| 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) |
| 2026-03-26 00:00 |
00:03:44.72 |
+50:14:52.7 |
HIP 390 |
10.60 |
| 2026-03-26 12:00 |
00:03:51.42 |
+50:15:14.7 |
HIP 390 |
9.57 |
| 2026-03-27 00:00 |
00:03:58.13 |
+50:15:37.2 |
HIP 390 |
8.56 |
| 2026-03-27 12:00 |
00:04:04.82 |
+50:16:00.2 |
HIP 390 |
7.60 |
| 2026-03-28 00:00 |
00:04:11.51 |
+50:16:23.6 |
HIP 390 |
6.69 |
| 2026-03-28 12:00 |
00:04:18.19 |
+50:16:47.5 |
HIP 390 |
5.87 |
| 2026-03-29 00:00 |
00:04:24.86 |
+50:17:11.8 |
HIP 390 |
5.18 |
| 2026-03-29 12:00 |
00:04:31.53 |
+50:17:36.6 |
HIP 390 |
4.68 |
| 2026-03-30 00:00 |
00:04:38.18 |
+50:18:01.9 |
HIP 390 |
4.43 |
| 2026-03-30 12:00 |
00:04:44.83 |
+50:18:27.5 |
HIP 390 |
4.47 |
| 2026-03-31 00:00 |
00:04:51.47 |
+50:18:53.7 |
HIP 390 |
4.80 |
| 2026-03-31 12:00 |
00:04:58.09 |
+50:19:20.2 |
HIP 390 |
5.37 |
| 2026-04-01 00:00 |
00:05:04.71 |
+50:19:47.3 |
HIP 390 |
6.11 |
| 2026-04-01 12:00 |
00:05:11.31 |
+50:20:14.7 |
HIP 390 |
6.97 |
| 2026-04-02 00:00 |
00:05:17.91 |
+50:20:42.6 |
HIP 390 |
7.91 |
| 2026-04-02 12:00 |
00:05:24.49 |
+50:21:10.9 |
HIP 390 |
8.90 |
| 2026-04-03 00:00 |
00:05:31.06 |
+50:21:39.7 |
HIP 390 |
9.93 |
| 2026-04-03 12:00 |
00:05:37.62 |
+50:22:08.9 |
HIP 390 |
10.99 |
| 2026-04-04 00:00 |
00:05:44.16 |
+50:22:38.5 |
HIP 390 |
12.07 |
| 2026-04-04 12:00 |
00:05:50.69 |
+50:23:08.5 |
HIP 390 |
13.16 |
| 2026-04-05 00:00 |
00:05:57.21 |
+50:23:39.0 |
HIP 390 |
14.27 |
| 2026-04-05 12:00 |
00:06:03.71 |
+50:24:09.9 |
HIP 390 |
15.39 |
| 2026-04-06 00:00 |
00:06:10.20 |
+50:24:41.2 |
HIP 390 |
16.52 |
| 2026-04-06 12:00 |
00:06:16.68 |
+50:25:12.9 |
HIP 390 |
17.65 |
| 2026-04-07 00:00 |
00:06:23.13 |
+50:25:45.0 |
HIP 390 |
18.79 |
| 2026-04-07 12:00 |
00:06:29.58 |
+50:26:17.6 |
HIP 390 |
19.93 |
| 2026-04-08 00:00 |
00:06:36.00 |
+50:26:50.6 |
HIP 390 |
21.08 |
| 2026-04-08 12:00 |
00:06:42.41 |
+50:27:23.9 |
HIP 679 |
20.61 |
| 2026-04-09 00:00 |
00:06:48.81 |
+50:27:57.7 |
HIP 679 |
20.18 |
| 2026-04-09 12:00 |
00:06:55.18 |
+50:28:31.9 |
HIP 679 |
19.81 |
| 2026-04-10 00:00 |
00:07:01.54 |
+50:29:06.5 |
HIP 679 |
19.52 |
| 2026-04-10 12:00 |
00:07:07.88 |
+50:29:41.5 |
HIP 679 |
19.30 |
| 2026-04-11 00:00 |
00:07:14.20 |
+50:30:16.9 |
HIP 679 |
19.16 |
| 2026-04-11 12:00 |
00:07:20.50 |
+50:30:52.6 |
HIP 679 |
19.09 |
| 2026-04-12 00:00 |
00:07:26.78 |
+50:31:28.8 |
HIP 679 |
19.10 |
| 2026-04-12 12:00 |
00:07:33.04 |
+50:32:05.4 |
HIP 679 |
19.19 |
| 2026-04-13 00:00 |
00:07:39.28 |
+50:32:42.3 |
HIP 679 |
19.36 |
| 2026-04-13 12:00 |
00:07:45.50 |
+50:33:19.6 |
HIP 679 |
19.61 |
| 2026-04-14 00:00 |
00:07:51.69 |
+50:33:57.4 |
HIP 679 |
19.92 |
| 2026-04-14 12:00 |
00:07:57.87 |
+50:34:35.5 |
HIP 679 |
20.31 |
| 2026-04-15 00:00 |
00:08:04.02 |
+50:35:13.9 |
HIP 679 |
20.76 |
| 2026-04-15 12:00 |
00:08:10.15 |
+50:35:52.8 |
HIP 679 |
21.28 |
| 2026-04-16 00:00 |
00:08:16.26 |
+50:36:32.0 |
HIP 825 |
21.13 |