P/2021 R3 (PANSTARRS)
| 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
$$
M_a = (17.612 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.612 |
| n |
2.000 |
| gf |
0.906 |
| gb |
-0.732 |
| k |
0.996 |
| δ90 |
5.561 |
| 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) |
| 2026-02-03 00:00 |
10:22:04.64 |
-03:10:08.5 |
HIP 50748 |
29.05 |
| 2026-02-03 12:00 |
10:21:46.76 |
-03:10:02.9 |
HIP 50748 |
28.50 |
| 2026-02-04 00:00 |
10:21:28.76 |
-03:09:55.9 |
HIP 50748 |
28.62 |
| 2026-02-04 12:00 |
10:21:10.64 |
-03:09:47.6 |
HIP 50748 |
29.41 |
| 2026-02-05 00:00 |
10:20:52.41 |
-03:09:37.8 |
HIP 50748 |
30.85 |
| 2026-02-05 12:00 |
10:20:34.07 |
-03:09:26.7 |
HIP 50748 |
32.86 |
| 2026-02-06 00:00 |
10:20:15.61 |
-03:09:14.2 |
HIP 50748 |
35.35 |
| 2026-02-06 12:00 |
10:19:57.05 |
-03:09:00.4 |
HIP 50748 |
38.24 |
| 2026-02-07 00:00 |
10:19:38.39 |
-03:08:45.2 |
HIP 50404 |
39.26 |
| 2026-02-07 12:00 |
10:19:19.62 |
-03:08:28.7 |
HIP 50404 |
35.78 |
| 2026-02-08 00:00 |
10:19:00.76 |
-03:08:10.8 |
HIP 50404 |
32.60 |
| 2026-02-08 12:00 |
10:18:41.80 |
-03:07:51.5 |
HIP 50404 |
29.83 |
| 2026-02-09 00:00 |
10:18:22.75 |
-03:07:31.0 |
HIP 50404 |
27.62 |
| 2026-02-09 12:00 |
10:18:03.61 |
-03:07:09.1 |
HIP 50404 |
26.12 |
| 2026-02-10 00:00 |
10:17:44.38 |
-03:06:45.9 |
HIP 50343 |
23.76 |
| 2026-02-10 12:00 |
10:17:25.07 |
-03:06:21.5 |
HIP 50343 |
20.83 |
| 2026-02-11 00:00 |
10:17:05.69 |
-03:05:55.7 |
HIP 50343 |
18.68 |
| 2026-02-11 12:00 |
10:16:46.22 |
-03:05:28.6 |
HIP 50343 |
17.63 |
| 2026-02-12 00:00 |
10:16:26.68 |
-03:05:00.3 |
HIP 50343 |
17.87 |
| 2026-02-12 12:00 |
10:16:07.07 |
-03:04:30.6 |
HIP 50343 |
19.39 |
| 2026-02-13 00:00 |
10:15:47.40 |
-03:03:59.8 |
HIP 50187 |
19.82 |
| 2026-02-13 12:00 |
10:15:27.66 |
-03:03:27.6 |
HIP 50187 |
15.67 |
| 2026-02-14 00:00 |
10:15:07.86 |
-03:02:54.3 |
HIP 50187 |
12.13 |
| 2026-02-14 12:00 |
10:14:48.00 |
-03:02:19.7 |
HIP 50187 |
9.87 |
| 2026-02-15 00:00 |
10:14:28.09 |
-03:01:43.9 |
HIP 50187 |
9.87 |
| 2026-02-15 12:00 |
10:14:08.13 |
-03:01:06.9 |
HIP 50187 |
12.14 |
| 2026-02-16 00:00 |
10:13:48.13 |
-03:00:28.7 |
HIP 50187 |
15.74 |
| 2026-02-16 12:00 |
10:13:28.08 |
-02:59:49.3 |
HIP 50187 |
19.97 |
| 2026-02-17 00:00 |
10:13:08.00 |
-02:59:08.8 |
HIP 49969 |
24.12 |
| 2026-02-17 12:00 |
10:12:47.87 |
-02:58:27.1 |
HIP 49969 |
20.56 |
| 2026-02-18 00:00 |
10:12:27.72 |
-02:57:44.3 |
HIP 49969 |
17.73 |
| 2026-02-18 12:00 |
10:12:07.54 |
-02:57:00.3 |
HIP 49969 |
16.03 |
| 2026-02-19 00:00 |
10:11:47.33 |
-02:56:15.3 |
HIP 49969 |
15.84 |
| 2026-02-19 12:00 |
10:11:27.11 |
-02:55:29.1 |
HIP 49969 |
17.22 |
| 2026-02-20 00:00 |
10:11:06.86 |
-02:54:41.9 |
HIP 49818 |
17.15 |
| 2026-02-20 12:00 |
10:10:46.60 |
-02:53:53.6 |
HIP 49818 |
14.11 |
| 2026-02-21 00:00 |
10:10:26.33 |
-02:53:04.3 |
HIP 49818 |
12.53 |
| 2026-02-21 12:00 |
10:10:06.06 |
-02:52:13.9 |
HIP 49818 |
12.96 |
| 2026-02-22 00:00 |
10:09:45.78 |
-02:51:22.6 |
HIP 49818 |
15.23 |
| 2026-02-22 12:00 |
10:09:25.51 |
-02:50:30.2 |
HIP 49818 |
18.69 |
| 2026-02-23 00:00 |
10:09:05.24 |
-02:49:36.9 |
HIP 49818 |
22.80 |
| 2026-02-23 12:00 |
10:08:44.97 |
-02:48:42.6 |
HIP 49643 |
21.10 |
| 2026-02-24 00:00 |
10:08:24.72 |
-02:47:47.3 |
HIP 49643 |
17.84 |