| Parameter |
Value |
| Designation |
C/2017 D5 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-01-08T20:46:08.676480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:31Z |
| Obs used |
75 |
| NEO |
- |
| M1 |
14.700 |
| K1 |
13.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-03-05.0000000 |
| e |
0.98076543 |
| q (au) |
2.167199 |
| a (au) |
112.672079 |
| i (deg) |
131.038508 |
| Ω (om, deg) |
92.721040 |
| ω (w, deg) |
287.822322 |
| M (ma, deg) |
0.045436 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.560 + 5.726\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.560 |
| n |
5.726 |
| gf |
0.996 |
| gb |
-0.998 |
| 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 |
00:12:51.38 |
+51:17:45.6 |
HIP 884 |
20.55 |
| 2026-05-12 12:00 |
00:12:55.67 |
+51:18:40.0 |
HIP 884 |
21.50 |
| 2026-05-13 00:00 |
00:12:59.92 |
+51:19:34.7 |
HIP 884 |
22.46 |
| 2026-05-13 12:00 |
00:13:04.13 |
+51:20:29.5 |
HIP 1178 |
22.42 |
| 2026-05-14 00:00 |
00:13:08.29 |
+51:21:24.5 |
HIP 1178 |
21.30 |
| 2026-05-14 12:00 |
00:13:12.41 |
+51:22:19.8 |
HIP 1178 |
20.19 |
| 2026-05-15 00:00 |
00:13:16.48 |
+51:23:15.2 |
HIP 1178 |
19.08 |
| 2026-05-15 12:00 |
00:13:20.50 |
+51:24:10.8 |
HIP 1178 |
17.98 |
| 2026-05-16 00:00 |
00:13:24.48 |
+51:25:06.6 |
HIP 1178 |
16.88 |
| 2026-05-16 12:00 |
00:13:28.41 |
+51:26:02.6 |
HIP 1178 |
15.79 |
| 2026-05-17 00:00 |
00:13:32.30 |
+51:26:58.7 |
HIP 1178 |
14.71 |
| 2026-05-17 12:00 |
00:13:36.13 |
+51:27:55.0 |
HIP 1178 |
13.63 |
| 2026-05-18 00:00 |
00:13:39.92 |
+51:28:51.5 |
HIP 1178 |
12.57 |
| 2026-05-18 12:00 |
00:13:43.66 |
+51:29:48.1 |
HIP 1178 |
11.52 |
| 2026-05-19 00:00 |
00:13:47.35 |
+51:30:44.9 |
HIP 1178 |
10.48 |
| 2026-05-19 12:00 |
00:13:50.99 |
+51:31:41.9 |
HIP 1178 |
9.47 |
| 2026-05-20 00:00 |
00:13:54.59 |
+51:32:39.0 |
HIP 1178 |
8.48 |
| 2026-05-20 12:00 |
00:13:58.13 |
+51:33:36.2 |
HIP 1178 |
7.54 |
| 2026-05-21 00:00 |
00:14:01.62 |
+51:34:33.6 |
HIP 1178 |
6.65 |
| 2026-05-21 12:00 |
00:14:05.06 |
+51:35:31.1 |
HIP 1178 |
5.84 |
| 2026-05-22 00:00 |
00:14:08.45 |
+51:36:28.8 |
HIP 1178 |
5.15 |
| 2026-05-22 12:00 |
00:14:11.79 |
+51:37:26.6 |
HIP 1178 |
4.62 |
| 2026-05-23 00:00 |
00:14:15.08 |
+51:38:24.5 |
HIP 1178 |
4.32 |
| 2026-05-23 12:00 |
00:14:18.32 |
+51:39:22.5 |
HIP 1178 |
4.29 |
| 2026-05-24 00:00 |
00:14:21.51 |
+51:40:20.7 |
HIP 1178 |
4.54 |
| 2026-05-24 12:00 |
00:14:24.64 |
+51:41:18.9 |
HIP 1178 |
5.03 |
| 2026-05-25 00:00 |
00:14:27.72 |
+51:42:17.3 |
HIP 1178 |
5.69 |
| 2026-05-25 12:00 |
00:14:30.75 |
+51:43:15.8 |
HIP 1178 |
6.46 |
| 2026-05-26 00:00 |
00:14:33.73 |
+51:44:14.4 |
HIP 1178 |
7.32 |
| 2026-05-26 12:00 |
00:14:36.65 |
+51:45:13.1 |
HIP 1178 |
8.24 |
| 2026-05-27 00:00 |
00:14:39.52 |
+51:46:11.8 |
HIP 1178 |
9.19 |
| 2026-05-27 12:00 |
00:14:42.33 |
+51:47:10.7 |
HIP 1178 |
10.17 |
| 2026-05-28 00:00 |
00:14:45.10 |
+51:48:09.7 |
HIP 1178 |
11.16 |
| 2026-05-28 12:00 |
00:14:47.80 |
+51:49:08.7 |
HIP 1178 |
12.17 |
| 2026-05-29 00:00 |
00:14:50.46 |
+51:50:07.9 |
HIP 1178 |
13.19 |
| 2026-05-29 12:00 |
00:14:53.06 |
+51:51:07.1 |
HIP 1244 |
12.47 |
| 2026-05-30 00:00 |
00:14:55.60 |
+51:52:06.4 |
HIP 1244 |
11.41 |
| 2026-05-30 12:00 |
00:14:58.09 |
+51:53:05.8 |
HIP 1244 |
10.36 |
| 2026-05-31 00:00 |
00:15:00.52 |
+51:54:05.2 |
HIP 1244 |
9.31 |
| 2026-05-31 12:00 |
00:15:02.90 |
+51:55:04.7 |
HIP 1244 |
8.27 |
| 2026-06-01 00:00 |
00:15:05.22 |
+51:56:04.2 |
HIP 1244 |
7.24 |
| 2026-06-01 12:00 |
00:15:07.49 |
+51:57:03.8 |
HIP 1244 |
6.22 |
| 2026-06-02 00:00 |
00:15:09.70 |
+51:58:03.5 |
HIP 1244 |
5.22 |