| 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 · 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) |
| 2026-03-26 00:00 |
19:56:38.48 |
-10:56:36.7 |
HIP 98059 |
16.51 |
| 2026-03-26 12:00 |
19:57:01.89 |
-10:54:43.2 |
HIP 98059 |
20.92 |
| 2026-03-27 00:00 |
19:57:25.18 |
-10:52:49.6 |
HIP 98059 |
25.97 |
| 2026-03-27 12:00 |
19:57:48.33 |
-10:50:55.8 |
HIP 98059 |
31.34 |
| 2026-03-28 00:00 |
19:58:11.34 |
-10:49:01.9 |
HIP 98344 |
30.10 |
| 2026-03-28 12:00 |
19:58:34.23 |
-10:47:07.9 |
HIP 98344 |
26.87 |
| 2026-03-29 00:00 |
19:58:56.98 |
-10:45:13.8 |
HIP 98344 |
24.66 |
| 2026-03-29 12:00 |
19:59:19.60 |
-10:43:19.5 |
HIP 98344 |
23.73 |
| 2026-03-30 00:00 |
19:59:42.08 |
-10:41:25.1 |
HIP 98564 |
23.56 |
| 2026-03-30 12:00 |
20:00:04.42 |
-10:39:30.7 |
HIP 98564 |
18.92 |
| 2026-03-31 00:00 |
20:00:26.63 |
-10:37:36.1 |
HIP 98564 |
15.15 |
| 2026-03-31 12:00 |
20:00:48.69 |
-10:35:41.4 |
HIP 98564 |
12.96 |
| 2026-04-01 00:00 |
20:01:10.62 |
-10:33:46.7 |
HIP 98564 |
13.14 |
| 2026-04-01 12:00 |
20:01:32.41 |
-10:31:51.9 |
HIP 98569 |
12.52 |
| 2026-04-02 00:00 |
20:01:54.05 |
-10:29:57.0 |
HIP 98569 |
13.39 |
| 2026-04-02 12:00 |
20:02:15.56 |
-10:28:02.1 |
HIP 98569 |
16.27 |
| 2026-04-03 00:00 |
20:02:36.92 |
-10:26:07.1 |
HIP 98569 |
20.30 |
| 2026-04-03 12:00 |
20:02:58.13 |
-10:24:12.0 |
HIP 98569 |
24.91 |
| 2026-04-04 00:00 |
20:03:19.20 |
-10:22:16.9 |
HIP 98899 |
27.88 |
| 2026-04-04 12:00 |
20:03:40.13 |
-10:20:21.8 |
HIP 98899 |
24.49 |
| 2026-04-05 00:00 |
20:04:00.90 |
-10:18:26.7 |
HIP 98899 |
21.99 |
| 2026-04-05 12:00 |
20:04:21.53 |
-10:16:31.5 |
HIP 98899 |
20.68 |
| 2026-04-06 00:00 |
20:04:42.01 |
-10:14:36.3 |
HIP 98899 |
20.76 |
| 2026-04-06 12:00 |
20:05:02.33 |
-10:12:41.1 |
HIP 98899 |
22.18 |
| 2026-04-07 00:00 |
20:05:22.51 |
-10:10:45.9 |
HIP 98899 |
24.70 |
| 2026-04-07 12:00 |
20:05:42.53 |
-10:08:50.8 |
HIP 98899 |
28.00 |
| 2026-04-08 00:00 |
20:06:02.39 |
-10:06:55.6 |
HIP 98899 |
31.83 |
| 2026-04-08 12:00 |
20:06:22.11 |
-10:05:00.5 |
HIP 99221 |
31.82 |
| 2026-04-09 00:00 |
20:06:41.66 |
-10:03:05.4 |
HIP 99221 |
26.99 |
| 2026-04-09 12:00 |
20:07:01.06 |
-10:01:10.4 |
HIP 99221 |
22.36 |
| 2026-04-10 00:00 |
20:07:20.29 |
-09:59:15.4 |
HIP 99221 |
18.04 |
| 2026-04-10 12:00 |
20:07:39.37 |
-09:57:20.5 |
HIP 99221 |
14.29 |
| 2026-04-11 00:00 |
20:07:58.29 |
-09:55:25.6 |
HIP 99221 |
11.63 |
| 2026-04-11 12:00 |
20:08:17.04 |
-09:53:30.8 |
HIP 99221 |
10.82 |
| 2026-04-12 00:00 |
20:08:35.63 |
-09:51:36.1 |
HIP 99221 |
12.20 |
| 2026-04-12 12:00 |
20:08:54.06 |
-09:49:41.5 |
HIP 99221 |
15.14 |
| 2026-04-13 00:00 |
20:09:12.32 |
-09:47:47.0 |
HIP 99221 |
18.90 |
| 2026-04-13 12:00 |
20:09:30.41 |
-09:45:52.6 |
HIP 99221 |
23.06 |
| 2026-04-14 00:00 |
20:09:48.33 |
-09:43:58.4 |
HIP 99221 |
27.41 |
| 2026-04-14 12:00 |
20:10:06.08 |
-09:42:04.3 |
HIP 99221 |
31.86 |
| 2026-04-15 00:00 |
20:10:23.66 |
-09:40:10.3 |
HIP 99582 |
32.17 |
| 2026-04-15 12:00 |
20:10:41.07 |
-09:38:16.5 |
HIP 99582 |
28.09 |
| 2026-04-16 00:00 |
20:10:58.31 |
-09:36:22.8 |
HIP 99582 |
24.28 |