| Parameter |
Value |
| Designation |
C/2015 V4 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-08-27T23:52:13.535040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:16Z |
| Obs used |
79 |
| NEO |
- |
| M1 |
12.900 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2016-03-18.0000000 |
| e |
0.70560176 |
| q (au) |
5.459628 |
| a (au) |
18.545043 |
| i (deg) |
60.751306 |
| Ω (om, deg) |
179.896328 |
| ω (w, deg) |
306.907117 |
| M (ma, deg) |
357.988428 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.198 + 4.797\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.198 |
| n |
4.797 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
17:04:20.29 |
+38:55:05.4 |
HIP 83584 |
16.66 |
| 2026-05-12 12:00 |
17:04:13.82 |
+38:55:53.4 |
HIP 83584 |
16.59 |
| 2026-05-13 00:00 |
17:04:07.32 |
+38:56:40.6 |
HIP 83584 |
16.68 |
| 2026-05-13 12:00 |
17:04:00.78 |
+38:57:27.1 |
HIP 83584 |
16.90 |
| 2026-05-14 00:00 |
17:03:54.20 |
+38:58:12.9 |
HIP 83584 |
17.27 |
| 2026-05-14 12:00 |
17:03:47.60 |
+38:58:58.0 |
HIP 83584 |
17.77 |
| 2026-05-15 00:00 |
17:03:40.95 |
+38:59:42.3 |
HIP 83584 |
18.38 |
| 2026-05-15 12:00 |
17:03:34.28 |
+39:00:25.9 |
HIP 83584 |
19.10 |
| 2026-05-16 00:00 |
17:03:27.58 |
+39:01:08.7 |
HIP 83584 |
19.92 |
| 2026-05-16 12:00 |
17:03:20.84 |
+39:01:50.8 |
HIP 83584 |
20.82 |
| 2026-05-17 00:00 |
17:03:14.07 |
+39:02:32.1 |
HIP 83584 |
21.80 |
| 2026-05-17 12:00 |
17:03:07.28 |
+39:03:12.7 |
HIP 83584 |
22.83 |
| 2026-05-18 00:00 |
17:03:00.45 |
+39:03:52.5 |
HIP 83584 |
23.93 |
| 2026-05-18 12:00 |
17:02:53.60 |
+39:04:31.6 |
HIP 83584 |
25.07 |
| 2026-05-19 00:00 |
17:02:46.72 |
+39:05:09.9 |
HIP 83584 |
26.25 |
| 2026-05-19 12:00 |
17:02:39.82 |
+39:05:47.4 |
HIP 83228 |
27.29 |
| 2026-05-20 00:00 |
17:02:32.89 |
+39:06:24.2 |
HIP 83228 |
26.34 |
| 2026-05-20 12:00 |
17:02:25.93 |
+39:07:00.2 |
HIP 83228 |
25.43 |
| 2026-05-21 00:00 |
17:02:18.95 |
+39:07:35.4 |
HIP 83228 |
24.56 |
| 2026-05-21 12:00 |
17:02:11.95 |
+39:08:09.9 |
HIP 83228 |
23.75 |
| 2026-05-22 00:00 |
17:02:04.92 |
+39:08:43.5 |
HIP 83228 |
22.99 |
| 2026-05-22 12:00 |
17:01:57.88 |
+39:09:16.4 |
HIP 83186 |
22.04 |
| 2026-05-23 00:00 |
17:01:50.81 |
+39:09:48.5 |
HIP 83186 |
20.78 |
| 2026-05-23 12:00 |
17:01:43.72 |
+39:10:19.8 |
HIP 83186 |
19.54 |
| 2026-05-24 00:00 |
17:01:36.61 |
+39:10:50.4 |
HIP 83186 |
18.32 |
| 2026-05-24 12:00 |
17:01:29.49 |
+39:11:20.1 |
HIP 83186 |
17.14 |
| 2026-05-25 00:00 |
17:01:22.34 |
+39:11:49.1 |
HIP 83186 |
15.99 |
| 2026-05-25 12:00 |
17:01:15.18 |
+39:12:17.3 |
HIP 83186 |
14.90 |
| 2026-05-26 00:00 |
17:01:08.00 |
+39:12:44.6 |
HIP 83186 |
13.86 |
| 2026-05-26 12:00 |
17:01:00.81 |
+39:13:11.2 |
HIP 83186 |
12.90 |
| 2026-05-27 00:00 |
17:00:53.60 |
+39:13:37.0 |
HIP 83186 |
12.03 |
| 2026-05-27 12:00 |
17:00:46.37 |
+39:14:02.1 |
HIP 83186 |
11.27 |
| 2026-05-28 00:00 |
17:00:39.14 |
+39:14:26.3 |
HIP 83186 |
10.65 |
| 2026-05-28 12:00 |
17:00:31.89 |
+39:14:49.7 |
HIP 83186 |
10.19 |
| 2026-05-29 00:00 |
17:00:24.62 |
+39:15:12.3 |
HIP 83186 |
9.91 |
| 2026-05-29 12:00 |
17:00:17.35 |
+39:15:34.1 |
HIP 83186 |
9.82 |
| 2026-05-30 00:00 |
17:00:10.06 |
+39:15:55.1 |
HIP 83186 |
9.94 |
| 2026-05-30 12:00 |
17:00:02.77 |
+39:16:15.4 |
HIP 83186 |
10.25 |
| 2026-05-31 00:00 |
16:59:55.46 |
+39:16:34.8 |
HIP 83186 |
10.73 |
| 2026-05-31 12:00 |
16:59:48.15 |
+39:16:53.4 |
HIP 83186 |
11.37 |
| 2026-06-01 00:00 |
16:59:40.83 |
+39:17:11.2 |
HIP 83186 |
12.14 |
| 2026-06-01 12:00 |
16:59:33.50 |
+39:17:28.2 |
HIP 83186 |
13.02 |
| 2026-06-02 00:00 |
16:59:26.17 |
+39:17:44.4 |
HIP 83186 |
13.97 |