
-12:15:49.1 |
HIP 117747 |
15.10 |
| 2026-06-01 12:00 |
23:53:00.42 |
-12:16:28.5 |
HIP 117747 |
15.78 |
| 2026-06-02 00:00 |
23:53:01.09 |
-12:17:08.7 |
HIP 117747 |
16.47 |
| 2026-06-02 12:00 |
23:53:01.67 |
-12:17:49.5 |
HIP 117747 |
17.16 |
| 2026-06-03 00:00 |
23:53:02.15 |
-12:18:31.1 |
HIP 117747 |
17.87 |
| 2026-06-03 12:00 |
23:53:02.55 |
-12:19:13.3 |
HIP 117747 |
18.58 |
| 2026-06-04 00:00 |
23:53:02.85 |
-12:19:56.3 |
HIP 117747 |
19.29 |
| 2026-06-04 12:00 |
23:53:03.06 |
-12:20:40.0 |
HIP 117747 |
20.02 |
| 2026-06-05 00:00 |
23:53:03.17 |
-12:21:24.4 |
HIP 117747 |
20.75 |
| 2026-06-05 12:00 |
23:53:03.19 |
-12:22:09.5 |
HIP 117747 |
21.49 |
| 2026-06-06 00:00 |
23:53:03.12 |
-12:22:55.4 |
HIP 117747 |
22.24 |
| 2026-06-06 12:00 |
23:53:02.95 |
-12:23:41.9 |
HIP 117747 |
23.00 |
| 2026-06-07 00:00 |
23:53:02.68 |
-12:24:29.2 |
HIP 117747 |
23.76 |
| 2026-06-07 12:00 |
23:53:02.32 |
-12:25:17.2 |
HIP 117747 |
24.54 |
| 2026-06-08 00:00 |
23:53:01.87 |
-12:26:05.9 |
HIP 117747 |
25.33 |
| 2026-06-08 12:00 |
23:53:01.32 |
-12:26:55.3 |
HIP 117747 |
26.13 |
| 2026-06-09 00:00 |
23:53:00.67 |
-12:27:45.5 |
HIP 117747 |
26.94 |
| 2026-06-09 12:00 |
23:52:59.92 |
-12:28:36.3 |
HIP 117747 |
27.76 |
| 2026-06-10 00:00 |
23:52:59.08 |
-12:29:27.9 |
HIP 117747 |
28.59 |
| 2026-06-10 12:00 |
23:52:58.13 |
-12:30:20.2 |
HIP 117747 |
29.44 |
| 2026-06-11 00:00 |
23:52:57.09 |
-12:31:13.2 |
HIP 117747 |
30.30 |
| 2026-06-11 12:00 |
23:52:55.95 |
-12:32:06.9 |
HIP 117747 |
31.17 |
| 2026-06-12 00:00 |
23:52:54.71 |
-12:33:01.4 |
HIP 117747 |
32.06 |
| 2026-06-12 12:00 |
23:52:53.38 |
-12:33:56.6 |
HIP 117595 |
32.62 |
| 2026-06-13 00:00 |
23:52:51.94 |
-12:34:52.4 |
HIP 117595 |
31.88 |
| 2026-06-13 12:00 |
23:52:50.40 |
-12:35:49.0 |
HIP 117595 |
31.12 |
| 2026-06-14 00:00 |
23:52:48.76 |
-12:36:46.3 |
HIP 117595 |
30.36 |
| 2026-06-14 12:00 |
23:52:47.02 |
-12:37:44.4 |
HIP 117595 |
29.58 |
| 2026-06-15 00:00 |
23:52:45.18 |
-12:38:43.1 |
HIP 117595 |
28.80 |
| 2026-06-15 12:00 |
23:52:43.24 |
-12:39:42.5 |
HIP 117595 |
28.00 |
| 2026-06-16 00:00 |
23:52:41.20 |
-12:40:42.7 |
HIP 117595 |
27.20 |
| 2026-06-16 12:00 |
23:52:39.05 |
-12:41:43.6 |
HIP 117595 |
26.40 |
| 2026-06-17 00:00 |
23:52:36.80 |
-12:42:45.1 |
HIP 117595 |
25.59 |
| 2026-06-17 12:00 |
23:52:34.45 |
-12:43:47.4 |
HIP 117595 |
24.79 |
| 2026-06-18 00:00 |
23:52:32.00 |
-12:44:50.4 |
HIP 117595 |
23.99 |
| 2026-06-18 12:00 |
23:52:29.44 |
-12:45:54.1 |
HIP 117595 |
23.20 |
| 2026-06-19 00:00 |
23:52:26.79 |
-12:46:58.4 |
HIP 117595 |
22.43 |
| 2026-06-19 12:00 |
23:52:24.02 |
-12:48:03.5 |
HIP 117595 |
21.67 |
| 2026-06-20 00:00 |
23:52:21.16 |
-12:49:09.3 |
HIP 117595 |
20.94 |
| 2026-06-20 12:00 |
23:52:18.19 |
-12:50:15.7 |
HIP 117595 |
20.24 |
| 2026-06-21 00:00 |
23:52:15.12 |
-12:51:22.9 |
HIP 117595 |
19.58 |
| 2026-06-21 12:00 |
23:52:11.94 |
-12:52:30.7 |
HIP 117595 |
18.97 |
| 2026-06-22 00:00 |
23:52:08.67 |
-12:53:39.2 |
HIP 117595 |
18.43 |