C/2022 Y2 (Lemmon)
| 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) |
| 2026-02-03 00:00 |
23:26:30.17 |
-13:48:40.1 |
HIP 115626 |
20.02 |
| 2026-02-03 12:00 |
23:26:37.24 |
-13:47:46.0 |
HIP 115626 |
21.93 |
| 2026-02-04 00:00 |
23:26:44.37 |
-13:46:51.8 |
HIP 115626 |
23.85 |
| 2026-02-04 12:00 |
23:26:51.54 |
-13:45:57.6 |
HIP 115626 |
25.79 |
| 2026-02-05 00:00 |
23:26:58.76 |
-13:45:03.4 |
HIP 115626 |
27.75 |
| 2026-02-05 12:00 |
23:27:06.03 |
-13:44:09.0 |
HIP 115626 |
29.72 |
| 2026-02-06 00:00 |
23:27:13.35 |
-13:43:14.6 |
HIP 115886 |
29.07 |
| 2026-02-06 12:00 |
23:27:20.71 |
-13:42:20.2 |
HIP 115886 |
28.36 |
| 2026-02-07 00:00 |
23:27:28.12 |
-13:41:25.7 |
HIP 115886 |
27.78 |
| 2026-02-07 12:00 |
23:27:35.57 |
-13:40:31.2 |
HIP 115886 |
27.32 |
| 2026-02-08 00:00 |
23:27:43.06 |
-13:39:36.7 |
HIP 115886 |
27.00 |
| 2026-02-08 12:00 |
23:27:50.60 |
-13:38:42.1 |
HIP 115886 |
26.83 |
| 2026-02-09 00:00 |
23:27:58.18 |
-13:37:47.5 |
HIP 115886 |
26.80 |
| 2026-02-09 12:00 |
23:28:05.81 |
-13:36:52.8 |
HIP 115886 |
26.93 |
| 2026-02-10 00:00 |
23:28:13.47 |
-13:35:58.2 |
HIP 115954 |
25.90 |
| 2026-02-10 12:00 |
23:28:21.18 |
-13:35:03.5 |
HIP 115954 |
23.90 |
| 2026-02-11 00:00 |
23:28:28.92 |
-13:34:08.8 |
HIP 115954 |
21.90 |
| 2026-02-11 12:00 |
23:28:36.71 |
-13:33:14.2 |
HIP 115954 |
19.92 |
| 2026-02-12 00:00 |
23:28:44.53 |
-13:32:19.5 |
HIP 115954 |
17.95 |
| 2026-02-12 12:00 |
23:28:52.39 |
-13:31:24.8 |
HIP 115954 |
16.02 |
| 2026-02-13 00:00 |
23:29:00.28 |
-13:30:30.2 |
HIP 115954 |
14.14 |
| 2026-02-13 12:00 |
23:29:08.22 |
-13:29:35.6 |
HIP 115954 |
12.33 |
| 2026-02-14 00:00 |
23:29:16.19 |
-13:28:40.9 |
HIP 115954 |
10.63 |
| 2026-02-14 12:00 |
23:29:24.19 |
-13:27:46.4 |
HIP 115954 |
9.13 |
| 2026-02-15 00:00 |
23:29:32.23 |
-13:26:51.8 |
HIP 115954 |
7.93 |
| 2026-02-15 12:00 |
23:29:40.30 |
-13:25:57.3 |
HIP 115954 |
7.19 |
| 2026-02-16 00:00 |
23:29:48.40 |
-13:25:02.8 |
HIP 115954 |
7.06 |
| 2026-02-16 12:00 |
23:29:56.53 |
-13:24:08.4 |
HIP 115954 |
7.59 |
| 2026-02-17 00:00 |
23:30:04.70 |
-13:23:14.0 |
HIP 115954 |
8.66 |
| 2026-02-17 12:00 |
23:30:12.89 |
-13:22:19.7 |
HIP 116041 |
8.94 |
| 2026-02-18 00:00 |
23:30:21.12 |
-13:21:25.4 |
HIP 116041 |
6.75 |
| 2026-02-18 12:00 |
23:30:29.37 |
-13:20:31.2 |
HIP 116041 |
4.56 |
| 2026-02-19 00:00 |
23:30:37.65 |
-13:19:37.1 |
HIP 116041 |
2.37 |
| 2026-02-19 12:00 |
23:30:45.96 |
-13:18:43.1 |
HIP 116041 |
0.49 |
| 2026-02-20 00:00 |
23:30:54.29 |
-13:17:49.1 |
HIP 116041 |
2.16 |
| 2026-02-20 12:00 |
23:31:02.65 |
-13:16:55.2 |
HIP 116041 |
4.36 |
| 2026-02-21 00:00 |
23:31:11.04 |
-13:16:01.4 |
HIP 116041 |
6.58 |
| 2026-02-21 12:00 |
23:31:19.45 |
-13:15:07.8 |
HIP 116041 |
8.81 |
| 2026-02-22 00:00 |
23:31:27.88 |
-13:14:14.2 |
HIP 116041 |
11.04 |
| 2026-02-22 12:00 |
23:31:36.34 |
-13:13:20.7 |
HIP 116178 |
12.13 |
| 2026-02-23 00:00 |
23:31:44.81 |
-13:12:27.3 |
HIP 116178 |
10.64 |
| 2026-02-23 12:00 |
23:31:53.31 |
-13:11:34.1 |
HIP 116178 |
9.45 |
| 2026-02-24 00:00 |
23:32:01.83 |
-13:10:41.0 |
HIP 116178 |
8.68 |