| Parameter |
Value |
| Designation |
P/2021 R3 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-05-27T03:58:54.658560Z |
| Orbit solution date (soln_date, UTC) |
2021-11-20T19:13:08Z |
| Obs used |
63 |
| NEO |
- |
| M1 |
18.200 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-09-05T07:39:54.432000Z |
| Discovery magnitude (MPC) |
21.40 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-08-28.0000000 |
| e |
0.33193059 |
| q (au) |
2.525552 |
| a (au) |
3.780374 |
| i (deg) |
19.933099 |
| Ω (om, deg) |
304.252763 |
| ω (w, deg) |
3.018607 |
| M (ma, deg) |
12.448284 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.611 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.611 |
| n |
2.000 |
| gf |
0.906 |
| gb |
-0.732 |
| k |
0.996 |
| δ90 |
5.566 |
| 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) |
| 2026-09-20 00:00 |
11:18:08.10 |
-09:03:44.5 |
HIP 55139 |
14.63 |
| 2026-09-20 12:00 |
11:18:36.51 |
-09:07:25.7 |
HIP 55139 |
22.53 |
| 2026-09-21 00:00 |
11:19:04.93 |
-09:11:07.3 |
HIP 55364 |
25.50 |
| 2026-09-21 12:00 |
11:19:33.35 |
-09:14:49.4 |
HIP 55364 |
24.92 |
| 2026-09-22 00:00 |
11:20:01.77 |
-09:18:32.1 |
HIP 55395 |
24.24 |
| 2026-09-22 12:00 |
11:20:30.19 |
-09:22:15.2 |
HIP 55395 |
19.22 |
| 2026-09-23 00:00 |
11:20:58.61 |
-09:25:58.8 |
HIP 55395 |
16.63 |
| 2026-09-23 12:00 |
11:21:27.03 |
-09:29:42.9 |
HIP 55395 |
17.60 |
| 2026-09-24 00:00 |
11:21:55.45 |
-09:33:27.5 |
HIP 55395 |
21.64 |
| 2026-09-24 12:00 |
11:22:23.87 |
-09:37:12.6 |
HIP 55606 |
27.42 |
| 2026-09-25 00:00 |
11:22:52.29 |
-09:40:58.1 |
HIP 55606 |
27.34 |
| 2026-09-25 12:00 |
11:23:20.70 |
-09:44:44.1 |
HIP 55606 |
29.49 |
| 2026-09-26 00:00 |
11:23:49.11 |
-09:48:30.6 |
HIP 55606 |
33.46 |
| 2026-09-26 12:00 |
11:24:17.52 |
-09:52:17.6 |
HIP 55815 |
29.43 |
| 2026-09-27 00:00 |
11:24:45.93 |
-09:56:05.0 |
HIP 55815 |
22.66 |
| 2026-09-27 12:00 |
11:25:14.33 |
-09:59:52.9 |
HIP 55815 |
16.95 |
| 2026-09-28 00:00 |
11:25:42.73 |
-10:03:41.2 |
HIP 55815 |
13.72 |
| 2026-09-28 12:00 |
11:26:11.13 |
-10:07:30.1 |
HIP 55815 |
14.70 |
| 2026-09-29 00:00 |
11:26:39.52 |
-10:11:19.4 |
HIP 55857 |
15.20 |
| 2026-09-29 12:00 |
11:27:07.90 |
-10:15:09.1 |
HIP 55857 |
19.11 |
| 2026-09-30 00:00 |
11:27:36.28 |
-10:18:59.3 |
HIP 55857 |
25.03 |
| 2026-09-30 12:00 |
11:28:04.65 |
-10:22:49.9 |
HIP 56077 |
29.81 |
| 2026-10-01 00:00 |
11:28:33.02 |
-10:26:41.0 |
HIP 56077 |
27.91 |
| 2026-10-01 12:00 |
11:29:01.37 |
-10:30:32.6 |
HIP 56077 |
28.24 |
| 2026-10-02 00:00 |
11:29:29.73 |
-10:34:24.6 |
HIP 56077 |
30.72 |
| 2026-10-02 12:00 |
11:29:58.07 |
-10:38:17.0 |
HIP 56254 |
27.96 |
| 2026-10-03 00:00 |
11:30:26.40 |
-10:42:09.9 |
HIP 56254 |
21.94 |
| 2026-10-03 12:00 |
11:30:54.73 |
-10:46:03.2 |
HIP 56254 |
17.58 |
| 2026-10-04 00:00 |
11:31:23.04 |
-10:49:57.0 |
HIP 56254 |
16.24 |
| 2026-10-04 12:00 |
11:31:51.35 |
-10:53:51.2 |
HIP 56254 |
18.60 |
| 2026-10-05 00:00 |
11:32:19.64 |
-10:57:45.8 |
HIP 56254 |
23.57 |
| 2026-10-05 12:00 |
11:32:47.92 |
-11:01:40.8 |
HIP 56271 |
22.26 |
| 2026-10-06 00:00 |
11:33:16.19 |
-11:05:36.3 |
HIP 56271 |
23.09 |
| 2026-10-06 12:00 |
11:33:44.45 |
-11:09:32.1 |
HIP 56271 |
26.40 |
| 2026-10-07 00:00 |
11:34:12.69 |
-11:13:28.4 |
HIP 56271 |
31.43 |
| 2026-10-07 12:00 |
11:34:40.92 |
-11:17:25.1 |
HIP 56271 |
37.48 |
| 2026-10-08 00:00 |
11:35:09.14 |
-11:21:22.2 |
HIP 56494 |
44.02 |
| 2026-10-08 12:00 |
11:35:37.34 |
-11:25:19.8 |
HIP 56494 |
41.25 |
| 2026-10-09 00:00 |
11:36:05.52 |
-11:29:17.7 |
HIP 56494 |
39.89 |
| 2026-10-09 12:00 |
11:36:33.69 |
-11:33:16.0 |
HIP 56798 |
35.90 |
| 2026-10-10 00:00 |
11:37:01.84 |
-11:37:14.7 |
HIP 56798 |
32.88 |
| 2026-10-10 12:00 |
11:37:29.97 |
-11:41:13.8 |
HIP 56798 |
31.65 |
| 2026-10-11 00:00 |
11:37:58.08 |
-11:45:13.2 |
HIP 56824 |
26.99 |