| 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) |
| 2026-03-26 00:00 |
16:53:08.11 |
-68:51:57.2 |
HIP 82649 |
11.71 |
| 2026-03-26 12:00 |
16:53:03.36 |
-68:52:53.8 |
HIP 82649 |
10.93 |
| 2026-03-27 00:00 |
16:52:58.49 |
-68:53:50.2 |
HIP 82649 |
10.19 |
| 2026-03-27 12:00 |
16:52:53.50 |
-68:54:46.4 |
HIP 82649 |
9.53 |
| 2026-03-28 00:00 |
16:52:48.39 |
-68:55:42.3 |
HIP 82649 |
8.94 |
| 2026-03-28 12:00 |
16:52:43.16 |
-68:56:38.0 |
HIP 82649 |
8.45 |
| 2026-03-29 00:00 |
16:52:37.82 |
-68:57:33.5 |
HIP 82649 |
8.07 |
| 2026-03-29 12:00 |
16:52:32.35 |
-68:58:28.8 |
HIP 82649 |
7.82 |
| 2026-03-30 00:00 |
16:52:26.76 |
-68:59:23.8 |
HIP 82649 |
7.72 |
| 2026-03-30 12:00 |
16:52:21.06 |
-69:00:18.6 |
HIP 82649 |
7.77 |
| 2026-03-31 00:00 |
16:52:15.24 |
-69:01:13.1 |
HIP 82649 |
7.97 |
| 2026-03-31 12:00 |
16:52:09.30 |
-69:02:07.4 |
HIP 82649 |
8.31 |
| 2026-04-01 00:00 |
16:52:03.24 |
-69:03:01.5 |
HIP 82649 |
8.77 |
| 2026-04-01 12:00 |
16:51:57.06 |
-69:03:55.3 |
HIP 82649 |
9.34 |
| 2026-04-02 00:00 |
16:51:50.77 |
-69:04:48.8 |
HIP 82649 |
10.00 |
| 2026-04-02 12:00 |
16:51:44.36 |
-69:05:42.1 |
HIP 82649 |
10.73 |
| 2026-04-03 00:00 |
16:51:37.83 |
-69:06:35.1 |
HIP 82649 |
11.51 |
| 2026-04-03 12:00 |
16:51:31.19 |
-69:07:27.8 |
HIP 82649 |
12.35 |
| 2026-04-04 00:00 |
16:51:24.43 |
-69:08:20.2 |
HIP 82649 |
13.22 |
| 2026-04-04 12:00 |
16:51:17.56 |
-69:09:12.4 |
HIP 82649 |
14.13 |
| 2026-04-05 00:00 |
16:51:10.57 |
-69:10:04.3 |
HIP 82649 |
15.06 |
| 2026-04-05 12:00 |
16:51:03.46 |
-69:10:55.9 |
HIP 82273 |
15.81 |
| 2026-04-06 00:00 |
16:50:56.24 |
-69:11:47.2 |
HIP 82273 |
15.82 |
| 2026-04-06 12:00 |
16:50:48.91 |
-69:12:38.2 |
HIP 82273 |
15.90 |
| 2026-04-07 00:00 |
16:50:41.46 |
-69:13:28.9 |
HIP 82273 |
16.03 |
| 2026-04-07 12:00 |
16:50:33.90 |
-69:14:19.3 |
HIP 82273 |
16.23 |
| 2026-04-08 00:00 |
16:50:26.22 |
-69:15:09.3 |
HIP 82273 |
16.49 |
| 2026-04-08 12:00 |
16:50:18.43 |
-69:15:59.1 |
HIP 82273 |
16.80 |
| 2026-04-09 00:00 |
16:50:10.53 |
-69:16:48.6 |
HIP 82322 |
15.94 |
| 2026-04-09 12:00 |
16:50:02.52 |
-69:17:37.7 |
HIP 82322 |
14.95 |
| 2026-04-10 00:00 |
16:49:54.39 |
-69:18:26.5 |
HIP 82322 |
13.98 |
| 2026-04-10 12:00 |
16:49:46.16 |
-69:19:14.9 |
HIP 82322 |
13.02 |
| 2026-04-11 00:00 |
16:49:37.81 |
-69:20:03.1 |
HIP 82322 |
12.10 |
| 2026-04-11 12:00 |
16:49:29.35 |
-69:20:50.9 |
HIP 82322 |
11.20 |
| 2026-04-12 00:00 |
16:49:20.79 |
-69:21:38.3 |
HIP 82322 |
10.35 |
| 2026-04-12 12:00 |
16:49:12.11 |
-69:22:25.4 |
HIP 82322 |
9.56 |
| 2026-04-13 00:00 |
16:49:03.32 |
-69:23:12.1 |
HIP 82322 |
8.83 |
| 2026-04-13 12:00 |
16:48:54.43 |
-69:23:58.5 |
HIP 82322 |
8.20 |
| 2026-04-14 00:00 |
16:48:45.43 |
-69:24:44.6 |
HIP 82322 |
7.68 |
| 2026-04-14 12:00 |
16:48:36.32 |
-69:25:30.2 |
HIP 82322 |
7.30 |
| 2026-04-15 00:00 |
16:48:27.11 |
-69:26:15.5 |
HIP 82322 |
7.08 |
| 2026-04-15 12:00 |
16:48:17.79 |
-69:27:00.4 |
HIP 82322 |
7.05 |
| 2026-04-16 00:00 |
16:48:08.37 |
-69:27:44.9 |
HIP 82322 |
7.19 |