| 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) |
| 2026-07-29 00:00 |
01:30:28.77 |
+41:07:45.2 |
HIP 6794 |
34.34 |
| 2026-07-29 12:00 |
01:30:26.67 |
+41:08:46.2 |
HIP 6794 |
34.01 |
| 2026-07-30 00:00 |
01:30:24.50 |
+41:09:46.9 |
HIP 6794 |
33.69 |
| 2026-07-30 12:00 |
01:30:22.25 |
+41:10:47.3 |
HIP 7010 |
32.77 |
| 2026-07-31 00:00 |
01:30:19.94 |
+41:11:47.4 |
HIP 7010 |
31.75 |
| 2026-07-31 12:00 |
01:30:17.56 |
+41:12:47.1 |
HIP 7010 |
30.75 |
| 2026-08-01 00:00 |
01:30:15.10 |
+41:13:46.5 |
HIP 7010 |
29.76 |
| 2026-08-01 12:00 |
01:30:12.57 |
+41:14:45.5 |
HIP 7010 |
28.78 |
| 2026-08-02 00:00 |
01:30:09.97 |
+41:15:44.2 |
HIP 7010 |
27.81 |
| 2026-08-02 12:00 |
01:30:07.29 |
+41:16:42.5 |
HIP 7010 |
26.87 |
| 2026-08-03 00:00 |
01:30:04.55 |
+41:17:40.5 |
HIP 7010 |
25.94 |
| 2026-08-03 12:00 |
01:30:01.73 |
+41:18:38.1 |
HIP 7010 |
25.03 |
| 2026-08-04 00:00 |
01:29:58.85 |
+41:19:35.4 |
HIP 7010 |
24.14 |
| 2026-08-04 12:00 |
01:29:55.89 |
+41:20:32.3 |
HIP 7010 |
23.28 |
| 2026-08-05 00:00 |
01:29:52.85 |
+41:21:28.8 |
HIP 7010 |
22.45 |
| 2026-08-05 12:00 |
01:29:49.75 |
+41:22:25.0 |
HIP 7010 |
21.66 |
| 2026-08-06 00:00 |
01:29:46.58 |
+41:23:20.8 |
HIP 7010 |
20.90 |
| 2026-08-06 12:00 |
01:29:43.33 |
+41:24:16.2 |
HIP 7010 |
20.18 |
| 2026-08-07 00:00 |
01:29:40.01 |
+41:25:11.2 |
HIP 7010 |
19.51 |
| 2026-08-07 12:00 |
01:29:36.62 |
+41:26:05.9 |
HIP 7010 |
18.89 |
| 2026-08-08 00:00 |
01:29:33.16 |
+41:27:00.1 |
HIP 7010 |
18.33 |
| 2026-08-08 12:00 |
01:29:29.63 |
+41:27:53.9 |
HIP 7010 |
17.83 |
| 2026-08-09 00:00 |
01:29:26.03 |
+41:28:47.4 |
HIP 7010 |
17.40 |
| 2026-08-09 12:00 |
01:29:22.35 |
+41:29:40.4 |
HIP 7010 |
17.05 |
| 2026-08-10 00:00 |
01:29:18.61 |
+41:30:33.1 |
HIP 7010 |
16.78 |
| 2026-08-10 12:00 |
01:29:14.79 |
+41:31:25.3 |
HIP 7010 |
16.59 |
| 2026-08-11 00:00 |
01:29:10.91 |
+41:32:17.1 |
HIP 7010 |
16.49 |
| 2026-08-11 12:00 |
01:29:06.95 |
+41:33:08.5 |
HIP 7010 |
16.49 |
| 2026-08-12 00:00 |
01:29:02.92 |
+41:33:59.4 |
HIP 7010 |
16.58 |
| 2026-08-12 12:00 |
01:28:58.82 |
+41:34:49.9 |
HIP 7010 |
16.75 |
| 2026-08-13 00:00 |
01:28:54.65 |
+41:35:40.0 |
HIP 7010 |
17.02 |
| 2026-08-13 12:00 |
01:28:50.42 |
+41:36:29.7 |
HIP 7010 |
17.37 |
| 2026-08-14 00:00 |
01:28:46.11 |
+41:37:18.9 |
HIP 7010 |
17.81 |
| 2026-08-14 12:00 |
01:28:41.73 |
+41:38:07.7 |
HIP 7010 |
18.32 |
| 2026-08-15 00:00 |
01:28:37.29 |
+41:38:56.0 |
HIP 7010 |
18.90 |
| 2026-08-15 12:00 |
01:28:32.77 |
+41:39:43.9 |
HIP 7010 |
19.55 |
| 2026-08-16 00:00 |
01:28:28.19 |
+41:40:31.3 |
HIP 7010 |
20.25 |
| 2026-08-16 12:00 |
01:28:23.54 |
+41:41:18.3 |
HIP 7010 |
21.01 |
| 2026-08-17 00:00 |
01:28:18.82 |
+41:42:04.8 |
HIP 7010 |
21.82 |
| 2026-08-17 12:00 |
01:28:14.03 |
+41:42:50.8 |
HIP 7010 |
22.67 |
| 2026-08-18 00:00 |
01:28:09.17 |
+41:43:36.4 |
HIP 7010 |
23.57 |
| 2026-08-18 12:00 |
01:28:04.25 |
+41:44:21.5 |
HIP 7010 |
24.50 |
| 2026-08-19 00:00 |
01:27:59.26 |
+41:45:06.2 |
HIP 7010 |
25.46 |