| 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 |
0.999 |
| 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) |
| 2026-03-26 00:00 |
01:09:26.20 |
+20:23:48.9 |
HIP 5285 |
27.56 |
| 2026-03-26 12:00 |
01:10:18.14 |
+20:29:19.0 |
HIP 5667 |
35.10 |
| 2026-03-27 00:00 |
01:11:10.15 |
+20:34:49.0 |
HIP 5667 |
23.39 |
| 2026-03-27 12:00 |
01:12:02.21 |
+20:40:18.8 |
HIP 5667 |
14.81 |
| 2026-03-28 00:00 |
01:12:54.34 |
+20:45:48.6 |
HIP 5667 |
15.79 |
| 2026-03-28 12:00 |
01:13:46.53 |
+20:51:18.2 |
HIP 5774 |
17.16 |
| 2026-03-29 00:00 |
01:14:38.78 |
+20:56:47.7 |
HIP 5774 |
23.39 |
| 2026-03-29 12:00 |
01:15:31.10 |
+21:02:17.0 |
HIP 5977 |
18.51 |
| 2026-03-30 00:00 |
01:16:23.48 |
+21:07:46.1 |
HIP 5977 |
7.80 |
| 2026-03-30 12:00 |
01:17:15.92 |
+21:13:15.1 |
HIP 5977 |
11.76 |
| 2026-03-31 00:00 |
01:18:08.42 |
+21:18:44.0 |
HIP 6219 |
22.32 |
| 2026-03-31 12:00 |
01:19:00.98 |
+21:24:12.6 |
HIP 6219 |
12.64 |
| 2026-04-01 00:00 |
01:19:53.61 |
+21:29:41.1 |
HIP 6219 |
13.47 |
| 2026-04-01 12:00 |
01:20:46.29 |
+21:35:09.4 |
HIP 6301 |
8.68 |
| 2026-04-02 00:00 |
01:21:39.05 |
+21:40:37.5 |
HIP 6301 |
11.28 |
| 2026-04-02 12:00 |
01:22:31.86 |
+21:46:05.4 |
HIP 6301 |
23.22 |
| 2026-04-03 00:00 |
01:23:24.73 |
+21:51:33.0 |
HIP 6554 |
11.36 |
| 2026-04-03 12:00 |
01:24:17.67 |
+21:57:00.5 |
HIP 6554 |
5.60 |
| 2026-04-04 00:00 |
01:25:10.67 |
+22:02:27.7 |
HIP 6577 |
9.26 |
| 2026-04-04 12:00 |
01:26:03.74 |
+22:07:54.7 |
HIP 6577 |
22.27 |
| 2026-04-05 00:00 |
01:26:56.86 |
+22:13:21.5 |
HIP 6808 |
32.19 |
| 2026-04-05 12:00 |
01:27:50.05 |
+22:18:48.0 |
HIP 7001 |
31.70 |
| 2026-04-06 00:00 |
01:28:43.30 |
+22:24:14.3 |
HIP 7001 |
19.59 |
| 2026-04-06 12:00 |
01:29:36.61 |
+22:29:40.3 |
HIP 7001 |
11.21 |
| 2026-04-07 00:00 |
01:30:29.99 |
+22:35:06.1 |
HIP 7001 |
15.18 |
| 2026-04-07 12:00 |
01:31:23.43 |
+22:40:31.6 |
HIP 7119 |
6.25 |
| 2026-04-08 00:00 |
01:32:16.93 |
+22:45:56.8 |
HIP 7119 |
7.63 |
| 2026-04-08 12:00 |
01:33:10.50 |
+22:51:21.7 |
HIP 7119 |
20.99 |
| 2026-04-09 00:00 |
01:34:04.12 |
+22:56:46.4 |
HIP 7390 |
18.35 |
| 2026-04-09 12:00 |
01:34:57.81 |
+23:02:10.7 |
HIP 7390 |
4.90 |
| 2026-04-10 00:00 |
01:35:51.56 |
+23:07:34.7 |
HIP 7390 |
8.68 |
| 2026-04-10 12:00 |
01:36:45.38 |
+23:12:58.5 |
HIP 7570 |
15.32 |
| 2026-04-11 00:00 |
01:37:39.26 |
+23:18:21.9 |
HIP 7570 |
16.48 |
| 2026-04-11 12:00 |
01:38:33.19 |
+23:23:45.0 |
HIP 7570 |
25.95 |
| 2026-04-12 00:00 |
01:39:27.20 |
+23:29:07.7 |
HIP 7768 |
17.26 |
| 2026-04-12 12:00 |
01:40:21.26 |
+23:34:30.1 |
HIP 7768 |
11.31 |
| 2026-04-13 00:00 |
01:41:15.38 |
+23:39:52.2 |
HIP 7768 |
17.96 |
| 2026-04-13 12:00 |
01:42:09.57 |
+23:45:13.9 |
HIP 7889 |
27.40 |
| 2026-04-14 00:00 |
01:43:03.82 |
+23:50:35.2 |
HIP 8146 |
23.16 |
| 2026-04-14 12:00 |
01:43:58.13 |
+23:55:56.2 |
HIP 8146 |
11.78 |
| 2026-04-15 00:00 |
01:44:52.50 |
+24:01:16.8 |
HIP 8146 |
10.34 |
| 2026-04-15 12:00 |
01:45:46.94 |
+24:06:37.0 |
HIP 8146 |
21.00 |
| 2026-04-16 00:00 |
01:46:41.43 |
+24:11:56.9 |
HIP 8311 |
13.43 |