| Parameter |
Value |
| Designation |
P/2021 A5 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2020-11-13T00:03:53.236800Z |
| Orbit solution date (soln_date, UTC) |
2025-01-14T17:42:18Z |
| Obs used |
47 |
| NEO |
- |
| M1 |
15.000 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-01-06T07:09:10.742400Z |
| Discovery magnitude (MPC) |
21.24 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-01-05.0000000 |
| e |
0.14092491 |
| q (au) |
2.622101 |
| a (au) |
3.052238 |
| i (deg) |
18.186098 |
| Ω (om, deg) |
328.718645 |
| ω (w, deg) |
61.512717 |
| M (ma, deg) |
9.795583 |
Magnitude
Scatter + Global Linear
$$
M_a = (16.273 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
16.273 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.501 |
| k |
1.000 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
03:14:09.20 |
+31:38:28.2 |
HIP 15226 |
32.17 |
| 2026-06-01 12:00 |
03:15:08.44 |
+31:42:41.7 |
HIP 15226 |
19.50 |
| 2026-06-02 00:00 |
03:16:07.73 |
+31:46:54.3 |
HIP 15226 |
8.89 |
| 2026-06-02 12:00 |
03:17:07.05 |
+31:51:05.9 |
HIP 15226 |
11.43 |
| 2026-06-03 00:00 |
03:18:06.40 |
+31:55:16.6 |
HIP 15226 |
23.12 |
| 2026-06-03 12:00 |
03:19:05.80 |
+31:59:26.2 |
HIP 15530 |
12.90 |
| 2026-06-04 00:00 |
03:20:05.23 |
+32:03:34.9 |
HIP 15530 |
2.29 |
| 2026-06-04 12:00 |
03:21:04.69 |
+32:07:42.6 |
HIP 15530 |
13.99 |
| 2026-06-05 00:00 |
03:22:04.19 |
+32:11:49.2 |
HIP 15721 |
6.25 |
| 2026-06-05 12:00 |
03:23:03.73 |
+32:15:54.9 |
HIP 15721 |
7.06 |
| 2026-06-06 00:00 |
03:24:03.30 |
+32:19:59.5 |
HIP 15937 |
15.05 |
| 2026-06-06 12:00 |
03:25:02.90 |
+32:24:03.2 |
HIP 15937 |
2.55 |
| 2026-06-07 00:00 |
03:26:02.54 |
+32:28:05.8 |
HIP 15937 |
11.67 |
| 2026-06-07 12:00 |
03:27:02.21 |
+32:32:07.4 |
HIP 16154 |
21.92 |
| 2026-06-08 00:00 |
03:28:01.92 |
+32:36:08.1 |
HIP 16154 |
12.68 |
| 2026-06-08 12:00 |
03:29:01.65 |
+32:40:07.6 |
HIP 16154 |
13.77 |
| 2026-06-09 00:00 |
03:30:01.42 |
+32:44:06.2 |
HIP 16154 |
23.79 |
| 2026-06-09 12:00 |
03:31:01.22 |
+32:48:03.7 |
HIP 16408 |
28.42 |
| 2026-06-10 00:00 |
03:32:01.05 |
+32:52:00.2 |
HIP 16557 |
33.07 |
| 2026-06-10 12:00 |
03:33:00.91 |
+32:55:55.6 |
HIP 16676 |
20.44 |
| 2026-06-11 00:00 |
03:34:00.80 |
+32:59:50.1 |
HIP 16676 |
7.46 |
| 2026-06-11 12:00 |
03:35:00.71 |
+33:03:43.4 |
HIP 16676 |
6.29 |
| 2026-06-12 00:00 |
03:36:00.65 |
+33:07:35.7 |
HIP 16676 |
19.20 |
| 2026-06-12 12:00 |
03:37:00.62 |
+33:11:27.0 |
HIP 16676 |
32.29 |
| 2026-06-13 00:00 |
03:38:00.62 |
+33:15:17.2 |
HIP 17102 |
26.16 |
| 2026-06-13 12:00 |
03:39:00.64 |
+33:19:06.4 |
HIP 17102 |
13.72 |
| 2026-06-14 00:00 |
03:40:00.68 |
+33:22:54.5 |
HIP 17102 |
6.02 |
| 2026-06-14 12:00 |
03:41:00.75 |
+33:26:41.5 |
HIP 17177 |
11.87 |
| 2026-06-15 00:00 |
03:42:00.84 |
+33:30:27.4 |
HIP 17362 |
16.75 |
| 2026-06-15 12:00 |
03:43:00.95 |
+33:34:12.3 |
HIP 17362 |
14.73 |
| 2026-06-16 00:00 |
03:44:01.08 |
+33:37:56.1 |
HIP 17362 |
22.26 |
| 2026-06-16 12:00 |
03:45:01.23 |
+33:41:38.9 |
HIP 17571 |
10.48 |
| 2026-06-17 00:00 |
03:46:01.40 |
+33:45:20.5 |
HIP 17571 |
7.89 |
| 2026-06-17 12:00 |
03:47:01.59 |
+33:49:01.0 |
HIP 17622 |
6.86 |
| 2026-06-18 00:00 |
03:48:01.79 |
+33:52:40.5 |
HIP 17735 |
16.79 |
| 2026-06-18 12:00 |
03:49:02.01 |
+33:56:18.9 |
HIP 17969 |
19.49 |
| 2026-06-19 00:00 |
03:50:02.25 |
+33:59:56.1 |
HIP 17969 |
6.60 |
| 2026-06-19 12:00 |
03:51:02.50 |
+34:03:32.3 |
HIP 17969 |
6.73 |
| 2026-06-20 00:00 |
03:52:02.76 |
+34:07:07.4 |
HIP 18111 |
7.05 |
| 2026-06-20 12:00 |
03:53:03.04 |
+34:10:41.3 |
HIP 18111 |
9.49 |
| 2026-06-21 00:00 |
03:54:03.33 |
+34:14:14.2 |
HIP 18152 |
20.86 |
| 2026-06-21 12:00 |
03:55:03.64 |
+34:17:45.9 |
HIP 18394 |
11.04 |
| 2026-06-22 00:00 |
03:56:03.95 |
+34:21:16.6 |
HIP 18394 |
3.51 |