| Parameter |
Value |
| Designation |
C/2016 C1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-02-19T07:06:40.415040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:23Z |
| Obs used |
236 |
| NEO |
- |
| M1 |
6.500 |
| K1 |
8.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-08-02.0000000 |
| e |
1.00512425 |
| q (au) |
8.462645 |
| a (au) |
-1651.490288 |
| i (deg) |
56.178888 |
| Ω (om, deg) |
181.780057 |
| ω (w, deg) |
328.739361 |
| M (ma, deg) |
0.007779 |
Magnitude
Scatter + Global Linear
$$
M_a = (0.005 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
0.005 |
| n |
6.000 |
| gf |
0.992 |
| gb |
-0.940 |
| k |
1.000 |
| δ90 |
9.998 |
| 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 |
| 2016-03-01 |
2020-05-24 |
+17.7344 |
-16.764 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
16:33:48.18 |
+32:39:19.4 |
HIP 81191 |
36.88 |
| 2026-06-01 12:00 |
16:33:42.84 |
+32:39:29.6 |
HIP 81191 |
37.21 |
| 2026-06-02 00:00 |
16:33:37.51 |
+32:39:39.2 |
HIP 81191 |
37.58 |
| 2026-06-02 12:00 |
16:33:32.18 |
+32:39:48.2 |
HIP 81191 |
37.99 |
| 2026-06-03 00:00 |
16:33:26.85 |
+32:39:56.7 |
HIP 81191 |
38.44 |
| 2026-06-03 12:00 |
16:33:21.52 |
+32:40:04.5 |
HIP 81191 |
38.92 |
| 2026-06-04 00:00 |
16:33:16.20 |
+32:40:11.7 |
HIP 81191 |
39.44 |
| 2026-06-04 12:00 |
16:33:10.88 |
+32:40:18.4 |
HIP 81191 |
39.98 |
| 2026-06-05 00:00 |
16:33:05.57 |
+32:40:24.4 |
HIP 81191 |
40.56 |
| 2026-06-05 12:00 |
16:33:00.26 |
+32:40:29.8 |
HIP 80866 |
40.77 |
| 2026-06-06 00:00 |
16:32:54.96 |
+32:40:34.7 |
HIP 80866 |
40.05 |
| 2026-06-06 12:00 |
16:32:49.67 |
+32:40:38.9 |
HIP 80866 |
39.35 |
| 2026-06-07 00:00 |
16:32:44.38 |
+32:40:42.5 |
HIP 80866 |
38.66 |
| 2026-06-07 12:00 |
16:32:39.10 |
+32:40:45.6 |
HIP 80866 |
37.98 |
| 2026-06-08 00:00 |
16:32:33.83 |
+32:40:48.0 |
HIP 80866 |
37.32 |
| 2026-06-08 12:00 |
16:32:28.56 |
+32:40:49.8 |
HIP 80866 |
36.67 |
| 2026-06-09 00:00 |
16:32:23.31 |
+32:40:51.1 |
HIP 80866 |
36.04 |
| 2026-06-09 12:00 |
16:32:18.06 |
+32:40:51.7 |
HIP 80866 |
35.42 |
| 2026-06-10 00:00 |
16:32:12.82 |
+32:40:51.8 |
HIP 80866 |
34.82 |
| 2026-06-10 12:00 |
16:32:07.60 |
+32:40:51.2 |
HIP 80866 |
34.24 |
| 2026-06-11 00:00 |
16:32:02.38 |
+32:40:50.1 |
HIP 80866 |
33.68 |
| 2026-06-11 12:00 |
16:31:57.18 |
+32:40:48.3 |
HIP 80866 |
33.13 |
| 2026-06-12 00:00 |
16:31:51.99 |
+32:40:46.0 |
HIP 80866 |
32.61 |
| 2026-06-12 12:00 |
16:31:46.81 |
+32:40:43.0 |
HIP 80866 |
32.10 |
| 2026-06-13 00:00 |
16:31:41.64 |
+32:40:39.5 |
HIP 80866 |
31.62 |
| 2026-06-13 12:00 |
16:31:36.49 |
+32:40:35.4 |
HIP 80866 |
31.16 |
| 2026-06-14 00:00 |
16:31:31.35 |
+32:40:30.7 |
HIP 80866 |
30.73 |
| 2026-06-14 12:00 |
16:31:26.23 |
+32:40:25.3 |
HIP 80866 |
30.32 |
| 2026-06-15 00:00 |
16:31:21.12 |
+32:40:19.4 |
HIP 80866 |
29.93 |
| 2026-06-15 12:00 |
16:31:16.03 |
+32:40:12.9 |
HIP 80866 |
29.57 |
| 2026-06-16 00:00 |
16:31:10.95 |
+32:40:05.9 |
HIP 80866 |
29.23 |
| 2026-06-16 12:00 |
16:31:05.90 |
+32:39:58.2 |
HIP 80866 |
28.93 |
| 2026-06-17 00:00 |
16:31:00.85 |
+32:39:49.9 |
HIP 80866 |
28.65 |
| 2026-06-17 12:00 |
16:30:55.83 |
+32:39:41.1 |
HIP 80866 |
28.39 |
| 2026-06-18 00:00 |
16:30:50.83 |
+32:39:31.6 |
HIP 80866 |
28.17 |
| 2026-06-18 12:00 |
16:30:45.84 |
+32:39:21.6 |
HIP 80866 |
27.98 |
| 2026-06-19 00:00 |
16:30:40.87 |
+32:39:11.1 |
HIP 80866 |
27.82 |
| 2026-06-19 12:00 |
16:30:35.93 |
+32:38:59.9 |
HIP 80866 |
27.68 |
| 2026-06-20 00:00 |
16:30:31.00 |
+32:38:48.2 |
HIP 80866 |
27.58 |
| 2026-06-20 12:00 |
16:30:26.10 |
+32:38:35.8 |
HIP 80866 |
27.51 |
| 2026-06-21 00:00 |
16:30:21.21 |
+32:38:23.0 |
HIP 80866 |
27.46 |
| 2026-06-21 12:00 |
16:30:16.35 |
+32:38:09.5 |
HIP 80866 |
27.45 |
| 2026-06-22 00:00 |
16:30:11.51 |
+32:37:55.5 |
HIP 80866 |
27.47 |