C/2017 D5 (PANSTARRS)
| 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) |
| 2026-02-03 00:00 |
23:53:13.88 |
+50:22:30.4 |
HIP 117692 |
18.87 |
| 2026-02-03 12:00 |
23:53:18.74 |
+50:21:58.8 |
HIP 117692 |
18.90 |
| 2026-02-04 00:00 |
23:53:23.64 |
+50:21:27.7 |
HIP 117692 |
18.98 |
| 2026-02-04 12:00 |
23:53:28.59 |
+50:20:57.2 |
HIP 117692 |
19.12 |
| 2026-02-05 00:00 |
23:53:33.57 |
+50:20:27.2 |
HIP 117936 |
18.31 |
| 2026-02-05 12:00 |
23:53:38.59 |
+50:19:57.7 |
HIP 117936 |
17.39 |
| 2026-02-06 00:00 |
23:53:43.66 |
+50:19:28.7 |
HIP 117936 |
16.48 |
| 2026-02-06 12:00 |
23:53:48.76 |
+50:19:00.3 |
HIP 117936 |
15.56 |
| 2026-02-07 00:00 |
23:53:53.91 |
+50:18:32.4 |
HIP 117936 |
14.64 |
| 2026-02-07 12:00 |
23:53:59.09 |
+50:18:05.1 |
HIP 117936 |
13.72 |
| 2026-02-08 00:00 |
23:54:04.31 |
+50:17:38.2 |
HIP 117936 |
12.80 |
| 2026-02-08 12:00 |
23:54:09.56 |
+50:17:12.0 |
HIP 117936 |
11.88 |
| 2026-02-09 00:00 |
23:54:14.86 |
+50:16:46.2 |
HIP 117936 |
10.97 |
| 2026-02-09 12:00 |
23:54:20.19 |
+50:16:21.0 |
HIP 117936 |
10.05 |
| 2026-02-10 00:00 |
23:54:25.56 |
+50:15:56.4 |
HIP 117936 |
9.14 |
| 2026-02-10 12:00 |
23:54:30.96 |
+50:15:32.2 |
HIP 117936 |
8.23 |
| 2026-02-11 00:00 |
23:54:36.40 |
+50:15:08.7 |
HIP 117936 |
7.32 |
| 2026-02-11 12:00 |
23:54:41.88 |
+50:14:45.6 |
HIP 117936 |
6.42 |
| 2026-02-12 00:00 |
23:54:47.39 |
+50:14:23.1 |
HIP 117936 |
5.54 |
| 2026-02-12 12:00 |
23:54:52.93 |
+50:14:01.2 |
HIP 117936 |
4.68 |
| 2026-02-13 00:00 |
23:54:58.51 |
+50:13:39.8 |
HIP 117936 |
3.86 |
| 2026-02-13 12:00 |
23:55:04.12 |
+50:13:19.0 |
HIP 117936 |
3.11 |
| 2026-02-14 00:00 |
23:55:09.77 |
+50:12:58.7 |
HIP 117936 |
2.50 |
| 2026-02-14 12:00 |
23:55:15.44 |
+50:12:38.9 |
HIP 117936 |
2.16 |
| 2026-02-15 00:00 |
23:55:21.15 |
+50:12:19.7 |
HIP 117936 |
2.21 |
| 2026-02-15 12:00 |
23:55:26.89 |
+50:12:01.0 |
HIP 117936 |
2.63 |
| 2026-02-16 00:00 |
23:55:32.66 |
+50:11:42.9 |
HIP 117936 |
3.29 |
| 2026-02-16 12:00 |
23:55:38.46 |
+50:11:25.4 |
HIP 117936 |
4.07 |
| 2026-02-17 00:00 |
23:55:44.29 |
+50:11:08.4 |
HIP 117936 |
4.92 |
| 2026-02-17 12:00 |
23:55:50.15 |
+50:10:51.9 |
HIP 117936 |
5.80 |
| 2026-02-18 00:00 |
23:55:56.04 |
+50:10:36.0 |
HIP 117936 |
6.71 |
| 2026-02-18 12:00 |
23:56:01.96 |
+50:10:20.6 |
HIP 117936 |
7.64 |
| 2026-02-19 00:00 |
23:56:07.91 |
+50:10:05.8 |
HIP 117936 |
8.58 |
| 2026-02-19 12:00 |
23:56:13.88 |
+50:09:51.6 |
HIP 117936 |
9.52 |
| 2026-02-20 00:00 |
23:56:19.88 |
+50:09:37.9 |
HIP 117936 |
10.47 |
| 2026-02-20 12:00 |
23:56:25.90 |
+50:09:24.7 |
HIP 117936 |
11.43 |
| 2026-02-21 00:00 |
23:56:31.96 |
+50:09:12.1 |
HIP 117936 |
12.39 |
| 2026-02-21 12:00 |
23:56:38.03 |
+50:09:00.0 |
HIP 117936 |
13.36 |
| 2026-02-22 00:00 |
23:56:44.13 |
+50:08:48.5 |
HIP 117936 |
14.33 |
| 2026-02-22 12:00 |
23:56:50.26 |
+50:08:37.6 |
HIP 117936 |
15.31 |
| 2026-02-23 00:00 |
23:56:56.41 |
+50:08:27.1 |
HIP 117936 |
16.28 |
| 2026-02-23 12:00 |
23:57:02.58 |
+50:08:17.3 |
HIP 117936 |
17.26 |
| 2026-02-24 00:00 |
23:57:08.78 |
+50:08:08.0 |
HIP 117936 |
18.25 |