| Parameter |
Value |
| Designation |
C/2021 P1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2022-06-01T16:41:49.732800Z |
| Orbit solution date (soln_date, UTC) |
2024-03-19T12:12:38Z |
| Obs used |
104 |
| NEO |
- |
| M1 |
12.700 |
| K1 |
7.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-08-04T13:25:21.792000Z |
| Discovery magnitude (MPC) |
21.20 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-09-13.0000000 |
| e |
1.00024450 |
| q (au) |
4.374954 |
| a (au) |
-17893.332037 |
| i (deg) |
51.622012 |
| Ω (om, deg) |
359.671523 |
| ω (w, deg) |
40.363907 |
| M (ma, deg) |
-0.000108 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.879 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.879 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.791 |
| k |
0.800 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
11:04:09.87 |
+33:02:08.8 |
HIP 54134 |
5.02 |
| 2026-07-29 12:00 |
11:04:19.04 |
+33:00:18.3 |
HIP 54134 |
2.55 |
| 2026-07-30 00:00 |
11:04:28.24 |
+32:58:28.1 |
HIP 54134 |
1.39 |
| 2026-07-30 12:00 |
11:04:37.49 |
+32:56:38.1 |
HIP 54134 |
3.40 |
| 2026-07-31 00:00 |
11:04:46.76 |
+32:54:48.3 |
HIP 54183 |
4.91 |
| 2026-07-31 12:00 |
11:04:56.08 |
+32:52:58.7 |
HIP 54183 |
2.26 |
| 2026-08-01 00:00 |
11:05:05.43 |
+32:51:09.4 |
HIP 54183 |
0.65 |
| 2026-08-01 12:00 |
11:05:14.82 |
+32:49:20.4 |
HIP 54183 |
3.18 |
| 2026-08-02 00:00 |
11:05:24.25 |
+32:47:31.6 |
HIP 54183 |
5.85 |
| 2026-08-02 12:00 |
11:05:33.71 |
+32:45:43.1 |
HIP 54183 |
8.54 |
| 2026-08-03 00:00 |
11:05:43.20 |
+32:43:54.8 |
HIP 54183 |
11.23 |
| 2026-08-03 12:00 |
11:05:52.73 |
+32:42:06.7 |
HIP 54183 |
13.92 |
| 2026-08-04 00:00 |
11:06:02.29 |
+32:40:19.0 |
HIP 54183 |
16.62 |
| 2026-08-04 12:00 |
11:06:11.89 |
+32:38:31.4 |
HIP 54183 |
19.32 |
| 2026-08-05 00:00 |
11:06:21.52 |
+32:36:44.2 |
HIP 54183 |
22.02 |
| 2026-08-05 12:00 |
11:06:31.18 |
+32:34:57.2 |
HIP 54403 |
23.01 |
| 2026-08-06 00:00 |
11:06:40.87 |
+32:33:10.5 |
HIP 54403 |
20.31 |
| 2026-08-06 12:00 |
11:06:50.59 |
+32:31:24.1 |
HIP 54403 |
17.61 |
| 2026-08-07 00:00 |
11:07:00.35 |
+32:29:37.9 |
HIP 54403 |
14.90 |
| 2026-08-07 12:00 |
11:07:10.13 |
+32:27:52.1 |
HIP 54403 |
12.20 |
| 2026-08-08 00:00 |
11:07:19.95 |
+32:26:06.5 |
HIP 54403 |
9.50 |
| 2026-08-08 12:00 |
11:07:29.79 |
+32:24:21.2 |
HIP 54403 |
6.82 |
| 2026-08-09 00:00 |
11:07:39.67 |
+32:22:36.2 |
HIP 54403 |
4.17 |
| 2026-08-09 12:00 |
11:07:49.57 |
+32:20:51.5 |
HIP 54403 |
1.75 |
| 2026-08-10 00:00 |
11:07:59.50 |
+32:19:07.0 |
HIP 54403 |
1.90 |
| 2026-08-10 12:00 |
11:08:09.46 |
+32:17:22.9 |
HIP 54403 |
4.36 |
| 2026-08-11 00:00 |
11:08:19.44 |
+32:15:39.1 |
HIP 54403 |
7.02 |
| 2026-08-11 12:00 |
11:08:29.45 |
+32:13:55.6 |
HIP 54403 |
9.71 |
| 2026-08-12 00:00 |
11:08:39.49 |
+32:12:12.4 |
HIP 54403 |
12.43 |
| 2026-08-12 12:00 |
11:08:49.55 |
+32:10:29.6 |
HIP 54403 |
15.15 |
| 2026-08-13 00:00 |
11:08:59.63 |
+32:08:47.0 |
HIP 54403 |
17.87 |
| 2026-08-13 12:00 |
11:09:09.74 |
+32:07:04.8 |
HIP 54403 |
20.60 |
| 2026-08-14 00:00 |
11:09:19.87 |
+32:05:22.9 |
HIP 54403 |
23.33 |
| 2026-08-14 12:00 |
11:09:30.03 |
+32:03:41.3 |
HIP 54403 |
26.06 |
| 2026-08-15 00:00 |
11:09:40.21 |
+32:02:00.0 |
HIP 54403 |
28.80 |
| 2026-08-15 12:00 |
11:09:50.41 |
+32:00:19.1 |
HIP 54403 |
31.53 |
| 2026-08-16 00:00 |
11:10:00.63 |
+31:58:38.5 |
HIP 54567 |
33.24 |
| 2026-08-16 12:00 |
11:10:10.87 |
+31:56:58.3 |
HIP 54567 |
35.04 |
| 2026-08-17 00:00 |
11:10:21.13 |
+31:55:18.4 |
HIP 54762 |
36.72 |
| 2026-08-17 12:00 |
11:10:31.41 |
+31:53:38.9 |
HIP 54762 |
33.98 |
| 2026-08-18 00:00 |
11:10:41.71 |
+31:51:59.7 |
HIP 54762 |
31.25 |
| 2026-08-18 12:00 |
11:10:52.02 |
+31:50:20.8 |
HIP 54762 |
28.51 |
| 2026-08-19 00:00 |
11:11:02.36 |
+31:48:42.4 |
HIP 54762 |
25.78 |