| Parameter |
Value |
| Designation |
C/2016 M1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-08-10T04:14:19.821120Z |
| Orbit solution date (soln_date, UTC) |
2022-03-09T09:02:19Z |
| Obs used |
3553 |
| NEO |
- |
| M1 |
8.400 |
| K1 |
6.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-01-25.0000000 |
| e |
0.99907148 |
| q (au) |
2.210500 |
| a (au) |
2380.662751 |
| i (deg) |
90.993781 |
| Ω (om, deg) |
92.204019 |
| ω (w, deg) |
209.825799 |
| M (ma, deg) |
359.998327 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.650 + 3.587\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.650 |
| n |
3.587 |
| gf |
1.000 |
| gb |
-0.868 |
| k |
0.997 |
| 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 |
| 2016-04-11 |
2017-08-24 |
-0.4988 |
+0.462 |
| 2017-08-24 |
2018-08-10 |
+3.5426 |
-2.264 |
| 2018-08-10 |
2022-03-01 |
+3.6685 |
-3.220 |
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 |
06:21:15.82 |
+15:09:26.6 |
HIP 30180 |
27.39 |
| 2026-09-20 12:00 |
06:21:16.46 |
+15:09:22.9 |
HIP 30180 |
27.35 |
| 2026-09-21 00:00 |
06:21:17.05 |
+15:09:19.2 |
HIP 30180 |
27.31 |
| 2026-09-21 12:00 |
06:21:17.60 |
+15:09:15.5 |
HIP 30180 |
27.27 |
| 2026-09-22 00:00 |
06:21:18.09 |
+15:09:11.9 |
HIP 30180 |
27.23 |
| 2026-09-22 12:00 |
06:21:18.53 |
+15:09:08.2 |
HIP 30180 |
27.19 |
| 2026-09-23 00:00 |
06:21:18.93 |
+15:09:04.6 |
HIP 30180 |
27.14 |
| 2026-09-23 12:00 |
06:21:19.27 |
+15:09:01.0 |
HIP 30180 |
27.10 |
| 2026-09-24 00:00 |
06:21:19.56 |
+15:08:57.4 |
HIP 30180 |
27.05 |
| 2026-09-24 12:00 |
06:21:19.81 |
+15:08:53.8 |
HIP 30180 |
27.00 |
| 2026-09-25 00:00 |
06:21:20.00 |
+15:08:50.2 |
HIP 30180 |
26.95 |
| 2026-09-25 12:00 |
06:21:20.15 |
+15:08:46.7 |
HIP 30180 |
26.90 |
| 2026-09-26 00:00 |
06:21:20.24 |
+15:08:43.2 |
HIP 30180 |
26.84 |
| 2026-09-26 12:00 |
06:21:20.29 |
+15:08:39.7 |
HIP 30180 |
26.79 |
| 2026-09-27 00:00 |
06:21:20.28 |
+15:08:36.2 |
HIP 30180 |
26.73 |
| 2026-09-27 12:00 |
06:21:20.22 |
+15:08:32.7 |
HIP 30180 |
26.67 |
| 2026-09-28 00:00 |
06:21:20.12 |
+15:08:29.3 |
HIP 30180 |
26.61 |
| 2026-09-28 12:00 |
06:21:19.96 |
+15:08:25.9 |
HIP 30180 |
26.55 |
| 2026-09-29 00:00 |
06:21:19.75 |
+15:08:22.5 |
HIP 30180 |
26.48 |
| 2026-09-29 12:00 |
06:21:19.50 |
+15:08:19.1 |
HIP 30180 |
26.42 |
| 2026-09-30 00:00 |
06:21:19.19 |
+15:08:15.7 |
HIP 30180 |
26.35 |
| 2026-09-30 12:00 |
06:21:18.83 |
+15:08:12.4 |
HIP 30180 |
26.28 |
| 2026-10-01 00:00 |
06:21:18.42 |
+15:08:09.1 |
HIP 30180 |
26.21 |
| 2026-10-01 12:00 |
06:21:17.96 |
+15:08:05.9 |
HIP 30180 |
26.14 |
| 2026-10-02 00:00 |
06:21:17.45 |
+15:08:02.7 |
HIP 30180 |
26.07 |
| 2026-10-02 12:00 |
06:21:16.88 |
+15:07:59.5 |
HIP 30180 |
25.99 |
| 2026-10-03 00:00 |
06:21:16.27 |
+15:07:56.3 |
HIP 30180 |
25.92 |
| 2026-10-03 12:00 |
06:21:15.61 |
+15:07:53.2 |
HIP 30180 |
25.84 |
| 2026-10-04 00:00 |
06:21:14.89 |
+15:07:50.0 |
HIP 30180 |
25.77 |
| 2026-10-04 12:00 |
06:21:14.12 |
+15:07:47.0 |
HIP 30180 |
25.69 |
| 2026-10-05 00:00 |
06:21:13.31 |
+15:07:43.9 |
HIP 30180 |
25.62 |
| 2026-10-05 12:00 |
06:21:12.44 |
+15:07:41.0 |
HIP 30180 |
25.55 |
| 2026-10-06 00:00 |
06:21:11.52 |
+15:07:38.0 |
HIP 30180 |
25.47 |
| 2026-10-06 12:00 |
06:21:10.55 |
+15:07:35.1 |
HIP 30180 |
25.40 |
| 2026-10-07 00:00 |
06:21:09.52 |
+15:07:32.2 |
HIP 30180 |
25.33 |
| 2026-10-07 12:00 |
06:21:08.45 |
+15:07:29.3 |
HIP 30180 |
25.27 |
| 2026-10-08 00:00 |
06:21:07.32 |
+15:07:26.5 |
HIP 30180 |
25.20 |
| 2026-10-08 12:00 |
06:21:06.15 |
+15:07:23.8 |
HIP 30180 |
25.14 |
| 2026-10-09 00:00 |
06:21:04.92 |
+15:07:21.1 |
HIP 30180 |
25.08 |
| 2026-10-09 12:00 |
06:21:03.64 |
+15:07:18.4 |
HIP 30180 |
25.02 |
| 2026-10-10 00:00 |
06:21:02.31 |
+15:07:15.8 |
HIP 30180 |
24.97 |
| 2026-10-10 12:00 |
06:21:00.92 |
+15:07:13.2 |
HIP 30180 |
24.93 |
| 2026-10-11 00:00 |
06:20:59.49 |
+15:07:10.7 |
HIP 30180 |
24.89 |