| Parameter |
Value |
| Designation |
C/2016 S1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-03-16T19:29:49.666560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:26Z |
| Obs used |
127 |
| NEO |
- |
| M1 |
5.700 |
| K1 |
24.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2016-11-07.0000000 |
| e |
0.70884778 |
| q (au) |
2.411908 |
| a (au) |
8.284009 |
| i (deg) |
94.689671 |
| Ω (om, deg) |
227.538223 |
| ω (w, deg) |
273.611282 |
| M (ma, deg) |
354.633893 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.482 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.482 |
| n |
6.000 |
| gf |
0.943 |
| gb |
-0.859 |
| k |
0.992 |
| δ90 |
9.996 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
16:15:17.66 |
+63:23:22.8 |
HIP 79863 |
32.60 |
| 2026-09-20 12:00 |
16:15:25.61 |
+63:21:42.8 |
HIP 79863 |
30.73 |
| 2026-09-21 00:00 |
16:15:33.69 |
+63:20:03.3 |
HIP 79863 |
28.86 |
| 2026-09-21 12:00 |
16:15:41.91 |
+63:18:24.0 |
HIP 79863 |
26.99 |
| 2026-09-22 00:00 |
16:15:50.25 |
+63:16:45.2 |
HIP 79863 |
25.11 |
| 2026-09-22 12:00 |
16:15:58.72 |
+63:15:06.7 |
HIP 79863 |
23.23 |
| 2026-09-23 00:00 |
16:16:07.33 |
+63:13:28.7 |
HIP 79863 |
21.35 |
| 2026-09-23 12:00 |
16:16:16.05 |
+63:11:51.0 |
HIP 79863 |
19.48 |
| 2026-09-24 00:00 |
16:16:24.91 |
+63:10:13.7 |
HIP 79863 |
17.60 |
| 2026-09-24 12:00 |
16:16:33.89 |
+63:08:36.9 |
HIP 79863 |
15.72 |
| 2026-09-25 00:00 |
16:16:43.00 |
+63:07:00.4 |
HIP 79863 |
13.84 |
| 2026-09-25 12:00 |
16:16:52.23 |
+63:05:24.4 |
HIP 79863 |
11.96 |
| 2026-09-26 00:00 |
16:17:01.58 |
+63:03:48.8 |
HIP 79863 |
10.10 |
| 2026-09-26 12:00 |
16:17:11.06 |
+63:02:13.6 |
HIP 79863 |
8.25 |
| 2026-09-27 00:00 |
16:17:20.66 |
+63:00:38.9 |
HIP 79863 |
6.42 |
| 2026-09-27 12:00 |
16:17:30.38 |
+62:59:04.6 |
HIP 79863 |
4.67 |
| 2026-09-28 00:00 |
16:17:40.22 |
+62:57:30.7 |
HIP 79863 |
3.09 |
| 2026-09-28 12:00 |
16:17:50.18 |
+62:55:57.4 |
HIP 79863 |
2.16 |
| 2026-09-29 00:00 |
16:18:00.26 |
+62:54:24.4 |
HIP 79863 |
2.67 |
| 2026-09-29 12:00 |
16:18:10.46 |
+62:52:52.0 |
HIP 79863 |
4.12 |
| 2026-09-30 00:00 |
16:18:20.78 |
+62:51:20.0 |
HIP 79863 |
5.85 |
| 2026-09-30 12:00 |
16:18:31.22 |
+62:49:48.5 |
HIP 79863 |
7.67 |
| 2026-10-01 00:00 |
16:18:41.77 |
+62:48:17.4 |
HIP 79863 |
9.54 |
| 2026-10-01 12:00 |
16:18:52.43 |
+62:46:46.9 |
HIP 79863 |
11.43 |
| 2026-10-02 00:00 |
16:19:03.22 |
+62:45:16.9 |
HIP 79863 |
13.33 |
| 2026-10-02 12:00 |
16:19:14.11 |
+62:43:47.4 |
HIP 79863 |
15.24 |
| 2026-10-03 00:00 |
16:19:25.12 |
+62:42:18.3 |
HIP 79863 |
17.16 |
| 2026-10-03 12:00 |
16:19:36.25 |
+62:40:49.8 |
HIP 79861 |
18.61 |
| 2026-10-04 00:00 |
16:19:47.49 |
+62:39:21.8 |
HIP 79861 |
18.23 |
| 2026-10-04 12:00 |
16:19:58.83 |
+62:37:54.4 |
HIP 79861 |
18.06 |
| 2026-10-05 00:00 |
16:20:10.29 |
+62:36:27.5 |
HIP 79861 |
18.12 |
| 2026-10-05 12:00 |
16:20:21.86 |
+62:35:01.1 |
HIP 79861 |
18.41 |
| 2026-10-06 00:00 |
16:20:33.54 |
+62:33:35.3 |
HIP 79861 |
18.92 |
| 2026-10-06 12:00 |
16:20:45.33 |
+62:32:10.0 |
HIP 80280 |
17.55 |
| 2026-10-07 00:00 |
16:20:57.23 |
+62:30:45.3 |
HIP 80280 |
15.99 |
| 2026-10-07 12:00 |
16:21:09.23 |
+62:29:21.1 |
HIP 80280 |
14.51 |
| 2026-10-08 00:00 |
16:21:21.35 |
+62:27:57.6 |
HIP 80280 |
13.14 |
| 2026-10-08 12:00 |
16:21:33.56 |
+62:26:34.6 |
HIP 80280 |
11.92 |
| 2026-10-09 00:00 |
16:21:45.89 |
+62:25:12.2 |
HIP 80280 |
10.92 |
| 2026-10-09 12:00 |
16:21:58.31 |
+62:23:50.4 |
HIP 80280 |
10.18 |
| 2026-10-10 00:00 |
16:22:10.84 |
+62:22:29.2 |
HIP 80280 |
9.78 |
| 2026-10-10 12:00 |
16:22:23.48 |
+62:21:08.5 |
HIP 80280 |
9.76 |
| 2026-10-11 00:00 |
16:22:36.21 |
+62:19:48.6 |
HIP 80280 |
10.11 |