| 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 · 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 |
1.000 |
| 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) |
| 2026-05-12 00:00 |
23:51:18.83 |
-11:59:07.7 |
HIP 117696 |
20.26 |
| 2026-05-12 12:00 |
23:51:22.91 |
-11:59:19.3 |
HIP 117696 |
19.82 |
| 2026-05-13 00:00 |
23:51:26.92 |
-11:59:31.6 |
HIP 117696 |
19.43 |
| 2026-05-13 12:00 |
23:51:30.85 |
-11:59:44.6 |
HIP 117747 |
18.80 |
| 2026-05-14 00:00 |
23:51:34.71 |
-11:59:58.2 |
HIP 117747 |
17.85 |
| 2026-05-14 12:00 |
23:51:38.49 |
-12:00:12.6 |
HIP 117747 |
16.91 |
| 2026-05-15 00:00 |
23:51:42.19 |
-12:00:27.5 |
HIP 117747 |
15.99 |
| 2026-05-15 12:00 |
23:51:45.82 |
-12:00:43.2 |
HIP 117747 |
15.10 |
| 2026-05-16 00:00 |
23:51:49.38 |
-12:00:59.5 |
HIP 117747 |
14.23 |
| 2026-05-16 12:00 |
23:51:52.85 |
-12:01:16.6 |
HIP 117747 |
13.38 |
| 2026-05-17 00:00 |
23:51:56.25 |
-12:01:34.3 |
HIP 117747 |
12.56 |
| 2026-05-17 12:00 |
23:51:59.57 |
-12:01:52.7 |
HIP 117747 |
11.77 |
| 2026-05-18 00:00 |
23:52:02.81 |
-12:02:11.7 |
HIP 117747 |
11.01 |
| 2026-05-18 12:00 |
23:52:05.97 |
-12:02:31.5 |
HIP 117747 |
10.28 |
| 2026-05-19 00:00 |
23:52:09.05 |
-12:02:51.9 |
HIP 117747 |
9.60 |
| 2026-05-19 12:00 |
23:52:12.05 |
-12:03:13.1 |
HIP 117747 |
8.96 |
| 2026-05-20 00:00 |
23:52:14.97 |
-12:03:34.9 |
HIP 117747 |
8.37 |
| 2026-05-20 12:00 |
23:52:17.81 |
-12:03:57.5 |
HIP 117747 |
7.85 |
| 2026-05-21 00:00 |
23:52:20.57 |
-12:04:20.7 |
HIP 117747 |
7.40 |
| 2026-05-21 12:00 |
23:52:23.24 |
-12:04:44.6 |
HIP 117747 |
7.02 |
| 2026-05-22 00:00 |
23:52:25.83 |
-12:05:09.2 |
HIP 117747 |
6.74 |
| 2026-05-22 12:00 |
23:52:28.34 |
-12:05:34.6 |
HIP 117747 |
6.55 |
| 2026-05-23 00:00 |
23:52:30.76 |
-12:06:00.6 |
HIP 117747 |
6.47 |
| 2026-05-23 12:00 |
23:52:33.10 |
-12:06:27.3 |
HIP 117747 |
6.49 |
| 2026-05-24 00:00 |
23:52:35.36 |
-12:06:54.7 |
HIP 117747 |
6.61 |
| 2026-05-24 12:00 |
23:52:37.53 |
-12:07:22.8 |
HIP 117747 |
6.83 |
| 2026-05-25 00:00 |
23:52:39.62 |
-12:07:51.6 |
HIP 117747 |
7.12 |
| 2026-05-25 12:00 |
23:52:41.62 |
-12:08:21.2 |
HIP 117747 |
7.48 |
| 2026-05-26 00:00 |
23:52:43.53 |
-12:08:51.4 |
HIP 117747 |
7.91 |
| 2026-05-26 12:00 |
23:52:45.36 |
-12:09:22.3 |
HIP 117747 |
8.38 |
| 2026-05-27 00:00 |
23:52:47.10 |
-12:09:53.9 |
HIP 117747 |
8.89 |
| 2026-05-27 12:00 |
23:52:48.75 |
-12:10:26.3 |
HIP 117747 |
9.43 |
| 2026-05-28 00:00 |
23:52:50.32 |
-12:10:59.3 |
HIP 117747 |
10.00 |
| 2026-05-28 12:00 |
23:52:51.80 |
-12:11:33.1 |
HIP 117747 |
10.59 |
| 2026-05-29 00:00 |
23:52:53.19 |
-12:12:07.5 |
HIP 117747 |
11.20 |
| 2026-05-29 12:00 |
23:52:54.49 |
-12:12:42.7 |
HIP 117747 |
11.82 |
| 2026-05-30 00:00 |
23:52:55.70 |
-12:13:18.5 |
HIP 117747 |
12.46 |
| 2026-05-30 12:00 |
23:52:56.83 |
-12:13:55.1 |
HIP 117747 |
13.10 |
| 2026-05-31 00:00 |
23:52:57.86 |
-12:14:32.4 |
HIP 117747 |
13.76 |
| 2026-05-31 12:00 |
23:52:58.80 |
-12:15:10.4 |
HIP 117747 |
14.43 |
| 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 |