| Parameter |
Value |
| Designation |
C/2014 W2 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-03-10T11:35:51.728640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:03Z |
| Obs used |
3410 |
| NEO |
- |
| M1 |
8.100 |
| K1 |
8.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2016-02-17.0000000 |
| e |
0.99831735 |
| q (au) |
2.670189 |
| a (au) |
1586.896022 |
| i (deg) |
81.998562 |
| Ω (om, deg) |
69.962778 |
| ω (w, deg) |
85.009454 |
| M (ma, deg) |
359.999649 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.719 + 2.968\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.719 |
| n |
2.968 |
| gf |
1.000 |
| gb |
-0.730 |
| k |
0.994 |
| 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 |
| 2014-10-24 |
2015-09-28 |
+2.5743 |
-1.749 |
| 2015-09-28 |
2016-03-10 |
+6.8475 |
-3.627 |
| 2016-03-10 |
2016-10-09 |
+7.6354 |
-3.819 |
| 2016-10-09 |
2017-09-11 |
-0.5717 |
+0.375 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
16:05:34.11 |
-67:48:16.8 |
HIP 78896 |
13.80 |
| 2026-09-20 12:00 |
16:05:39.23 |
-67:47:40.0 |
HIP 78896 |
13.06 |
| 2026-09-21 00:00 |
16:05:44.45 |
-67:47:03.4 |
HIP 78896 |
12.34 |
| 2026-09-21 12:00 |
16:05:49.75 |
-67:46:27.1 |
HIP 78896 |
11.62 |
| 2026-09-22 00:00 |
16:05:55.14 |
-67:45:51.1 |
HIP 78896 |
10.91 |
| 2026-09-22 12:00 |
16:06:00.62 |
-67:45:15.3 |
HIP 78896 |
10.22 |
| 2026-09-23 00:00 |
16:06:06.18 |
-67:44:39.8 |
HIP 78896 |
9.55 |
| 2026-09-23 12:00 |
16:06:11.83 |
-67:44:04.6 |
HIP 78896 |
8.90 |
| 2026-09-24 00:00 |
16:06:17.57 |
-67:43:29.7 |
HIP 78896 |
8.28 |
| 2026-09-24 12:00 |
16:06:23.39 |
-67:42:55.1 |
HIP 78896 |
7.70 |
| 2026-09-25 00:00 |
16:06:29.30 |
-67:42:20.7 |
HIP 78896 |
7.16 |
| 2026-09-25 12:00 |
16:06:35.29 |
-67:41:46.7 |
HIP 78896 |
6.69 |
| 2026-09-26 00:00 |
16:06:41.37 |
-67:41:12.9 |
HIP 78896 |
6.29 |
| 2026-09-26 12:00 |
16:06:47.53 |
-67:40:39.4 |
HIP 78896 |
5.98 |
| 2026-09-27 00:00 |
16:06:53.77 |
-67:40:06.3 |
HIP 78896 |
5.78 |
| 2026-09-27 12:00 |
16:07:00.10 |
-67:39:33.4 |
HIP 78896 |
5.70 |
| 2026-09-28 00:00 |
16:07:06.50 |
-67:39:00.8 |
HIP 78896 |
5.74 |
| 2026-09-28 12:00 |
16:07:12.99 |
-67:38:28.5 |
HIP 78896 |
5.91 |
| 2026-09-29 00:00 |
16:07:19.56 |
-67:37:56.5 |
HIP 78896 |
6.19 |
| 2026-09-29 12:00 |
16:07:26.21 |
-67:37:24.8 |
HIP 78896 |
6.57 |
| 2026-09-30 00:00 |
16:07:32.94 |
-67:36:53.4 |
HIP 78896 |
7.04 |
| 2026-09-30 12:00 |
16:07:39.75 |
-67:36:22.4 |
HIP 78896 |
7.57 |
| 2026-10-01 00:00 |
16:07:46.63 |
-67:35:51.6 |
HIP 78896 |
8.17 |
| 2026-10-01 12:00 |
16:07:53.60 |
-67:35:21.1 |
HIP 78896 |
8.81 |
| 2026-10-02 00:00 |
16:08:00.65 |
-67:34:51.0 |
HIP 78896 |
9.49 |
| 2026-10-02 12:00 |
16:08:07.77 |
-67:34:21.2 |
HIP 78896 |
10.20 |
| 2026-10-03 00:00 |
16:08:14.97 |
-67:33:51.6 |
HIP 78896 |
10.94 |
| 2026-10-03 12:00 |
16:08:22.24 |
-67:33:22.5 |
HIP 78896 |
11.69 |
| 2026-10-04 00:00 |
16:08:29.60 |
-67:32:53.6 |
HIP 78896 |
12.47 |
| 2026-10-04 12:00 |
16:08:37.02 |
-67:32:25.0 |
HIP 79076 |
13.09 |
| 2026-10-05 00:00 |
16:08:44.53 |
-67:31:56.8 |
HIP 79076 |
12.67 |
| 2026-10-05 12:00 |
16:08:52.10 |
-67:31:28.9 |
HIP 79076 |
12.30 |
| 2026-10-06 00:00 |
16:08:59.76 |
-67:31:01.3 |
HIP 79076 |
11.99 |
| 2026-10-06 12:00 |
16:09:07.48 |
-67:30:34.1 |
HIP 79076 |
11.74 |
| 2026-10-07 00:00 |
16:09:15.28 |
-67:30:07.2 |
HIP 79076 |
11.56 |
| 2026-10-07 12:00 |
16:09:23.15 |
-67:29:40.6 |
HIP 79076 |
11.45 |
| 2026-10-08 00:00 |
16:09:31.10 |
-67:29:14.4 |
HIP 79076 |
11.42 |
| 2026-10-08 12:00 |
16:09:39.11 |
-67:28:48.5 |
HIP 79076 |
11.46 |
| 2026-10-09 00:00 |
16:09:47.20 |
-67:28:22.9 |
HIP 79076 |
11.58 |
| 2026-10-09 12:00 |
16:09:55.35 |
-67:27:57.7 |
HIP 79076 |
11.77 |
| 2026-10-10 00:00 |
16:10:03.58 |
-67:27:32.8 |
HIP 79076 |
12.04 |
| 2026-10-10 12:00 |
16:10:11.87 |
-67:27:08.3 |
HIP 79076 |
12.37 |
| 2026-10-11 00:00 |
16:10:20.23 |
-67:26:44.1 |
HIP 79076 |
12.77 |