| 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) |
| 2026-09-20 00:00 |
19:29:42.82 |
-11:54:00.6 |
HIP 95949 |
15.25 |
| 2026-09-20 12:00 |
19:29:44.73 |
-11:55:56.3 |
HIP 95949 |
15.22 |
| 2026-09-21 00:00 |
19:29:46.95 |
-11:57:51.3 |
HIP 95949 |
15.38 |
| 2026-09-21 12:00 |
19:29:49.49 |
-11:59:45.5 |
HIP 95949 |
15.71 |
| 2026-09-22 00:00 |
19:29:52.34 |
-12:01:38.9 |
HIP 95949 |
16.22 |
| 2026-09-22 12:00 |
19:29:55.50 |
-12:03:31.6 |
HIP 95949 |
16.89 |
| 2026-09-23 00:00 |
19:29:58.97 |
-12:05:23.6 |
HIP 95949 |
17.71 |
| 2026-09-23 12:00 |
19:30:02.75 |
-12:07:14.7 |
HIP 95949 |
18.67 |
| 2026-09-24 00:00 |
19:30:06.85 |
-12:09:05.1 |
HIP 95949 |
19.75 |
| 2026-09-24 12:00 |
19:30:11.25 |
-12:10:54.6 |
HIP 95949 |
20.94 |
| 2026-09-25 00:00 |
19:30:15.96 |
-12:12:43.4 |
HIP 95949 |
22.24 |
| 2026-09-25 12:00 |
19:30:20.98 |
-12:14:31.3 |
HIP 95883 |
20.82 |
| 2026-09-26 00:00 |
19:30:26.31 |
-12:16:18.4 |
HIP 95883 |
19.44 |
| 2026-09-26 12:00 |
19:30:31.95 |
-12:18:04.7 |
HIP 95883 |
18.27 |
| 2026-09-27 00:00 |
19:30:37.89 |
-12:19:50.1 |
HIP 95883 |
17.35 |
| 2026-09-27 12:00 |
19:30:44.14 |
-12:21:34.8 |
HIP 95883 |
16.76 |
| 2026-09-28 00:00 |
19:30:50.70 |
-12:23:18.5 |
HIP 95883 |
16.54 |
| 2026-09-28 12:00 |
19:30:57.56 |
-12:25:01.4 |
HIP 95883 |
16.72 |
| 2026-09-29 00:00 |
19:31:04.72 |
-12:26:43.5 |
HIP 95883 |
17.31 |
| 2026-09-29 12:00 |
19:31:12.18 |
-12:28:24.6 |
HIP 95883 |
18.28 |
| 2026-09-30 00:00 |
19:31:19.95 |
-12:30:04.9 |
HIP 95883 |
19.60 |
| 2026-09-30 12:00 |
19:31:28.02 |
-12:31:44.3 |
HIP 95883 |
21.21 |
| 2026-10-01 00:00 |
19:31:36.39 |
-12:33:22.8 |
HIP 95883 |
23.07 |
| 2026-10-01 12:00 |
19:31:45.06 |
-12:35:00.4 |
HIP 95883 |
25.14 |
| 2026-10-02 00:00 |
19:31:54.04 |
-12:36:37.2 |
HIP 95883 |
27.38 |
| 2026-10-02 12:00 |
19:32:03.31 |
-12:38:12.9 |
HIP 95883 |
29.78 |
| 2026-10-03 00:00 |
19:32:12.87 |
-12:39:47.8 |
HIP 95883 |
32.30 |
| 2026-10-03 12:00 |
19:32:22.74 |
-12:41:21.8 |
HIP 96265 |
33.27 |
| 2026-10-04 00:00 |
19:32:32.90 |
-12:42:54.8 |
HIP 96265 |
30.37 |
| 2026-10-04 12:00 |
19:32:43.36 |
-12:44:26.8 |
HIP 96265 |
27.41 |
| 2026-10-05 00:00 |
19:32:54.12 |
-12:45:58.0 |
HIP 96265 |
24.40 |
| 2026-10-05 12:00 |
19:33:05.17 |
-12:47:28.1 |
HIP 96265 |
21.34 |
| 2026-10-06 00:00 |
19:33:16.51 |
-12:48:57.3 |
HIP 96265 |
18.22 |
| 2026-10-06 12:00 |
19:33:28.15 |
-12:50:25.5 |
HIP 96265 |
15.04 |
| 2026-10-07 00:00 |
19:33:40.08 |
-12:51:52.8 |
HIP 96265 |
11.82 |
| 2026-10-07 12:00 |
19:33:52.30 |
-12:53:19.0 |
HIP 96265 |
8.55 |
| 2026-10-08 00:00 |
19:34:04.81 |
-12:54:44.3 |
HIP 96265 |
5.26 |
| 2026-10-08 12:00 |
19:34:17.61 |
-12:56:08.5 |
HIP 96265 |
2.15 |
| 2026-10-09 00:00 |
19:34:30.70 |
-12:57:31.8 |
HIP 96265 |
2.24 |
| 2026-10-09 12:00 |
19:34:44.08 |
-12:58:54.0 |
HIP 96265 |
5.49 |
| 2026-10-10 00:00 |
19:34:57.75 |
-13:00:15.2 |
HIP 96265 |
9.01 |
| 2026-10-10 12:00 |
19:35:11.70 |
-13:01:35.4 |
HIP 96265 |
12.62 |
| 2026-10-11 00:00 |
19:35:25.93 |
-13:02:54.5 |
HIP 96265 |
16.31 |