C/2022 A3 (Lemmon-ATLAS)
| Parameter |
Value |
| Designation |
C/2022 A3 (Lemmon-ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-09-28T20:10:26.535360Z |
| Orbit solution date (soln_date, UTC) |
2024-10-31T13:12:14Z |
| Obs used |
1015 |
| NEO |
- |
| M1 |
8.600 |
| K1 |
9.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2022-01-10T10:14:36.297600Z |
| Discovery magnitude (MPC) |
20.34 G |
| Discovery observatory (MPC) |
G96 · Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-02-25.0000000 |
| e |
0.99596960 |
| q (au) |
3.703462 |
| a (au) |
918.881737 |
| i (deg) |
88.348087 |
| Ω (om, deg) |
325.483203 |
| ω (w, deg) |
234.846313 |
| M (ma, deg) |
359.992363 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.660 + 4.723\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.660 |
| n |
4.723 |
| gf |
1.000 |
| gb |
-0.731 |
| k |
0.800 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2021-04-30 |
2023-06-11 |
+0.7727 |
-0.638 |
| 2023-10-09 |
2024-10-29 |
-5.2480 |
+3.736 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
22:28:27.33 |
-40:07:52.3 |
HIP 111000 |
12.84 |
| 2026-02-03 12:00 |
22:28:40.86 |
-40:05:11.3 |
HIP 111026 |
10.74 |
| 2026-02-04 00:00 |
22:28:54.40 |
-40:02:31.0 |
HIP 111026 |
7.50 |
| 2026-02-04 12:00 |
22:29:07.97 |
-39:59:51.5 |
HIP 111026 |
4.97 |
| 2026-02-05 00:00 |
22:29:21.55 |
-39:57:12.6 |
HIP 111026 |
4.54 |
| 2026-02-05 12:00 |
22:29:35.15 |
-39:54:34.5 |
HIP 111026 |
6.63 |
| 2026-02-06 00:00 |
22:29:48.77 |
-39:51:57.1 |
HIP 111026 |
9.72 |
| 2026-02-06 12:00 |
22:30:02.41 |
-39:49:20.4 |
HIP 111026 |
13.13 |
| 2026-02-07 00:00 |
22:30:16.06 |
-39:46:44.5 |
HIP 111026 |
16.65 |
| 2026-02-07 12:00 |
22:30:29.72 |
-39:44:09.2 |
HIP 111199 |
19.93 |
| 2026-02-08 00:00 |
22:30:43.40 |
-39:41:34.8 |
HIP 111199 |
20.36 |
| 2026-02-08 12:00 |
22:30:57.10 |
-39:39:01.0 |
HIP 111226 |
18.84 |
| 2026-02-09 00:00 |
22:31:10.80 |
-39:36:28.0 |
HIP 111226 |
15.17 |
| 2026-02-09 12:00 |
22:31:24.52 |
-39:33:55.7 |
HIP 111226 |
11.51 |
| 2026-02-10 00:00 |
22:31:38.25 |
-39:31:24.1 |
HIP 111226 |
7.86 |
| 2026-02-10 12:00 |
22:31:51.99 |
-39:28:53.3 |
HIP 111226 |
4.23 |
| 2026-02-11 00:00 |
22:32:05.73 |
-39:26:23.2 |
HIP 111226 |
0.85 |
| 2026-02-11 12:00 |
22:32:19.49 |
-39:23:53.9 |
HIP 111226 |
3.18 |
| 2026-02-12 00:00 |
22:32:33.25 |
-39:21:25.4 |
HIP 111226 |
6.78 |
| 2026-02-12 12:00 |
22:32:47.02 |
-39:18:57.6 |
HIP 111226 |
10.39 |
| 2026-02-13 00:00 |
22:33:00.79 |
-39:16:30.5 |
HIP 111226 |
14.01 |
| 2026-02-13 12:00 |
22:33:14.57 |
-39:14:04.2 |
HIP 111226 |
17.62 |
| 2026-02-14 00:00 |
22:33:28.35 |
-39:11:38.7 |
HIP 111226 |
21.23 |
| 2026-02-14 12:00 |
22:33:42.14 |
-39:09:13.9 |
HIP 111226 |
24.83 |
| 2026-02-15 00:00 |
22:33:55.92 |
-39:06:49.9 |
HIP 111226 |
28.42 |
| 2026-02-15 12:00 |
22:34:09.71 |
-39:04:26.7 |
HIP 111513 |
26.73 |
| 2026-02-16 00:00 |
22:34:23.50 |
-39:02:04.2 |
HIP 111513 |
23.21 |
| 2026-02-16 12:00 |
22:34:37.29 |
-38:59:42.6 |
HIP 111513 |
19.73 |
| 2026-02-17 00:00 |
22:34:51.08 |
-38:57:21.7 |
HIP 111513 |
16.30 |
| 2026-02-17 12:00 |
22:35:04.86 |
-38:55:01.5 |
HIP 111513 |
12.95 |
| 2026-02-18 00:00 |
22:35:18.64 |
-38:52:42.2 |
HIP 111513 |
9.76 |
| 2026-02-18 12:00 |
22:35:32.42 |
-38:50:23.7 |
HIP 111513 |
6.94 |
| 2026-02-19 00:00 |
22:35:46.19 |
-38:48:05.9 |
HIP 111513 |
5.13 |
| 2026-02-19 12:00 |
22:35:59.96 |
-38:45:48.9 |
HIP 111513 |
5.43 |
| 2026-02-20 00:00 |
22:36:13.72 |
-38:43:32.8 |
HIP 111513 |
7.58 |
| 2026-02-20 12:00 |
22:36:27.48 |
-38:41:17.4 |
HIP 111513 |
10.49 |
| 2026-02-21 00:00 |
22:36:41.22 |
-38:39:02.8 |
HIP 111513 |
13.68 |
| 2026-02-21 12:00 |
22:36:54.96 |
-38:36:49.0 |
HIP 111513 |
16.99 |
| 2026-02-22 00:00 |
22:37:08.68 |
-38:34:36.1 |
HIP 111513 |
20.35 |
| 2026-02-22 12:00 |
22:37:22.40 |
-38:32:23.9 |
HIP 111815 |
18.62 |
| 2026-02-23 00:00 |
22:37:36.10 |
-38:30:12.5 |
HIP 111815 |
15.64 |
| 2026-02-23 12:00 |
22:37:49.79 |
-38:28:02.0 |
HIP 111815 |
12.90 |
| 2026-02-24 00:00 |
22:38:03.46 |
-38:25:52.2 |
HIP 111815 |
10.58 |