| Parameter |
Value |
| Designation |
C/2021 A6 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-05-04T03:17:13.050240Z |
| Orbit solution date (soln_date, UTC) |
2024-08-02T01:42:19Z |
| Obs used |
167 |
| NEO |
- |
| M1 |
5.100 |
| K1 |
12.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-01-08T14:28:45.120000Z |
| Discovery magnitude (MPC) |
20.89 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2022-03-24.0000000 |
| e |
0.99923094 |
| q (au) |
7.928456 |
| a (au) |
10309.304354 |
| i (deg) |
75.612049 |
| Ω (om, deg) |
164.079307 |
| ω (w, deg) |
351.692611 |
| M (ma, deg) |
0.000305 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.232 + 4.625\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.232 |
| n |
4.625 |
| gf |
0.972 |
| gb |
-0.874 |
| k |
1.000 |
| δ90 |
9.788 |
| 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) |
| 2026-06-01 00:00 |
15:18:44.13 |
+55:47:31.3 |
HIP 75205 |
29.27 |
| 2026-06-01 12:00 |
15:18:34.26 |
+55:47:10.2 |
HIP 75205 |
30.56 |
| 2026-06-02 00:00 |
15:18:24.43 |
+55:46:48.0 |
HIP 75205 |
31.86 |
| 2026-06-02 12:00 |
15:18:14.66 |
+55:46:24.8 |
HIP 75205 |
33.16 |
| 2026-06-03 00:00 |
15:18:04.94 |
+55:46:00.4 |
HIP 75088 |
34.23 |
| 2026-06-03 12:00 |
15:17:55.27 |
+55:45:35.0 |
HIP 75088 |
34.79 |
| 2026-06-04 00:00 |
15:17:45.66 |
+55:45:08.5 |
HIP 75088 |
35.38 |
| 2026-06-04 12:00 |
15:17:36.11 |
+55:44:41.0 |
HIP 75088 |
36.01 |
| 2026-06-05 00:00 |
15:17:26.62 |
+55:44:12.3 |
HIP 75088 |
36.66 |
| 2026-06-05 12:00 |
15:17:17.18 |
+55:43:42.7 |
HIP 74522 |
35.65 |
| 2026-06-06 00:00 |
15:17:07.81 |
+55:43:11.9 |
HIP 74522 |
34.26 |
| 2026-06-06 12:00 |
15:16:58.50 |
+55:42:40.2 |
HIP 74522 |
32.86 |
| 2026-06-07 00:00 |
15:16:49.25 |
+55:42:07.4 |
HIP 74522 |
31.46 |
| 2026-06-07 12:00 |
15:16:40.06 |
+55:41:33.5 |
HIP 74522 |
30.06 |
| 2026-06-08 00:00 |
15:16:30.94 |
+55:40:58.6 |
HIP 74522 |
28.67 |
| 2026-06-08 12:00 |
15:16:21.88 |
+55:40:22.7 |
HIP 74522 |
27.27 |
| 2026-06-09 00:00 |
15:16:12.89 |
+55:39:45.8 |
HIP 74522 |
25.87 |
| 2026-06-09 12:00 |
15:16:03.97 |
+55:39:07.8 |
HIP 74522 |
24.47 |
| 2026-06-10 00:00 |
15:15:55.12 |
+55:38:28.8 |
HIP 74522 |
23.07 |
| 2026-06-10 12:00 |
15:15:46.33 |
+55:37:48.8 |
HIP 74522 |
21.67 |
| 2026-06-11 00:00 |
15:15:37.62 |
+55:37:07.9 |
HIP 74522 |
20.27 |
| 2026-06-11 12:00 |
15:15:28.98 |
+55:36:25.9 |
HIP 74522 |
18.87 |
| 2026-06-12 00:00 |
15:15:20.42 |
+55:35:42.9 |
HIP 74522 |
17.47 |
| 2026-06-12 12:00 |
15:15:11.93 |
+55:34:58.9 |
HIP 74522 |
16.07 |
| 2026-06-13 00:00 |
15:15:03.51 |
+55:34:14.0 |
HIP 74522 |
14.66 |
| 2026-06-13 12:00 |
15:14:55.17 |
+55:33:28.1 |
HIP 74522 |
13.26 |
| 2026-06-14 00:00 |
15:14:46.91 |
+55:32:41.2 |
HIP 74522 |
11.86 |
| 2026-06-14 12:00 |
15:14:38.73 |
+55:31:53.3 |
HIP 74522 |
10.45 |
| 2026-06-15 00:00 |
15:14:30.62 |
+55:31:04.5 |
HIP 74522 |
9.05 |
| 2026-06-15 12:00 |
15:14:22.60 |
+55:30:14.7 |
HIP 74522 |
7.64 |
| 2026-06-16 00:00 |
15:14:14.66 |
+55:29:24.0 |
HIP 74522 |
6.23 |
| 2026-06-16 12:00 |
15:14:06.80 |
+55:28:32.4 |
HIP 74522 |
4.83 |
| 2026-06-17 00:00 |
15:13:59.02 |
+55:27:39.8 |
HIP 74522 |
3.42 |
| 2026-06-17 12:00 |
15:13:51.33 |
+55:26:46.3 |
HIP 74522 |
2.01 |
| 2026-06-18 00:00 |
15:13:43.72 |
+55:25:51.9 |
HIP 74522 |
0.61 |
| 2026-06-18 12:00 |
15:13:36.20 |
+55:24:56.6 |
HIP 74522 |
0.82 |
| 2026-06-19 00:00 |
15:13:28.77 |
+55:24:00.4 |
HIP 74522 |
2.22 |
| 2026-06-19 12:00 |
15:13:21.42 |
+55:23:03.3 |
HIP 74522 |
3.64 |
| 2026-06-20 00:00 |
15:13:14.17 |
+55:22:05.3 |
HIP 74522 |
5.05 |
| 2026-06-20 12:00 |
15:13:07.00 |
+55:21:06.4 |
HIP 74522 |
6.46 |
| 2026-06-21 00:00 |
15:12:59.92 |
+55:20:06.7 |
HIP 74522 |
7.88 |
| 2026-06-21 12:00 |
15:12:52.93 |
+55:19:06.1 |
HIP 74522 |
9.29 |
| 2026-06-22 00:00 |
15:12:46.04 |
+55:18:04.7 |
HIP 74522 |
10.71 |