| 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 |
1.000 |
| gb |
-0.940 |
| k |
1.000 |
| 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 |
| 2016-03-01 |
2020-05-24 |
+17.7347 |
-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) |
| 2026-03-26 00:00 |
16:42:35.10 |
+30:58:38.2 |
HIP 81726 |
14.30 |
| 2026-03-26 12:00 |
16:42:33.80 |
+30:59:47.6 |
HIP 81811 |
13.18 |
| 2026-03-27 00:00 |
16:42:32.45 |
+31:00:56.9 |
HIP 81811 |
12.03 |
| 2026-03-27 12:00 |
16:42:31.05 |
+31:02:05.9 |
HIP 81811 |
10.90 |
| 2026-03-28 00:00 |
16:42:29.60 |
+31:03:14.8 |
HIP 81811 |
9.79 |
| 2026-03-28 12:00 |
16:42:28.09 |
+31:04:23.5 |
HIP 81811 |
8.71 |
| 2026-03-29 00:00 |
16:42:26.53 |
+31:05:32.1 |
HIP 81811 |
7.66 |
| 2026-03-29 12:00 |
16:42:24.92 |
+31:06:40.4 |
HIP 81811 |
6.67 |
| 2026-03-30 00:00 |
16:42:23.26 |
+31:07:48.5 |
HIP 81811 |
5.76 |
| 2026-03-30 12:00 |
16:42:21.54 |
+31:08:56.4 |
HIP 81811 |
4.97 |
| 2026-03-31 00:00 |
16:42:19.77 |
+31:10:04.1 |
HIP 81811 |
4.39 |
| 2026-03-31 12:00 |
16:42:17.96 |
+31:11:11.6 |
HIP 81811 |
4.09 |
| 2026-04-01 00:00 |
16:42:16.09 |
+31:12:18.9 |
HIP 81811 |
4.14 |
| 2026-04-01 12:00 |
16:42:14.17 |
+31:13:26.0 |
HIP 81811 |
4.52 |
| 2026-04-02 00:00 |
16:42:12.20 |
+31:14:32.8 |
HIP 81811 |
5.16 |
| 2026-04-02 12:00 |
16:42:10.18 |
+31:15:39.4 |
HIP 81811 |
5.99 |
| 2026-04-03 00:00 |
16:42:08.11 |
+31:16:45.7 |
HIP 81811 |
6.92 |
| 2026-04-03 12:00 |
16:42:05.99 |
+31:17:51.9 |
HIP 81811 |
7.93 |
| 2026-04-04 00:00 |
16:42:03.82 |
+31:18:57.7 |
HIP 81811 |
8.99 |
| 2026-04-04 12:00 |
16:42:01.60 |
+31:20:03.3 |
HIP 81811 |
10.09 |
| 2026-04-05 00:00 |
16:41:59.33 |
+31:21:08.7 |
HIP 81811 |
11.21 |
| 2026-04-05 12:00 |
16:41:57.01 |
+31:22:13.8 |
HIP 81811 |
12.34 |
| 2026-04-06 00:00 |
16:41:54.64 |
+31:23:18.6 |
HIP 81811 |
13.49 |
| 2026-04-06 12:00 |
16:41:52.22 |
+31:24:23.2 |
HIP 81693 |
13.87 |
| 2026-04-07 00:00 |
16:41:49.76 |
+31:25:27.4 |
HIP 81693 |
12.68 |
| 2026-04-07 12:00 |
16:41:47.25 |
+31:26:31.4 |
HIP 81693 |
11.50 |
| 2026-04-08 00:00 |
16:41:44.69 |
+31:27:35.1 |
HIP 81693 |
10.31 |
| 2026-04-08 12:00 |
16:41:42.08 |
+31:28:38.6 |
HIP 81693 |
9.13 |
| 2026-04-09 00:00 |
16:41:39.42 |
+31:29:41.7 |
HIP 81693 |
7.94 |
| 2026-04-09 12:00 |
16:41:36.72 |
+31:30:44.5 |
HIP 81693 |
6.76 |
| 2026-04-10 00:00 |
16:41:33.97 |
+31:31:47.0 |
HIP 81693 |
5.58 |
| 2026-04-10 12:00 |
16:41:31.18 |
+31:32:49.2 |
HIP 81693 |
4.40 |
| 2026-04-11 00:00 |
16:41:28.33 |
+31:33:51.1 |
HIP 81693 |
3.23 |
| 2026-04-11 12:00 |
16:41:25.44 |
+31:34:52.7 |
HIP 81693 |
2.10 |
| 2026-04-12 00:00 |
16:41:22.51 |
+31:35:53.9 |
HIP 81693 |
1.09 |
| 2026-04-12 12:00 |
16:41:19.53 |
+31:36:54.8 |
HIP 81693 |
0.91 |
| 2026-04-13 00:00 |
16:41:16.50 |
+31:37:55.4 |
HIP 81693 |
1.82 |
| 2026-04-13 12:00 |
16:41:13.43 |
+31:38:55.6 |
HIP 81693 |
2.94 |
| 2026-04-14 00:00 |
16:41:10.32 |
+31:39:55.5 |
HIP 81693 |
4.10 |
| 2026-04-14 12:00 |
16:41:07.16 |
+31:40:55.0 |
HIP 81693 |
5.28 |
| 2026-04-15 00:00 |
16:41:03.96 |
+31:41:54.2 |
HIP 81693 |
6.47 |
| 2026-04-15 12:00 |
16:41:00.71 |
+31:42:53.0 |
HIP 81693 |
7.65 |
| 2026-04-16 00:00 |
16:40:57.42 |
+31:43:51.5 |
HIP 81693 |
8.84 |