| Parameter |
Value |
| Designation |
400P/PANSTARRS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-02-09T22:37:16.553280Z |
| Orbit solution date (soln_date, UTC) |
2024-10-05T23:12:48Z |
| Obs used |
414 |
| NEO |
- |
| M1 |
13.800 |
| K1 |
12.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2020-09-10T09:07:24.096000Z |
| Discovery magnitude (MPC) |
19.20 G |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2020-02-27.0000000 |
| e |
0.40901297 |
| q (au) |
2.104108 |
| a (au) |
3.560329 |
| i (deg) |
10.926393 |
| Ω (om, deg) |
176.405371 |
| ω (w, deg) |
238.711384 |
| M (ma, deg) |
308.805563 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.776 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.776 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2020-06-01 |
2020-08-29 |
+19.2128 |
-6.748 |
| 2020-08-29 |
2021-02-07 |
+8.6813 |
-3.045 |
| 2021-02-10 |
2022-02-24 |
+1.7883 |
-1.680 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
20:22:39.58 |
-07:15:39.5 |
HIP 100596 |
27.35 |
| 2026-06-01 12:00 |
20:22:36.21 |
-07:14:45.3 |
HIP 100596 |
28.58 |
| 2026-06-02 00:00 |
20:22:32.58 |
-07:13:52.2 |
HIP 100596 |
29.84 |
| 2026-06-02 12:00 |
20:22:28.69 |
-07:13:00.3 |
HIP 100596 |
31.13 |
| 2026-06-03 00:00 |
20:22:24.54 |
-07:12:09.5 |
HIP 100596 |
32.46 |
| 2026-06-03 12:00 |
20:22:20.14 |
-07:11:19.9 |
HIP 100596 |
33.81 |
| 2026-06-04 00:00 |
20:22:15.48 |
-07:10:31.6 |
HIP 100596 |
35.19 |
| 2026-06-04 12:00 |
20:22:10.56 |
-07:09:44.4 |
HIP 100427 |
35.96 |
| 2026-06-05 00:00 |
20:22:05.38 |
-07:08:58.4 |
HIP 100427 |
35.08 |
| 2026-06-05 12:00 |
20:21:59.94 |
-07:08:13.7 |
HIP 100427 |
34.25 |
| 2026-06-06 00:00 |
20:21:54.25 |
-07:07:30.2 |
HIP 100427 |
33.50 |
| 2026-06-06 12:00 |
20:21:48.29 |
-07:06:48.0 |
HIP 100427 |
32.83 |
| 2026-06-07 00:00 |
20:21:42.08 |
-07:06:07.0 |
HIP 100427 |
32.25 |
| 2026-06-07 12:00 |
20:21:35.61 |
-07:05:27.4 |
HIP 100427 |
31.79 |
| 2026-06-08 00:00 |
20:21:28.88 |
-07:04:48.9 |
HIP 100427 |
31.45 |
| 2026-06-08 12:00 |
20:21:21.89 |
-07:04:11.8 |
HIP 100427 |
31.24 |
| 2026-06-09 00:00 |
20:21:14.64 |
-07:03:36.0 |
HIP 100427 |
31.19 |
| 2026-06-09 12:00 |
20:21:07.14 |
-07:03:01.5 |
HIP 100427 |
31.29 |
| 2026-06-10 00:00 |
20:20:59.38 |
-07:02:28.4 |
HIP 100427 |
31.56 |
| 2026-06-10 12:00 |
20:20:51.35 |
-07:01:56.6 |
HIP 100427 |
32.00 |
| 2026-06-11 00:00 |
20:20:43.08 |
-07:01:26.1 |
HIP 100427 |
32.63 |
| 2026-06-11 12:00 |
20:20:34.54 |
-07:00:57.0 |
HIP 100153 |
33.24 |
| 2026-06-12 00:00 |
20:20:25.75 |
-07:00:29.3 |
HIP 100153 |
31.34 |
| 2026-06-12 12:00 |
20:20:16.70 |
-07:00:02.9 |
HIP 100153 |
29.47 |
| 2026-06-13 00:00 |
20:20:07.40 |
-06:59:38.0 |
HIP 100153 |
27.65 |
| 2026-06-13 12:00 |
20:19:57.85 |
-06:59:14.4 |
HIP 100153 |
25.88 |
| 2026-06-14 00:00 |
20:19:48.04 |
-06:58:52.3 |
HIP 100153 |
24.21 |
| 2026-06-14 12:00 |
20:19:37.97 |
-06:58:31.6 |
HIP 100153 |
22.69 |
| 2026-06-15 00:00 |
20:19:27.66 |
-06:58:12.3 |
HIP 100153 |
21.34 |
| 2026-06-15 12:00 |
20:19:17.10 |
-06:57:54.4 |
HIP 100153 |
20.25 |
| 2026-06-16 00:00 |
20:19:06.28 |
-06:57:38.0 |
HIP 100153 |
19.48 |
| 2026-06-16 12:00 |
20:18:55.22 |
-06:57:23.0 |
HIP 100153 |
19.08 |
| 2026-06-17 00:00 |
20:18:43.91 |
-06:57:09.5 |
HIP 100153 |
19.11 |
| 2026-06-17 12:00 |
20:18:32.36 |
-06:56:57.5 |
HIP 100153 |
19.59 |
| 2026-06-18 00:00 |
20:18:20.56 |
-06:56:46.9 |
HIP 100153 |
20.52 |
| 2026-06-18 12:00 |
20:18:08.52 |
-06:56:37.8 |
HIP 99962 |
19.77 |
| 2026-06-19 00:00 |
20:17:56.24 |
-06:56:30.2 |
HIP 99962 |
16.86 |
| 2026-06-19 12:00 |
20:17:43.72 |
-06:56:24.1 |
HIP 99962 |
13.98 |
| 2026-06-20 00:00 |
20:17:30.97 |
-06:56:19.5 |
HIP 99962 |
11.18 |
| 2026-06-20 12:00 |
20:17:17.98 |
-06:56:16.3 |
HIP 99962 |
8.61 |
| 2026-06-21 00:00 |
20:17:04.75 |
-06:56:14.7 |
HIP 99962 |
6.65 |
| 2026-06-21 12:00 |
20:16:51.29 |
-06:56:14.6 |
HIP 99962 |
6.00 |
| 2026-06-22 00:00 |
20:16:37.60 |
-06:56:15.9 |
HIP 99962 |
7.14 |