| Parameter |
Value |
| Designation |
C/2014 S2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-12-09T19:08:29.909760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:00Z |
| Obs used |
2941 |
| NEO |
- |
| M1 |
6.000 |
| K1 |
13.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2016-01-10.0000000 |
| e |
0.98762625 |
| q (au) |
2.100643 |
| a (au) |
169.766118 |
| i (deg) |
64.670381 |
| Ω (om, deg) |
8.122248 |
| ω (w, deg) |
87.806610 |
| M (ma, deg) |
0.013903 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.333 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.333 |
| n |
6.000 |
| gf |
0.802 |
| gb |
-0.500 |
| k |
0.936 |
| δ90 |
1.000 |
| 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 |
| 2014-04-28 |
2015-04-25 |
-24.2188 |
+17.742 |
| 2015-04-25 |
2015-12-09 |
+33.0276 |
-11.675 |
| 2015-12-09 |
2017-04-01 |
+2.8013 |
-2.446 |
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 |
12:29:17.93 |
-58:16:07.4 |
HIP 60884 |
7.19 |
| 2026-06-01 12:00 |
12:29:14.04 |
-58:15:12.9 |
HIP 60884 |
6.19 |
| 2026-06-02 00:00 |
12:29:10.22 |
-58:14:18.3 |
HIP 60884 |
5.21 |
| 2026-06-02 12:00 |
12:29:06.46 |
-58:13:23.6 |
HIP 60884 |
4.27 |
| 2026-06-03 00:00 |
12:29:02.78 |
-58:12:28.8 |
HIP 60884 |
3.40 |
| 2026-06-03 12:00 |
12:28:59.16 |
-58:11:33.9 |
HIP 60884 |
2.65 |
| 2026-06-04 00:00 |
12:28:55.61 |
-58:10:39.0 |
HIP 60884 |
2.15 |
| 2026-06-04 12:00 |
12:28:52.13 |
-58:09:44.0 |
HIP 60884 |
2.10 |
| 2026-06-05 00:00 |
12:28:48.72 |
-58:08:48.9 |
HIP 60884 |
2.51 |
| 2026-06-05 12:00 |
12:28:45.38 |
-58:07:53.8 |
HIP 60884 |
3.21 |
| 2026-06-06 00:00 |
12:28:42.11 |
-58:06:58.6 |
HIP 60884 |
4.05 |
| 2026-06-06 12:00 |
12:28:38.91 |
-58:06:03.4 |
HIP 60884 |
4.96 |
| 2026-06-07 00:00 |
12:28:35.78 |
-58:05:08.1 |
HIP 60884 |
5.90 |
| 2026-06-07 12:00 |
12:28:32.72 |
-58:04:12.8 |
HIP 60884 |
6.86 |
| 2026-06-08 00:00 |
12:28:29.73 |
-58:03:17.4 |
HIP 60884 |
7.83 |
| 2026-06-08 12:00 |
12:28:26.82 |
-58:02:22.0 |
HIP 60884 |
8.81 |
| 2026-06-09 00:00 |
12:28:23.97 |
-58:01:26.6 |
HIP 60884 |
9.79 |
| 2026-06-09 12:00 |
12:28:21.19 |
-58:00:31.2 |
HIP 60884 |
10.77 |
| 2026-06-10 00:00 |
12:28:18.48 |
-57:59:35.8 |
HIP 60884 |
11.75 |
| 2026-06-10 12:00 |
12:28:15.84 |
-57:58:40.3 |
HIP 60884 |
12.73 |
| 2026-06-11 00:00 |
12:28:13.28 |
-57:57:44.9 |
HIP 60884 |
13.71 |
| 2026-06-11 12:00 |
12:28:10.78 |
-57:56:49.4 |
HIP 60884 |
14.69 |
| 2026-06-12 00:00 |
12:28:08.36 |
-57:55:53.9 |
HIP 60884 |
15.66 |
| 2026-06-12 12:00 |
12:28:06.01 |
-57:54:58.5 |
HIP 60884 |
16.64 |
| 2026-06-13 00:00 |
12:28:03.73 |
-57:54:03.1 |
HIP 60884 |
17.61 |
| 2026-06-13 12:00 |
12:28:01.52 |
-57:53:07.7 |
HIP 60884 |
18.58 |
| 2026-06-14 00:00 |
12:27:59.38 |
-57:52:12.3 |
HIP 60884 |
19.54 |
| 2026-06-14 12:00 |
12:27:57.31 |
-57:51:16.9 |
HIP 60884 |
20.51 |
| 2026-06-15 00:00 |
12:27:55.31 |
-57:50:21.6 |
HIP 60884 |
21.46 |
| 2026-06-15 12:00 |
12:27:53.39 |
-57:49:26.3 |
HIP 60884 |
22.42 |
| 2026-06-16 00:00 |
12:27:51.54 |
-57:48:31.1 |
HIP 60884 |
23.37 |
| 2026-06-16 12:00 |
12:27:49.75 |
-57:47:35.9 |
HIP 60884 |
24.32 |
| 2026-06-17 00:00 |
12:27:48.04 |
-57:46:40.8 |
HIP 60884 |
25.27 |
| 2026-06-17 12:00 |
12:27:46.41 |
-57:45:45.8 |
HIP 60884 |
26.21 |
| 2026-06-18 00:00 |
12:27:44.84 |
-57:44:50.8 |
HIP 60884 |
27.15 |
| 2026-06-18 12:00 |
12:27:43.34 |
-57:43:55.8 |
HIP 60884 |
28.09 |
| 2026-06-19 00:00 |
12:27:41.92 |
-57:43:01.0 |
HIP 60639 |
28.25 |
| 2026-06-19 12:00 |
12:27:40.56 |
-57:42:06.2 |
HIP 60639 |
27.40 |
| 2026-06-20 00:00 |
12:27:39.28 |
-57:41:11.5 |
HIP 60639 |
26.57 |
| 2026-06-20 12:00 |
12:27:38.07 |
-57:40:16.9 |
HIP 60639 |
25.76 |
| 2026-06-21 00:00 |
12:27:36.93 |
-57:39:22.5 |
HIP 60639 |
24.96 |
| 2026-06-21 12:00 |
12:27:35.86 |
-57:38:28.1 |
HIP 60639 |
24.17 |
| 2026-06-22 00:00 |
12:27:34.86 |
-57:37:33.8 |
HIP 60639 |
23.40 |