| 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) |
| 2026-07-29 00:00 |
10:29:53.60 |
-03:31:21.8 |
HIP 51302 |
21.81 |
| 2026-07-29 12:00 |
10:30:18.84 |
-03:33:52.0 |
HIP 51527 |
19.90 |
| 2026-07-30 00:00 |
10:30:44.14 |
-03:36:23.0 |
HIP 51527 |
13.29 |
| 2026-07-30 12:00 |
10:31:09.49 |
-03:38:54.8 |
HIP 51527 |
7.03 |
| 2026-07-31 00:00 |
10:31:34.90 |
-03:41:27.4 |
HIP 51527 |
3.85 |
| 2026-07-31 12:00 |
10:32:00.37 |
-03:44:00.8 |
HIP 51527 |
8.60 |
| 2026-08-01 00:00 |
10:32:25.90 |
-03:46:35.1 |
HIP 51527 |
15.07 |
| 2026-08-01 12:00 |
10:32:51.48 |
-03:49:10.1 |
HIP 51527 |
21.81 |
| 2026-08-02 00:00 |
10:33:17.11 |
-03:51:46.0 |
HIP 51745 |
18.55 |
| 2026-08-02 12:00 |
10:33:42.80 |
-03:54:22.6 |
HIP 51745 |
15.63 |
| 2026-08-03 00:00 |
10:34:08.55 |
-03:57:00.1 |
HIP 51784 |
10.83 |
| 2026-08-03 12:00 |
10:34:34.35 |
-03:59:38.4 |
HIP 51784 |
6.92 |
| 2026-08-04 00:00 |
10:35:00.20 |
-04:02:17.4 |
HIP 51784 |
8.70 |
| 2026-08-04 12:00 |
10:35:26.10 |
-04:04:57.3 |
HIP 51784 |
14.18 |
| 2026-08-05 00:00 |
10:35:52.06 |
-04:07:37.9 |
HIP 51784 |
20.61 |
| 2026-08-05 12:00 |
10:36:18.07 |
-04:10:19.3 |
HIP 51784 |
27.35 |
| 2026-08-06 00:00 |
10:36:44.13 |
-04:13:01.5 |
HIP 51864 |
27.61 |
| 2026-08-06 12:00 |
10:37:10.24 |
-04:15:44.6 |
HIP 51864 |
29.49 |
| 2026-08-07 00:00 |
10:37:36.40 |
-04:18:28.3 |
HIP 51864 |
32.81 |
| 2026-08-07 12:00 |
10:38:02.61 |
-04:21:12.9 |
HIP 51930 |
36.71 |
| 2026-08-08 00:00 |
10:38:28.87 |
-04:23:58.3 |
HIP 51930 |
39.28 |
| 2026-08-08 12:00 |
10:38:55.18 |
-04:26:44.4 |
HIP 51930 |
42.89 |
| 2026-08-09 00:00 |
10:39:21.53 |
-04:29:31.3 |
HIP 52349 |
45.72 |
| 2026-08-09 12:00 |
10:39:47.94 |
-04:32:19.0 |
HIP 52349 |
42.16 |
| 2026-08-10 00:00 |
10:40:14.38 |
-04:35:07.4 |
HIP 52349 |
39.60 |
| 2026-08-10 12:00 |
10:40:40.88 |
-04:37:56.6 |
HIP 52424 |
37.96 |
| 2026-08-11 00:00 |
10:41:07.42 |
-04:40:46.6 |
HIP 52424 |
33.16 |
| 2026-08-11 12:00 |
10:41:34.01 |
-04:43:37.3 |
HIP 52424 |
29.37 |
| 2026-08-12 00:00 |
10:42:00.64 |
-04:46:28.8 |
HIP 52424 |
27.01 |
| 2026-08-12 12:00 |
10:42:27.31 |
-04:49:21.0 |
HIP 52424 |
26.48 |
| 2026-08-13 00:00 |
10:42:54.03 |
-04:52:14.0 |
HIP 52424 |
27.90 |
| 2026-08-13 12:00 |
10:43:20.78 |
-04:55:07.8 |
HIP 52424 |
31.01 |
| 2026-08-14 00:00 |
10:43:47.58 |
-04:58:02.2 |
HIP 52424 |
35.38 |
| 2026-08-14 12:00 |
10:44:14.42 |
-05:00:57.4 |
HIP 52424 |
40.61 |
| 2026-08-15 00:00 |
10:44:41.30 |
-05:03:53.4 |
HIP 52731 |
36.96 |
| 2026-08-15 12:00 |
10:45:08.22 |
-05:06:50.1 |
HIP 52731 |
29.71 |
| 2026-08-16 00:00 |
10:45:35.18 |
-05:09:47.5 |
HIP 52731 |
22.49 |
| 2026-08-16 12:00 |
10:46:02.18 |
-05:12:45.6 |
HIP 52731 |
15.37 |
| 2026-08-17 00:00 |
10:46:29.21 |
-05:15:44.4 |
HIP 52731 |
8.63 |
| 2026-08-17 12:00 |
10:46:56.28 |
-05:18:44.0 |
HIP 52731 |
4.57 |
| 2026-08-18 00:00 |
10:47:23.39 |
-05:21:44.2 |
HIP 52731 |
8.73 |
| 2026-08-18 12:00 |
10:47:50.53 |
-05:24:45.2 |
HIP 52731 |
15.52 |
| 2026-08-19 00:00 |
10:48:17.71 |
-05:27:46.9 |
HIP 52899 |
13.25 |