| 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) |
| 2026-07-29 00:00 |
19:05:47.12 |
+52:04:00.2 |
HIP 93875 |
27.42 |
| 2026-07-29 12:00 |
19:05:39.86 |
+52:03:33.2 |
HIP 93875 |
27.54 |
| 2026-07-30 00:00 |
19:05:32.62 |
+52:03:05.6 |
HIP 93875 |
27.71 |
| 2026-07-30 12:00 |
19:05:25.42 |
+52:02:37.2 |
HIP 93875 |
27.91 |
| 2026-07-31 00:00 |
19:05:18.26 |
+52:02:08.2 |
HIP 93875 |
28.15 |
| 2026-07-31 12:00 |
19:05:11.12 |
+52:01:38.5 |
HIP 93875 |
28.43 |
| 2026-08-01 00:00 |
19:05:04.03 |
+52:01:08.2 |
HIP 93875 |
28.75 |
| 2026-08-01 12:00 |
19:04:56.96 |
+52:00:37.1 |
HIP 93875 |
29.10 |
| 2026-08-02 00:00 |
19:04:49.94 |
+52:00:05.5 |
HIP 93466 |
29.45 |
| 2026-08-02 12:00 |
19:04:42.95 |
+51:59:33.1 |
HIP 93466 |
28.85 |
| 2026-08-03 00:00 |
19:04:36.00 |
+51:59:00.2 |
HIP 93530 |
28.08 |
| 2026-08-03 12:00 |
19:04:29.09 |
+51:58:26.5 |
HIP 93530 |
27.04 |
| 2026-08-04 00:00 |
19:04:22.21 |
+51:57:52.3 |
HIP 93530 |
26.00 |
| 2026-08-04 12:00 |
19:04:15.38 |
+51:57:17.3 |
HIP 93530 |
24.98 |
| 2026-08-05 00:00 |
19:04:08.59 |
+51:56:41.8 |
HIP 93530 |
23.96 |
| 2026-08-05 12:00 |
19:04:01.83 |
+51:56:05.6 |
HIP 93530 |
22.96 |
| 2026-08-06 00:00 |
19:03:55.12 |
+51:55:28.7 |
HIP 93530 |
21.97 |
| 2026-08-06 12:00 |
19:03:48.45 |
+51:54:51.3 |
HIP 93530 |
21.00 |
| 2026-08-07 00:00 |
19:03:41.83 |
+51:54:13.2 |
HIP 93530 |
20.04 |
| 2026-08-07 12:00 |
19:03:35.25 |
+51:53:34.4 |
HIP 93530 |
19.10 |
| 2026-08-08 00:00 |
19:03:28.71 |
+51:52:55.1 |
HIP 93530 |
18.19 |
| 2026-08-08 12:00 |
19:03:22.21 |
+51:52:15.1 |
HIP 93530 |
17.30 |
| 2026-08-09 00:00 |
19:03:15.77 |
+51:51:34.6 |
HIP 93530 |
16.45 |
| 2026-08-09 12:00 |
19:03:09.36 |
+51:50:53.4 |
HIP 93530 |
15.63 |
| 2026-08-10 00:00 |
19:03:03.01 |
+51:50:11.6 |
HIP 93530 |
14.85 |
| 2026-08-10 12:00 |
19:02:56.70 |
+51:49:29.2 |
HIP 93530 |
14.13 |
| 2026-08-11 00:00 |
19:02:50.44 |
+51:48:46.2 |
HIP 93530 |
13.46 |
| 2026-08-11 12:00 |
19:02:44.23 |
+51:48:02.6 |
HIP 93530 |
12.86 |
| 2026-08-12 00:00 |
19:02:38.07 |
+51:47:18.4 |
HIP 93530 |
12.34 |
| 2026-08-12 12:00 |
19:02:31.96 |
+51:46:33.7 |
HIP 93530 |
11.91 |
| 2026-08-13 00:00 |
19:02:25.90 |
+51:45:48.3 |
HIP 93530 |
11.57 |
| 2026-08-13 12:00 |
19:02:19.90 |
+51:45:02.4 |
HIP 93530 |
11.34 |
| 2026-08-14 00:00 |
19:02:13.94 |
+51:44:15.9 |
HIP 93530 |
11.23 |
| 2026-08-14 12:00 |
19:02:08.04 |
+51:43:28.8 |
HIP 93530 |
11.23 |
| 2026-08-15 00:00 |
19:02:02.19 |
+51:42:41.2 |
HIP 93530 |
11.35 |
| 2026-08-15 12:00 |
19:01:56.39 |
+51:41:53.0 |
HIP 93530 |
11.58 |
| 2026-08-16 00:00 |
19:01:50.65 |
+51:41:04.3 |
HIP 93530 |
11.92 |
| 2026-08-16 12:00 |
19:01:44.96 |
+51:40:15.0 |
HIP 93530 |
12.35 |
| 2026-08-17 00:00 |
19:01:39.33 |
+51:39:25.2 |
HIP 93530 |
12.88 |
| 2026-08-17 12:00 |
19:01:33.75 |
+51:38:34.9 |
HIP 93530 |
13.48 |
| 2026-08-18 00:00 |
19:01:28.23 |
+51:37:44.0 |
HIP 93530 |
14.15 |
| 2026-08-18 12:00 |
19:01:22.77 |
+51:36:52.6 |
HIP 93530 |
14.87 |
| 2026-08-19 00:00 |
19:01:17.37 |
+51:36:00.6 |
HIP 93530 |
15.65 |