| 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) |
| 2026-06-01 00:00 |
16:28:25.54 |
-70:02:17.3 |
HIP 80686 |
2.80 |
| 2026-06-01 12:00 |
16:28:11.02 |
-70:02:15.1 |
HIP 80686 |
3.17 |
| 2026-06-02 00:00 |
16:27:56.50 |
-70:02:12.4 |
HIP 80686 |
3.92 |
| 2026-06-02 12:00 |
16:27:41.99 |
-70:02:09.2 |
HIP 80686 |
4.88 |
| 2026-06-03 00:00 |
16:27:27.50 |
-70:02:05.4 |
HIP 80686 |
5.95 |
| 2026-06-03 12:00 |
16:27:13.01 |
-70:02:01.1 |
HIP 80686 |
7.07 |
| 2026-06-04 00:00 |
16:26:58.53 |
-70:01:56.2 |
HIP 80686 |
8.24 |
| 2026-06-04 12:00 |
16:26:44.07 |
-70:01:50.8 |
HIP 80686 |
9.42 |
| 2026-06-05 00:00 |
16:26:29.62 |
-70:01:44.8 |
HIP 80686 |
10.61 |
| 2026-06-05 12:00 |
16:26:15.19 |
-70:01:38.3 |
HIP 80686 |
11.82 |
| 2026-06-06 00:00 |
16:26:00.78 |
-70:01:31.3 |
HIP 80342 |
12.24 |
| 2026-06-06 12:00 |
16:25:46.39 |
-70:01:23.7 |
HIP 80342 |
11.35 |
| 2026-06-07 00:00 |
16:25:32.01 |
-70:01:15.6 |
HIP 80342 |
10.54 |
| 2026-06-07 12:00 |
16:25:17.66 |
-70:01:07.0 |
HIP 80342 |
9.82 |
| 2026-06-08 00:00 |
16:25:03.33 |
-70:00:57.8 |
HIP 80342 |
9.23 |
| 2026-06-08 12:00 |
16:24:49.02 |
-70:00:48.2 |
HIP 80342 |
8.77 |
| 2026-06-09 00:00 |
16:24:34.75 |
-70:00:37.9 |
HIP 80342 |
8.48 |
| 2026-06-09 12:00 |
16:24:20.49 |
-70:00:27.2 |
HIP 80342 |
8.37 |
| 2026-06-10 00:00 |
16:24:06.27 |
-70:00:15.9 |
HIP 80342 |
8.44 |
| 2026-06-10 12:00 |
16:23:52.08 |
-70:00:04.1 |
HIP 80342 |
8.70 |
| 2026-06-11 00:00 |
16:23:37.91 |
-69:59:51.8 |
HIP 80342 |
9.13 |
| 2026-06-11 12:00 |
16:23:23.78 |
-69:59:39.0 |
HIP 80342 |
9.70 |
| 2026-06-12 00:00 |
16:23:09.69 |
-69:59:25.6 |
HIP 80342 |
10.39 |
| 2026-06-12 12:00 |
16:22:55.63 |
-69:59:11.8 |
HIP 80342 |
11.18 |
| 2026-06-13 00:00 |
16:22:41.60 |
-69:58:57.4 |
HIP 80342 |
12.04 |
| 2026-06-13 12:00 |
16:22:27.62 |
-69:58:42.5 |
HIP 80022 |
12.29 |
| 2026-06-14 00:00 |
16:22:13.67 |
-69:58:27.1 |
HIP 80022 |
11.08 |
| 2026-06-14 12:00 |
16:21:59.77 |
-69:58:11.2 |
HIP 80022 |
9.88 |
| 2026-06-15 00:00 |
16:21:45.91 |
-69:57:54.8 |
HIP 80022 |
8.68 |
| 2026-06-15 12:00 |
16:21:32.09 |
-69:57:37.9 |
HIP 80022 |
7.50 |
| 2026-06-16 00:00 |
16:21:18.32 |
-69:57:20.5 |
HIP 80022 |
6.34 |
| 2026-06-16 12:00 |
16:21:04.59 |
-69:57:02.6 |
HIP 80022 |
5.20 |
| 2026-06-17 00:00 |
16:20:50.91 |
-69:56:44.2 |
HIP 80022 |
4.12 |
| 2026-06-17 12:00 |
16:20:37.28 |
-69:56:25.3 |
HIP 80022 |
3.13 |
| 2026-06-18 00:00 |
16:20:23.70 |
-69:56:05.9 |
HIP 80022 |
2.37 |
| 2026-06-18 12:00 |
16:20:10.18 |
-69:55:46.0 |
HIP 80022 |
2.09 |
| 2026-06-19 00:00 |
16:19:56.71 |
-69:55:25.7 |
HIP 80022 |
2.47 |
| 2026-06-19 12:00 |
16:19:43.29 |
-69:55:04.9 |
HIP 80022 |
3.27 |
| 2026-06-20 00:00 |
16:19:29.92 |
-69:54:43.6 |
HIP 80022 |
4.27 |
| 2026-06-20 12:00 |
16:19:16.62 |
-69:54:21.8 |
HIP 80022 |
5.36 |
| 2026-06-21 00:00 |
16:19:03.37 |
-69:53:59.6 |
HIP 80022 |
6.48 |
| 2026-06-21 12:00 |
16:18:50.18 |
-69:53:36.9 |
HIP 80022 |
7.63 |
| 2026-06-22 00:00 |
16:18:37.05 |
-69:53:13.8 |
HIP 80022 |
8.79 |