| Parameter |
Value |
| Designation |
C/2017 E3 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-06-07T05:56:41.349120Z |
| Orbit solution date (soln_date, UTC) |
2026-06-09T11:12:24Z |
| Obs used |
632 |
| NEO |
- |
| M1 |
5.000 |
| K1 |
11.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-04-04.0000000 |
| e |
1.01272025 |
| q (au) |
5.926890 |
| a (au) |
-465.941367 |
| i (deg) |
70.710655 |
| Ω (om, deg) |
220.742407 |
| ω (w, deg) |
334.307729 |
| M (ma, deg) |
0.029472 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.638 + 3.939\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.638 |
| n |
3.939 |
| gf |
0.887 |
| gb |
-0.947 |
| k |
1.000 |
| δ90 |
6.118 |
| 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) |
| 2026-09-20 00:00 |
18:57:47.74 |
+50:26:38.0 |
HIP 93299 |
23.83 |
| 2026-09-20 12:00 |
18:57:46.80 |
+50:25:23.9 |
HIP 93299 |
24.28 |
| 2026-09-21 00:00 |
18:57:45.93 |
+50:24:09.7 |
HIP 93299 |
24.78 |
| 2026-09-21 12:00 |
18:57:45.14 |
+50:22:55.4 |
HIP 93299 |
25.33 |
| 2026-09-22 00:00 |
18:57:44.42 |
+50:21:40.9 |
HIP 93299 |
25.91 |
| 2026-09-22 12:00 |
18:57:43.78 |
+50:20:26.3 |
HIP 93299 |
26.52 |
| 2026-09-23 00:00 |
18:57:43.21 |
+50:19:11.6 |
HIP 93299 |
27.17 |
| 2026-09-23 12:00 |
18:57:42.72 |
+50:17:56.8 |
HIP 93299 |
27.86 |
| 2026-09-24 00:00 |
18:57:42.31 |
+50:16:41.9 |
HIP 93299 |
28.57 |
| 2026-09-24 12:00 |
18:57:41.97 |
+50:15:26.8 |
HIP 93299 |
29.30 |
| 2026-09-25 00:00 |
18:57:41.70 |
+50:14:11.7 |
HIP 93299 |
30.07 |
| 2026-09-25 12:00 |
18:57:41.52 |
+50:12:56.5 |
HIP 92925 |
30.06 |
| 2026-09-26 00:00 |
18:57:41.40 |
+50:11:41.2 |
HIP 92925 |
29.02 |
| 2026-09-26 12:00 |
18:57:41.36 |
+50:10:25.9 |
HIP 92925 |
28.00 |
| 2026-09-27 00:00 |
18:57:41.40 |
+50:09:10.4 |
HIP 92925 |
27.01 |
| 2026-09-27 12:00 |
18:57:41.51 |
+50:07:54.9 |
HIP 92925 |
26.05 |
| 2026-09-28 00:00 |
18:57:41.70 |
+50:06:39.4 |
HIP 92925 |
25.13 |
| 2026-09-28 12:00 |
18:57:41.96 |
+50:05:23.8 |
HIP 92925 |
24.24 |
| 2026-09-29 00:00 |
18:57:42.30 |
+50:04:08.1 |
HIP 92925 |
23.40 |
| 2026-09-29 12:00 |
18:57:42.71 |
+50:02:52.4 |
HIP 92925 |
22.60 |
| 2026-09-30 00:00 |
18:57:43.20 |
+50:01:36.7 |
HIP 92925 |
21.85 |
| 2026-09-30 12:00 |
18:57:43.76 |
+50:00:20.9 |
HIP 92925 |
21.17 |
| 2026-10-01 00:00 |
18:57:44.40 |
+49:59:05.1 |
HIP 92925 |
20.55 |
| 2026-10-01 12:00 |
18:57:45.11 |
+49:57:49.3 |
HIP 92925 |
20.00 |
| 2026-10-02 00:00 |
18:57:45.90 |
+49:56:33.5 |
HIP 92925 |
19.53 |
| 2026-10-02 12:00 |
18:57:46.76 |
+49:55:17.6 |
HIP 92925 |
19.14 |
| 2026-10-03 00:00 |
18:57:47.70 |
+49:54:01.8 |
HIP 92925 |
18.85 |
| 2026-10-03 12:00 |
18:57:48.71 |
+49:52:46.0 |
HIP 92925 |
18.64 |
| 2026-10-04 00:00 |
18:57:49.80 |
+49:51:30.1 |
HIP 92925 |
18.54 |
| 2026-10-04 12:00 |
18:57:50.96 |
+49:50:14.3 |
HIP 92925 |
18.54 |
| 2026-10-05 00:00 |
18:57:52.20 |
+49:48:58.5 |
HIP 92925 |
18.63 |
| 2026-10-05 12:00 |
18:57:53.51 |
+49:47:42.8 |
HIP 92925 |
18.82 |
| 2026-10-06 00:00 |
18:57:54.89 |
+49:46:27.1 |
HIP 92925 |
19.11 |
| 2026-10-06 12:00 |
18:57:56.35 |
+49:45:11.4 |
HIP 92925 |
19.50 |
| 2026-10-07 00:00 |
18:57:57.89 |
+49:43:55.8 |
HIP 92925 |
19.97 |
| 2026-10-07 12:00 |
18:57:59.50 |
+49:42:40.2 |
HIP 92925 |
20.52 |
| 2026-10-08 00:00 |
18:58:01.18 |
+49:41:24.7 |
HIP 92925 |
21.14 |
| 2026-10-08 12:00 |
18:58:02.94 |
+49:40:09.2 |
HIP 92925 |
21.84 |
| 2026-10-09 00:00 |
18:58:04.78 |
+49:38:53.8 |
HIP 93198 |
21.74 |
| 2026-10-09 12:00 |
18:58:06.68 |
+49:37:38.5 |
HIP 93198 |
20.47 |
| 2026-10-10 00:00 |
18:58:08.66 |
+49:36:23.3 |
HIP 93198 |
19.20 |
| 2026-10-10 12:00 |
18:58:10.72 |
+49:35:08.2 |
HIP 93198 |
17.94 |
| 2026-10-11 00:00 |
18:58:12.84 |
+49:33:53.2 |
HIP 93198 |
16.67 |