| Parameter |
Value |
| Designation |
C/2021 Q6 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2024-03-23T13:47:29.414400Z |
| Orbit solution date (soln_date, UTC) |
2025-09-16T12:42:41Z |
| Obs used |
388 |
| NEO |
- |
| M1 |
5.000 |
| K1 |
10.750 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-08-22T12:28:12.316800Z |
| Discovery magnitude (MPC) |
22.25 z |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-03-12.0000000 |
| e |
0.99972188 |
| q (au) |
8.709141 |
| a (au) |
31314.293105 |
| i (deg) |
161.847387 |
| Ω (om, deg) |
133.533757 |
| ω (w, deg) |
140.936211 |
| M (ma, deg) |
359.999933 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.902 + 4.541\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.902 |
| n |
4.541 |
| gf |
0.875 |
| gb |
-0.776 |
| k |
0.823 |
| δ90 |
6.898 |
| 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 |
21:23:00.91 |
-15:38:10.1 |
HIP 105474 |
26.93 |
| 2026-06-01 12:00 |
21:22:51.79 |
-15:39:19.9 |
HIP 105474 |
24.64 |
| 2026-06-02 00:00 |
21:22:42.56 |
-15:40:30.2 |
HIP 105474 |
22.37 |
| 2026-06-02 12:00 |
21:22:33.22 |
-15:41:40.9 |
HIP 105474 |
20.12 |
| 2026-06-03 00:00 |
21:22:23.77 |
-15:42:52.2 |
HIP 105474 |
17.94 |
| 2026-06-03 12:00 |
21:22:14.20 |
-15:44:04.1 |
HIP 105474 |
15.86 |
| 2026-06-04 00:00 |
21:22:04.53 |
-15:45:16.4 |
HIP 105474 |
13.93 |
| 2026-06-04 12:00 |
21:21:54.75 |
-15:46:29.2 |
HIP 105474 |
12.25 |
| 2026-06-05 00:00 |
21:21:44.86 |
-15:47:42.6 |
HIP 105474 |
10.95 |
| 2026-06-05 12:00 |
21:21:34.86 |
-15:48:56.4 |
HIP 105474 |
10.20 |
| 2026-06-06 00:00 |
21:21:24.75 |
-15:50:10.8 |
HIP 105474 |
10.14 |
| 2026-06-06 12:00 |
21:21:14.53 |
-15:51:25.6 |
HIP 105474 |
10.81 |
| 2026-06-07 00:00 |
21:21:04.20 |
-15:52:41.0 |
HIP 105474 |
12.11 |
| 2026-06-07 12:00 |
21:20:53.76 |
-15:53:56.9 |
HIP 105474 |
13.87 |
| 2026-06-08 00:00 |
21:20:43.22 |
-15:55:13.2 |
HIP 105474 |
15.96 |
| 2026-06-08 12:00 |
21:20:32.56 |
-15:56:30.1 |
HIP 105474 |
18.28 |
| 2026-06-09 00:00 |
21:20:21.80 |
-15:57:47.4 |
HIP 105256 |
20.65 |
| 2026-06-09 12:00 |
21:20:10.93 |
-15:59:05.2 |
HIP 105256 |
17.82 |
| 2026-06-10 00:00 |
21:19:59.95 |
-16:00:23.5 |
HIP 105256 |
14.99 |
| 2026-06-10 12:00 |
21:19:48.86 |
-16:01:42.3 |
HIP 105256 |
12.19 |
| 2026-06-11 00:00 |
21:19:37.67 |
-16:03:01.5 |
HIP 105256 |
9.47 |
| 2026-06-11 12:00 |
21:19:26.37 |
-16:04:21.3 |
HIP 105256 |
6.98 |
| 2026-06-12 00:00 |
21:19:14.96 |
-16:05:41.5 |
HIP 105256 |
5.08 |
| 2026-06-12 12:00 |
21:19:03.45 |
-16:07:02.1 |
HIP 105256 |
4.64 |
| 2026-06-13 00:00 |
21:18:51.83 |
-16:08:23.3 |
HIP 105256 |
6.04 |
| 2026-06-13 12:00 |
21:18:40.11 |
-16:09:44.9 |
HIP 105256 |
8.42 |
| 2026-06-14 00:00 |
21:18:28.28 |
-16:11:06.9 |
HIP 105256 |
11.21 |
| 2026-06-14 12:00 |
21:18:16.34 |
-16:12:29.4 |
HIP 105256 |
14.17 |
| 2026-06-15 00:00 |
21:18:04.31 |
-16:13:52.4 |
HIP 105256 |
17.24 |
| 2026-06-15 12:00 |
21:17:52.17 |
-16:15:15.8 |
HIP 105256 |
20.37 |
| 2026-06-16 00:00 |
21:17:39.92 |
-16:16:39.6 |
HIP 105131 |
23.37 |
| 2026-06-16 12:00 |
21:17:27.58 |
-16:18:03.9 |
HIP 105131 |
25.27 |
| 2026-06-17 00:00 |
21:17:15.13 |
-16:19:28.6 |
HIP 105131 |
27.45 |
| 2026-06-17 12:00 |
21:17:02.58 |
-16:20:53.7 |
HIP 104956 |
26.09 |
| 2026-06-18 00:00 |
21:16:49.93 |
-16:22:19.3 |
HIP 104956 |
24.66 |
| 2026-06-18 12:00 |
21:16:37.18 |
-16:23:45.3 |
HIP 104956 |
23.61 |
| 2026-06-19 00:00 |
21:16:24.33 |
-16:25:11.6 |
HIP 104956 |
23.01 |
| 2026-06-19 12:00 |
21:16:11.38 |
-16:26:38.4 |
HIP 104956 |
22.91 |
| 2026-06-20 00:00 |
21:15:58.34 |
-16:28:05.6 |
HIP 104956 |
23.31 |
| 2026-06-20 12:00 |
21:15:45.19 |
-16:29:33.2 |
HIP 104956 |
24.21 |
| 2026-06-21 00:00 |
21:15:31.95 |
-16:31:01.2 |
HIP 104956 |
25.56 |
| 2026-06-21 12:00 |
21:15:18.62 |
-16:32:29.5 |
HIP 104956 |
27.31 |
| 2026-06-22 00:00 |
21:15:05.19 |
-16:33:58.3 |
HIP 104956 |
29.38 |