| 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) |
| 2026-07-29 00:00 |
06:16:04.63 |
+15:13:50.3 |
HIP 29779 |
16.16 |
| 2026-07-29 12:00 |
06:16:09.38 |
+15:13:50.6 |
HIP 29779 |
16.05 |
| 2026-07-30 00:00 |
06:16:14.10 |
+15:13:50.8 |
HIP 29779 |
16.02 |
| 2026-07-30 12:00 |
06:16:18.79 |
+15:13:50.9 |
HIP 29779 |
16.08 |
| 2026-07-31 00:00 |
06:16:23.46 |
+15:13:51.0 |
HIP 29779 |
16.21 |
| 2026-07-31 12:00 |
06:16:28.10 |
+15:13:51.0 |
HIP 29779 |
16.43 |
| 2026-08-01 00:00 |
06:16:32.72 |
+15:13:50.9 |
HIP 29779 |
16.71 |
| 2026-08-01 12:00 |
06:16:37.31 |
+15:13:50.7 |
HIP 29779 |
17.06 |
| 2026-08-02 00:00 |
06:16:41.88 |
+15:13:50.4 |
HIP 29779 |
17.47 |
| 2026-08-02 12:00 |
06:16:46.42 |
+15:13:50.1 |
HIP 29779 |
17.94 |
| 2026-08-03 00:00 |
06:16:50.93 |
+15:13:49.7 |
HIP 29779 |
18.46 |
| 2026-08-03 12:00 |
06:16:55.41 |
+15:13:49.2 |
HIP 29779 |
19.03 |
| 2026-08-04 00:00 |
06:16:59.87 |
+15:13:48.7 |
HIP 29779 |
19.63 |
| 2026-08-04 12:00 |
06:17:04.30 |
+15:13:48.1 |
HIP 29779 |
20.27 |
| 2026-08-05 00:00 |
06:17:08.70 |
+15:13:47.4 |
HIP 29779 |
20.95 |
| 2026-08-05 12:00 |
06:17:13.07 |
+15:13:46.6 |
HIP 29779 |
21.65 |
| 2026-08-06 00:00 |
06:17:17.41 |
+15:13:45.8 |
HIP 29988 |
21.48 |
| 2026-08-06 12:00 |
06:17:21.73 |
+15:13:44.9 |
HIP 29988 |
20.45 |
| 2026-08-07 00:00 |
06:17:26.01 |
+15:13:43.9 |
HIP 29988 |
19.43 |
| 2026-08-07 12:00 |
06:17:30.27 |
+15:13:42.9 |
HIP 29988 |
18.42 |
| 2026-08-08 00:00 |
06:17:34.49 |
+15:13:41.8 |
HIP 29988 |
17.42 |
| 2026-08-08 12:00 |
06:17:38.69 |
+15:13:40.6 |
HIP 29988 |
16.43 |
| 2026-08-09 00:00 |
06:17:42.85 |
+15:13:39.4 |
HIP 29988 |
15.45 |
| 2026-08-09 12:00 |
06:17:46.98 |
+15:13:38.1 |
HIP 29988 |
14.49 |
| 2026-08-10 00:00 |
06:17:51.08 |
+15:13:36.7 |
HIP 29988 |
13.53 |
| 2026-08-10 12:00 |
06:17:55.15 |
+15:13:35.3 |
HIP 29988 |
12.58 |
| 2026-08-11 00:00 |
06:17:59.19 |
+15:13:33.8 |
HIP 29988 |
11.65 |
| 2026-08-11 12:00 |
06:18:03.19 |
+15:13:32.2 |
HIP 29988 |
10.74 |
| 2026-08-12 00:00 |
06:18:07.17 |
+15:13:30.6 |
HIP 29988 |
9.84 |
| 2026-08-12 12:00 |
06:18:11.11 |
+15:13:28.9 |
HIP 29988 |
8.97 |
| 2026-08-13 00:00 |
06:18:15.01 |
+15:13:27.2 |
HIP 29988 |
8.11 |
| 2026-08-13 12:00 |
06:18:18.88 |
+15:13:25.4 |
HIP 29988 |
7.29 |
| 2026-08-14 00:00 |
06:18:22.72 |
+15:13:23.5 |
HIP 29988 |
6.51 |
| 2026-08-14 12:00 |
06:18:26.53 |
+15:13:21.6 |
HIP 29988 |
5.77 |
| 2026-08-15 00:00 |
06:18:30.30 |
+15:13:19.6 |
HIP 29988 |
5.10 |
| 2026-08-15 12:00 |
06:18:34.03 |
+15:13:17.6 |
HIP 29988 |
4.53 |
| 2026-08-16 00:00 |
06:18:37.73 |
+15:13:15.5 |
HIP 29988 |
4.07 |
| 2026-08-16 12:00 |
06:18:41.40 |
+15:13:13.4 |
HIP 29988 |
3.78 |
| 2026-08-17 00:00 |
06:18:45.02 |
+15:13:11.2 |
HIP 29988 |
3.69 |
| 2026-08-17 12:00 |
06:18:48.62 |
+15:13:09.0 |
HIP 29988 |
3.80 |
| 2026-08-18 00:00 |
06:18:52.17 |
+15:13:06.7 |
HIP 29988 |
4.09 |
| 2026-08-18 12:00 |
06:18:55.70 |
+15:13:04.3 |
HIP 29988 |
4.52 |
| 2026-08-19 00:00 |
06:18:59.18 |
+15:13:02.0 |
HIP 29988 |
5.06 |