| 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 |
0.999 |
| 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 |
+5.2262 |
-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) |
| 2026-06-01 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 |
| 2026-06-02 12:00 |
00:13:17.10 |
-41:57:32.0 |
HIP 966 |
19.73 |
| 2026-06-03 00:00 |
00:13:22.14 |
-41:59:26.4 |
HIP 966 |
19.32 |
| 2026-06-03 12:00 |
00:13:27.08 |
-42:01:21.5 |
HIP 966 |
19.11 |
| 2026-06-04 00:00 |
00:13:31.93 |
-42:03:17.4 |
HIP 1221 |
19.07 |
| 2026-06-04 12:00 |
00:13:36.68 |
-42:05:14.1 |
HIP 1221 |
17.99 |
| 2026-06-05 00:00 |
00:13:41.33 |
-42:07:11.4 |
HIP 1221 |
17.13 |
| 2026-06-05 12:00 |
00:13:45.88 |
-42:09:09.6 |
HIP 1221 |
16.52 |
| 2026-06-06 00:00 |
00:13:50.34 |
-42:11:08.4 |
HIP 1228 |
15.93 |
| 2026-06-06 12:00 |
00:13:54.70 |
-42:13:08.0 |
HIP 1228 |
15.41 |
| 2026-06-07 00:00 |
00:13:58.96 |
-42:15:08.4 |
HIP 1228 |
15.21 |
| 2026-06-07 12:00 |
00:14:03.12 |
-42:17:09.4 |
HIP 1228 |
15.33 |
| 2026-06-08 00:00 |
00:14:07.18 |
-42:19:11.2 |
HIP 1228 |
15.77 |
| 2026-06-08 12:00 |
00:14:11.14 |
-42:21:13.7 |
HIP 1232 |
14.97 |
| 2026-06-09 00:00 |
00:14:15.00 |
-42:23:16.9 |
HIP 1232 |
13.27 |
| 2026-06-09 12:00 |
00:14:18.75 |
-42:25:20.8 |
HIP 1232 |
11.74 |
| 2026-06-10 00:00 |
00:14:22.41 |
-42:27:25.4 |
HIP 1232 |
10.46 |
| 2026-06-10 12:00 |
00:14:25.96 |
-42:29:30.7 |
HIP 1232 |
9.53 |
| 2026-06-11 00:00 |
00:14:29.41 |
-42:31:36.7 |
HIP 1232 |
9.08 |
| 2026-06-11 12:00 |
00:14:32.75 |
-42:33:43.3 |
HIP 1232 |
9.16 |
| 2026-06-12 00:00 |
00:14:35.99 |
-42:35:50.7 |
HIP 1232 |
9.77 |
| 2026-06-12 12:00 |
00:14:39.12 |
-42:37:58.7 |
HIP 1232 |
10.83 |
| 2026-06-13 00:00 |
00:14:42.15 |
-42:40:07.4 |
HIP 1232 |
12.22 |
| 2026-06-13 12:00 |
00:14:45.08 |
-42:42:16.7 |
HIP 1232 |
13.85 |
| 2026-06-14 00:00 |
00:14:47.89 |
-42:44:26.7 |
HIP 1279 |
14.34 |
| 2026-06-14 12:00 |
00:14:50.60 |
-42:46:37.3 |
HIP 1279 |
14.67 |
| 2026-06-15 00:00 |
00:14:53.20 |
-42:48:48.6 |
HIP 1279 |
15.34 |
| 2026-06-15 12:00 |
00:14:55.70 |
-42:51:00.5 |
HIP 1279 |
16.31 |
| 2026-06-16 00:00 |
00:14:58.08 |
-42:53:13.0 |
HIP 1279 |
17.54 |
| 2026-06-16 12:00 |
00:15:00.36 |
-42:55:26.1 |
HIP 1280 |
16.33 |
| 2026-06-17 00:00 |
00:15:02.53 |
-42:57:39.8 |
HIP 1280 |
14.51 |
| 2026-06-17 12:00 |
00:15:04.58 |
-42:59:54.1 |
HIP 1280 |
12.84 |
| 2026-06-18 00:00 |
00:15:06.53 |
-43:02:09.0 |
HIP 1280 |
11.40 |
| 2026-06-18 12:00 |
00:15:08.37 |
-43:04:24.5 |
HIP 1280 |
10.28 |
| 2026-06-19 00:00 |
00:15:10.09 |
-43:06:40.6 |
HIP 1280 |
9.60 |
| 2026-06-19 12:00 |
00:15:11.71 |
-43:08:57.2 |
HIP 1280 |
9.47 |
| 2026-06-20 00:00 |
00:15:13.21 |
-43:11:14.4 |
HIP 1280 |
9.91 |
| 2026-06-20 12:00 |
00:15:14.60 |
-43:13:32.2 |
HIP 1280 |
10.85 |
| 2026-06-21 00:00 |
00:15:15.88 |
-43:15:50.4 |
HIP 1280 |
12.18 |
| 2026-06-21 12:00 |
00:15:17.05 |
-43:18:09.2 |
HIP 1280 |
13.80 |
| 2026-06-22 00:00 |
00:15:18.11 |
-43:20:28.6 |
HIP 1280 |
15.61 |