| Parameter |
Value |
| Designation |
C/2018 F4 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-12-04T01:26:15.930240Z |
| Orbit solution date (soln_date, UTC) |
2023-04-24T19:06:39Z |
| Obs used |
530 |
| NEO |
- |
| M1 |
5.300 |
| K1 |
13.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2018-03-17T12:40:26.976000Z |
| Discovery magnitude (MPC) |
20.40 w |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-09-20.0000000 |
| e |
1.00152144 |
| q (au) |
3.439968 |
| a (au) |
-2260.993631 |
| i (deg) |
78.098889 |
| Ω (om, deg) |
26.507082 |
| ω (w, deg) |
263.204195 |
| M (ma, deg) |
-0.000688 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.479 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.479 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.616 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2018-03-17 |
2019-12-03 |
-4.5179 |
+3.714 |
| 2019-12-04 |
2020-09-08 |
+3.2670 |
-2.149 |
| 2020-09-08 |
2021-01-03 |
+3.3546 |
-2.816 |
| 2021-01-03 |
2021-11-06 |
+2.1461 |
-1.581 |
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 |
01:11:27.58 |
+36:37:22.6 |
HIP 5595 |
13.27 |
| 2026-03-26 12:00 |
01:11:34.99 |
+36:37:59.7 |
HIP 5595 |
13.58 |
| 2026-03-27 00:00 |
01:11:42.41 |
+36:38:37.3 |
HIP 5595 |
14.08 |
| 2026-03-27 12:00 |
01:11:49.85 |
+36:39:15.2 |
HIP 5595 |
14.74 |
| 2026-03-28 00:00 |
01:11:57.29 |
+36:39:53.6 |
HIP 5595 |
15.56 |
| 2026-03-28 12:00 |
01:12:04.75 |
+36:40:32.5 |
HIP 5595 |
16.50 |
| 2026-03-29 00:00 |
01:12:12.22 |
+36:41:11.7 |
HIP 5595 |
17.55 |
| 2026-03-29 12:00 |
01:12:19.70 |
+36:41:51.4 |
HIP 5595 |
18.70 |
| 2026-03-30 00:00 |
01:12:27.19 |
+36:42:31.5 |
HIP 5595 |
19.92 |
| 2026-03-30 12:00 |
01:12:34.69 |
+36:43:12.0 |
HIP 5595 |
21.20 |
| 2026-03-31 00:00 |
01:12:42.20 |
+36:43:52.9 |
HIP 5595 |
22.54 |
| 2026-03-31 12:00 |
01:12:49.72 |
+36:44:34.2 |
HIP 5595 |
23.93 |
| 2026-04-01 00:00 |
01:12:57.25 |
+36:45:16.0 |
HIP 5595 |
25.35 |
| 2026-04-01 12:00 |
01:13:04.78 |
+36:45:58.1 |
HIP 5595 |
26.81 |
| 2026-04-02 00:00 |
01:13:12.32 |
+36:46:40.7 |
HIP 5595 |
28.30 |
| 2026-04-02 12:00 |
01:13:19.87 |
+36:47:23.7 |
HIP 5595 |
29.81 |
| 2026-04-03 00:00 |
01:13:27.43 |
+36:48:07.1 |
HIP 5595 |
31.34 |
| 2026-04-03 12:00 |
01:13:34.99 |
+36:48:50.8 |
HIP 5595 |
32.90 |
| 2026-04-04 00:00 |
01:13:42.56 |
+36:49:35.0 |
HIP 5595 |
34.47 |
| 2026-04-04 12:00 |
01:13:50.13 |
+36:50:19.6 |
HIP 5595 |
36.06 |
| 2026-04-05 00:00 |
01:13:57.71 |
+36:51:04.6 |
HIP 5595 |
37.66 |
| 2026-04-05 12:00 |
01:14:05.29 |
+36:51:49.9 |
HIP 5595 |
39.27 |
| 2026-04-06 00:00 |
01:14:12.87 |
+36:52:35.7 |
HIP 5660 |
40.67 |
| 2026-04-06 12:00 |
01:14:20.46 |
+36:53:21.9 |
HIP 5660 |
42.04 |
| 2026-04-07 00:00 |
01:14:28.05 |
+36:54:08.4 |
HIP 5660 |
43.45 |
| 2026-04-07 12:00 |
01:14:35.65 |
+36:54:55.3 |
HIP 5966 |
44.47 |
| 2026-04-08 00:00 |
01:14:43.25 |
+36:55:42.6 |
HIP 5966 |
44.28 |
| 2026-04-08 12:00 |
01:14:50.84 |
+36:56:30.3 |
HIP 5966 |
44.15 |
| 2026-04-09 00:00 |
01:14:58.44 |
+36:57:18.4 |
HIP 5749 |
44.06 |
| 2026-04-09 12:00 |
01:15:06.05 |
+36:58:06.9 |
HIP 5749 |
43.79 |
| 2026-04-10 00:00 |
01:15:13.65 |
+36:58:55.7 |
HIP 5749 |
43.58 |
| 2026-04-10 12:00 |
01:15:21.25 |
+36:59:44.9 |
HIP 5749 |
43.43 |
| 2026-04-11 00:00 |
01:15:28.85 |
+37:00:34.5 |
HIP 5749 |
43.34 |
| 2026-04-11 12:00 |
01:15:36.45 |
+37:01:24.4 |
HIP 5881 |
43.22 |
| 2026-04-12 00:00 |
01:15:44.05 |
+37:02:14.7 |
HIP 6140 |
42.02 |
| 2026-04-12 12:00 |
01:15:51.64 |
+37:03:05.4 |
HIP 6140 |
40.28 |
| 2026-04-13 00:00 |
01:15:59.24 |
+37:03:56.5 |
HIP 6140 |
38.54 |
| 2026-04-13 12:00 |
01:16:06.83 |
+37:04:47.9 |
HIP 6140 |
36.80 |
| 2026-04-14 00:00 |
01:16:14.41 |
+37:05:39.6 |
HIP 6140 |
35.06 |
| 2026-04-14 12:00 |
01:16:22.00 |
+37:06:31.7 |
HIP 6140 |
33.32 |
| 2026-04-15 00:00 |
01:16:29.58 |
+37:07:24.2 |
HIP 6140 |
31.57 |
| 2026-04-15 12:00 |
01:16:37.15 |
+37:08:17.0 |
HIP 6140 |
29.82 |
| 2026-04-16 00:00 |
01:16:44.72 |
+37:09:10.2 |
HIP 6140 |
28.07 |