| Parameter |
Value |
| Designation |
C/2021 J2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-09-22T11:24:15.621120Z |
| Orbit solution date (soln_date, UTC) |
2023-12-06T01:14:09Z |
| Obs used |
218 |
| NEO |
- |
| M1 |
13.600 |
| K1 |
4.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-05-10T09:49:17.990400Z |
| Discovery magnitude (MPC) |
22.06 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2022-02-01.0000000 |
| e |
0.95985091 |
| q (au) |
4.706567 |
| a (au) |
117.227257 |
| i (deg) |
156.209020 |
| Ω (om, deg) |
23.329370 |
| ω (w, deg) |
172.059356 |
| M (ma, deg) |
0.102134 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.688 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.688 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.612 |
| 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) |
| 2026-06-01 00:00 |
06:45:27.64 |
+00:51:23.9 |
HIP 32327 |
16.52 |
| 2026-06-01 12:00 |
06:45:33.17 |
+00:51:45.0 |
HIP 32327 |
17.56 |
| 2026-06-02 00:00 |
06:45:38.73 |
+00:52:05.7 |
HIP 32327 |
18.65 |
| 2026-06-02 12:00 |
06:45:44.32 |
+00:52:26.0 |
HIP 32327 |
19.78 |
| 2026-06-03 00:00 |
06:45:49.94 |
+00:52:45.9 |
HIP 32327 |
20.95 |
| 2026-06-03 12:00 |
06:45:55.59 |
+00:53:05.3 |
HIP 32327 |
22.15 |
| 2026-06-04 00:00 |
06:46:01.27 |
+00:53:24.3 |
HIP 32327 |
23.38 |
| 2026-06-04 12:00 |
06:46:06.98 |
+00:53:42.9 |
HIP 32327 |
24.64 |
| 2026-06-05 00:00 |
06:46:12.72 |
+00:54:01.0 |
HIP 32327 |
25.91 |
| 2026-06-05 12:00 |
06:46:18.48 |
+00:54:18.7 |
HIP 32586 |
25.88 |
| 2026-06-06 00:00 |
06:46:24.28 |
+00:54:36.0 |
HIP 32586 |
24.59 |
| 2026-06-06 12:00 |
06:46:30.10 |
+00:54:52.9 |
HIP 32586 |
23.32 |
| 2026-06-07 00:00 |
06:46:35.94 |
+00:55:09.3 |
HIP 32586 |
22.07 |
| 2026-06-07 12:00 |
06:46:41.81 |
+00:55:25.3 |
HIP 32586 |
20.84 |
| 2026-06-08 00:00 |
06:46:47.71 |
+00:55:40.9 |
HIP 32586 |
19.63 |
| 2026-06-08 12:00 |
06:46:53.63 |
+00:55:56.0 |
HIP 32586 |
18.46 |
| 2026-06-09 00:00 |
06:46:59.58 |
+00:56:10.7 |
HIP 32586 |
17.33 |
| 2026-06-09 12:00 |
06:47:05.55 |
+00:56:25.0 |
HIP 32586 |
16.25 |
| 2026-06-10 00:00 |
06:47:11.54 |
+00:56:38.8 |
HIP 32586 |
15.24 |
| 2026-06-10 12:00 |
06:47:17.56 |
+00:56:52.3 |
HIP 32586 |
14.31 |
| 2026-06-11 00:00 |
06:47:23.60 |
+00:57:05.2 |
HIP 32586 |
13.47 |
| 2026-06-11 12:00 |
06:47:29.66 |
+00:57:17.8 |
HIP 32586 |
12.76 |
| 2026-06-12 00:00 |
06:47:35.74 |
+00:57:29.9 |
HIP 32586 |
12.18 |
| 2026-06-12 12:00 |
06:47:41.84 |
+00:57:41.6 |
HIP 32586 |
11.78 |
| 2026-06-13 00:00 |
06:47:47.96 |
+00:57:52.9 |
HIP 32586 |
11.55 |
| 2026-06-13 12:00 |
06:47:54.10 |
+00:58:03.7 |
HIP 32586 |
11.52 |
| 2026-06-14 00:00 |
06:48:00.26 |
+00:58:14.1 |
HIP 32586 |
11.69 |
| 2026-06-14 12:00 |
06:48:06.44 |
+00:58:24.0 |
HIP 32586 |
12.05 |
| 2026-06-15 00:00 |
06:48:12.64 |
+00:58:33.6 |
HIP 32586 |
12.59 |
| 2026-06-15 12:00 |
06:48:18.86 |
+00:58:42.7 |
HIP 32682 |
11.29 |
| 2026-06-16 00:00 |
06:48:25.09 |
+00:58:51.3 |
HIP 32682 |
9.72 |
| 2026-06-16 12:00 |
06:48:31.33 |
+00:58:59.6 |
HIP 32682 |
8.16 |
| 2026-06-17 00:00 |
06:48:37.60 |
+00:59:07.4 |
HIP 32682 |
6.59 |
| 2026-06-17 12:00 |
06:48:43.88 |
+00:59:14.8 |
HIP 32682 |
5.02 |
| 2026-06-18 00:00 |
06:48:50.17 |
+00:59:21.7 |
HIP 32682 |
3.46 |
| 2026-06-18 12:00 |
06:48:56.47 |
+00:59:28.2 |
HIP 32682 |
1.91 |
| 2026-06-19 00:00 |
06:49:02.79 |
+00:59:34.3 |
HIP 32682 |
0.59 |
| 2026-06-19 12:00 |
06:49:09.13 |
+00:59:40.0 |
HIP 32682 |
1.44 |
| 2026-06-20 00:00 |
06:49:15.47 |
+00:59:45.2 |
HIP 32682 |
2.98 |
| 2026-06-20 12:00 |
06:49:21.83 |
+00:59:50.0 |
HIP 32682 |
4.55 |
| 2026-06-21 00:00 |
06:49:28.19 |
+00:59:54.4 |
HIP 32682 |
6.14 |
| 2026-06-21 12:00 |
06:49:34.57 |
+00:59:58.4 |
HIP 32682 |
7.73 |
| 2026-06-22 00:00 |
06:49:40.96 |
+01:00:01.9 |
HIP 32682 |
9.32 |