| 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) |
| 2026-03-26 00:00 |
12:45:41.39 |
-59:32:07.9 |
HIP 62434 |
17.95 |
| 2026-03-26 12:00 |
12:45:32.46 |
-59:32:05.3 |
HIP 62434 |
18.95 |
| 2026-03-27 00:00 |
12:45:23.52 |
-59:32:02.1 |
HIP 62434 |
19.97 |
| 2026-03-27 12:00 |
12:45:14.57 |
-59:31:58.4 |
HIP 62434 |
21.01 |
| 2026-03-28 00:00 |
12:45:05.62 |
-59:31:54.0 |
HIP 62434 |
22.06 |
| 2026-03-28 12:00 |
12:44:56.65 |
-59:31:49.1 |
HIP 62434 |
23.12 |
| 2026-03-29 00:00 |
12:44:47.68 |
-59:31:43.6 |
HIP 61966 |
23.60 |
| 2026-03-29 12:00 |
12:44:38.71 |
-59:31:37.5 |
HIP 61966 |
22.61 |
| 2026-03-30 00:00 |
12:44:29.73 |
-59:31:30.9 |
HIP 61966 |
21.63 |
| 2026-03-30 12:00 |
12:44:20.75 |
-59:31:23.7 |
HIP 61966 |
20.68 |
| 2026-03-31 00:00 |
12:44:11.76 |
-59:31:15.9 |
HIP 61966 |
19.75 |
| 2026-03-31 12:00 |
12:44:02.78 |
-59:31:07.6 |
HIP 61966 |
18.85 |
| 2026-04-01 00:00 |
12:43:53.79 |
-59:30:58.7 |
HIP 61966 |
17.98 |
| 2026-04-01 12:00 |
12:43:44.80 |
-59:30:49.2 |
HIP 61966 |
17.15 |
| 2026-04-02 00:00 |
12:43:35.81 |
-59:30:39.2 |
HIP 61966 |
16.36 |
| 2026-04-02 12:00 |
12:43:26.83 |
-59:30:28.6 |
HIP 61966 |
15.63 |
| 2026-04-03 00:00 |
12:43:17.84 |
-59:30:17.4 |
HIP 61966 |
14.95 |
| 2026-04-03 12:00 |
12:43:08.86 |
-59:30:05.7 |
HIP 61966 |
14.35 |
| 2026-04-04 00:00 |
12:42:59.88 |
-59:29:53.4 |
HIP 61966 |
13.82 |
| 2026-04-04 12:00 |
12:42:50.91 |
-59:29:40.5 |
HIP 61966 |
13.37 |
| 2026-04-05 00:00 |
12:42:41.94 |
-59:29:27.2 |
HIP 61966 |
13.03 |
| 2026-04-05 12:00 |
12:42:32.97 |
-59:29:13.2 |
HIP 61966 |
12.79 |
| 2026-04-06 00:00 |
12:42:24.02 |
-59:28:58.7 |
HIP 61966 |
12.66 |
| 2026-04-06 12:00 |
12:42:15.07 |
-59:28:43.6 |
HIP 61966 |
12.64 |
| 2026-04-07 00:00 |
12:42:06.13 |
-59:28:28.0 |
HIP 61966 |
12.74 |
| 2026-04-07 12:00 |
12:41:57.20 |
-59:28:11.9 |
HIP 61966 |
12.95 |
| 2026-04-08 00:00 |
12:41:48.28 |
-59:27:55.2 |
HIP 61966 |
13.27 |
| 2026-04-08 12:00 |
12:41:39.37 |
-59:27:38.0 |
HIP 61966 |
13.69 |
| 2026-04-09 00:00 |
12:41:30.47 |
-59:27:20.2 |
HIP 61808 |
13.74 |
| 2026-04-09 12:00 |
12:41:21.58 |
-59:27:01.8 |
HIP 61808 |
13.02 |
| 2026-04-10 00:00 |
12:41:12.71 |
-59:26:43.0 |
HIP 61808 |
12.38 |
| 2026-04-10 12:00 |
12:41:03.85 |
-59:26:23.6 |
HIP 61808 |
11.82 |
| 2026-04-11 00:00 |
12:40:55.01 |
-59:26:03.7 |
HIP 61808 |
11.37 |
| 2026-04-11 12:00 |
12:40:46.18 |
-59:25:43.2 |
HIP 61808 |
11.03 |
| 2026-04-12 00:00 |
12:40:37.37 |
-59:25:22.2 |
HIP 61808 |
10.82 |
| 2026-04-12 12:00 |
12:40:28.58 |
-59:25:00.7 |
HIP 61808 |
10.74 |
| 2026-04-13 00:00 |
12:40:19.80 |
-59:24:38.6 |
HIP 61808 |
10.79 |
| 2026-04-13 12:00 |
12:40:11.04 |
-59:24:16.0 |
HIP 61808 |
10.98 |
| 2026-04-14 00:00 |
12:40:02.31 |
-59:23:53.0 |
HIP 61808 |
11.30 |
| 2026-04-14 12:00 |
12:39:53.59 |
-59:23:29.3 |
HIP 61808 |
11.74 |
| 2026-04-15 00:00 |
12:39:44.90 |
-59:23:05.2 |
HIP 61808 |
12.28 |
| 2026-04-15 12:00 |
12:39:36.22 |
-59:22:40.6 |
HIP 61808 |
12.91 |
| 2026-04-16 00:00 |
12:39:27.57 |
-59:22:15.4 |
HIP 61808 |
13.63 |