| Parameter |
Value |
| Designation |
C/2022 A2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-02-18T06:27:19.474560Z |
| Orbit solution date (soln_date, UTC) |
2024-08-02T01:42:20Z |
| Obs used |
2731 |
| NEO |
- |
| M1 |
8.300 |
| K1 |
11.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2022-01-10T14:49:09.494400Z |
| Discovery magnitude (MPC) |
20.51 w |
| Discovery observatory (MPC) |
F52 · Pan-STARRS 2, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-04-25.0000000 |
| e |
1.00038112 |
| q (au) |
1.735334 |
| a (au) |
-4553.263121 |
| i (deg) |
108.146714 |
| Ω (om, deg) |
171.579526 |
| ω (w, deg) |
88.367878 |
| M (ma, deg) |
0.000211 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.794 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.794 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.798 |
| k |
0.997 |
| 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 |
| 2022-01-09 |
2023-02-17 |
+2.8312 |
-1.497 |
| 2023-02-18 |
2023-08-21 |
+5.2261 |
-2.663 |
| 2023-08-21 |
2024-08-01 |
-3.9154 |
+1.262 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
00:08:17.41 |
-40:48:26.4 |
HIP 774 |
17.05 |
| 2026-05-12 12:00 |
00:08:26.07 |
-40:49:44.6 |
HIP 791 |
16.04 |
| 2026-05-13 00:00 |
00:08:34.65 |
-40:51:03.8 |
HIP 791 |
14.17 |
| 2026-05-13 12:00 |
00:08:43.16 |
-40:52:23.8 |
HIP 791 |
12.40 |
| 2026-05-14 00:00 |
00:08:51.60 |
-40:53:44.8 |
HIP 762 |
10.73 |
| 2026-05-14 12:00 |
00:08:59.96 |
-40:55:06.6 |
HIP 762 |
8.73 |
| 2026-05-15 00:00 |
00:09:08.25 |
-40:56:29.4 |
HIP 762 |
6.78 |
| 2026-05-15 12:00 |
00:09:16.46 |
-40:57:53.0 |
HIP 762 |
4.94 |
| 2026-05-16 00:00 |
00:09:24.60 |
-40:59:17.5 |
HIP 762 |
3.37 |
| 2026-05-16 12:00 |
00:09:32.66 |
-41:00:42.9 |
HIP 762 |
2.62 |
| 2026-05-17 00:00 |
00:09:40.64 |
-41:02:09.2 |
HIP 762 |
3.31 |
| 2026-05-17 12:00 |
00:09:48.55 |
-41:03:36.4 |
HIP 762 |
4.86 |
| 2026-05-18 00:00 |
00:09:56.37 |
-41:05:04.4 |
HIP 762 |
6.69 |
| 2026-05-18 12:00 |
00:10:04.12 |
-41:06:33.4 |
HIP 861 |
6.16 |
| 2026-05-19 00:00 |
00:10:11.79 |
-41:08:03.2 |
HIP 861 |
4.78 |
| 2026-05-19 12:00 |
00:10:19.37 |
-41:09:33.8 |
HIP 861 |
4.07 |
| 2026-05-20 00:00 |
00:10:26.88 |
-41:11:05.4 |
HIP 861 |
4.38 |
| 2026-05-20 12:00 |
00:10:34.31 |
-41:12:37.8 |
HIP 861 |
5.53 |
| 2026-05-21 00:00 |
00:10:41.65 |
-41:14:11.0 |
HIP 861 |
7.13 |
| 2026-05-21 12:00 |
00:10:48.91 |
-41:15:45.2 |
HIP 861 |
8.94 |
| 2026-05-22 00:00 |
00:10:56.08 |
-41:17:20.2 |
HIP 861 |
10.85 |
| 2026-05-22 12:00 |
00:11:03.18 |
-41:18:56.0 |
HIP 861 |
12.83 |
| 2026-05-23 00:00 |
00:11:10.19 |
-41:20:32.7 |
HIP 861 |
14.83 |
| 2026-05-23 12:00 |
00:11:17.11 |
-41:22:10.2 |
HIP 861 |
16.87 |
| 2026-05-24 00:00 |
00:11:23.95 |
-41:23:48.5 |
HIP 861 |
18.91 |
| 2026-05-24 12:00 |
00:11:30.71 |
-41:25:27.7 |
HIP 861 |
20.97 |
| 2026-05-25 00:00 |
00:11:37.37 |
-41:27:07.8 |
HIP 861 |
23.04 |
| 2026-05-25 12:00 |
00:11:43.96 |
-41:28:48.6 |
HIP 861 |
25.11 |
| 2026-05-26 00:00 |
00:11:50.45 |
-41:30:30.3 |
HIP 861 |
27.19 |
| 2026-05-26 12:00 |
00:11:56.86 |
-41:32:12.8 |
HIP 861 |
29.27 |
| 2026-05-27 00:00 |
00:12:03.18 |
-41:33:56.1 |
HIP 861 |
31.35 |
| 2026-05-27 12:00 |
00:12:09.41 |
-41:35:40.3 |
HIP 861 |
33.44 |
| 2026-05-28 00:00 |
00:12:15.55 |
-41:37:25.2 |
HIP 966 |
33.10 |
| 2026-05-28 12:00 |
00:12:21.60 |
-41:39:11.0 |
HIP 966 |
31.50 |
| 2026-05-29 00:00 |
00:12:27.56 |
-41:40:57.5 |
HIP 966 |
29.94 |
| 2026-05-29 12:00 |
00:12:33.44 |
-41:42:44.9 |
HIP 966 |
28.43 |
| 2026-05-30 00:00 |
00:12:39.22 |
-41:44:33.0 |
HIP 966 |
26.99 |
| 2026-05-30 12:00 |
00:12:44.91 |
-41:46:22.0 |
HIP 966 |
25.61 |
| 2026-05-31 00:00 |
00:12:50.51 |
-41:48:11.7 |
HIP 966 |
24.33 |
| 2026-05-31 12:00 |
00:12:56.01 |
-41:50:02.2 |
HIP 966 |
23.14 |
| 2026-06-01 00:00 |
00:13:01.43 |
-41:51:53.5 |
HIP 966 |
22.06 |
| 2026-06-01 12:00 |
00:13:06.75 |
-41:53:45.6 |
HIP 966 |
21.13 |
| 2026-06-02 00:00 |
00:13:11.97 |
-41:55:38.4 |
HIP 966 |
20.34 |