| Parameter |
Value |
| Designation |
P/2017 G2 (PANSTARRS) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2017-06-13T21:56:20.866560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:32Z |
| Obs used |
165 |
| NEO |
- |
| M1 |
12.900 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-05-16.0000000 |
| e |
0.65031280 |
| q (au) |
2.846253 |
| a (au) |
8.139426 |
| i (deg) |
47.906245 |
| Ω (om, deg) |
79.819627 |
| ω (w, deg) |
105.939134 |
| M (ma, deg) |
358.772777 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.648 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.648 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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) |
| 2026-06-01 00:00 |
01:39:23.25 |
-40:58:27.5 |
HIP 7760 |
16.87 |
| 2026-06-01 12:00 |
01:39:32.79 |
-40:59:02.3 |
HIP 7827 |
16.19 |
| 2026-06-02 00:00 |
01:39:42.28 |
-40:59:38.0 |
HIP 7827 |
14.41 |
| 2026-06-02 12:00 |
01:39:51.72 |
-41:00:14.4 |
HIP 7827 |
12.65 |
| 2026-06-03 00:00 |
01:40:01.09 |
-41:00:51.6 |
HIP 7827 |
10.94 |
| 2026-06-03 12:00 |
01:40:10.42 |
-41:01:29.6 |
HIP 7827 |
9.28 |
| 2026-06-04 00:00 |
01:40:19.68 |
-41:02:08.4 |
HIP 7827 |
7.72 |
| 2026-06-04 12:00 |
01:40:28.89 |
-41:02:48.0 |
HIP 7827 |
6.31 |
| 2026-06-05 00:00 |
01:40:38.04 |
-41:03:28.4 |
HIP 7827 |
5.18 |
| 2026-06-05 12:00 |
01:40:47.14 |
-41:04:09.5 |
HIP 7827 |
4.54 |
| 2026-06-06 00:00 |
01:40:56.17 |
-41:04:51.4 |
HIP 7827 |
4.58 |
| 2026-06-06 12:00 |
01:41:05.14 |
-41:05:34.1 |
HIP 7827 |
5.29 |
| 2026-06-07 00:00 |
01:41:14.06 |
-41:06:17.6 |
HIP 7827 |
6.44 |
| 2026-06-07 12:00 |
01:41:22.92 |
-41:07:01.8 |
HIP 7940 |
7.54 |
| 2026-06-08 00:00 |
01:41:31.71 |
-41:07:46.8 |
HIP 7940 |
5.92 |
| 2026-06-08 12:00 |
01:41:40.44 |
-41:08:32.6 |
HIP 7940 |
4.48 |
| 2026-06-09 00:00 |
01:41:49.11 |
-41:09:19.2 |
HIP 7940 |
3.43 |
| 2026-06-09 12:00 |
01:41:57.72 |
-41:10:06.5 |
HIP 7940 |
3.18 |
| 2026-06-10 00:00 |
01:42:06.27 |
-41:10:54.6 |
HIP 7940 |
3.88 |
| 2026-06-10 12:00 |
01:42:14.75 |
-41:11:43.4 |
HIP 7940 |
5.15 |
| 2026-06-11 00:00 |
01:42:23.17 |
-41:12:33.0 |
HIP 7940 |
6.67 |
| 2026-06-11 12:00 |
01:42:31.53 |
-41:13:23.4 |
HIP 7940 |
8.29 |
| 2026-06-12 00:00 |
01:42:39.82 |
-41:14:14.5 |
HIP 7940 |
9.97 |
| 2026-06-12 12:00 |
01:42:48.04 |
-41:15:06.4 |
HIP 7940 |
11.68 |
| 2026-06-13 00:00 |
01:42:56.20 |
-41:15:59.0 |
HIP 7940 |
13.40 |
| 2026-06-13 12:00 |
01:43:04.29 |
-41:16:52.4 |
HIP 7940 |
15.14 |
| 2026-06-14 00:00 |
01:43:12.31 |
-41:17:46.5 |
HIP 7940 |
16.87 |
| 2026-06-14 12:00 |
01:43:20.26 |
-41:18:41.3 |
HIP 7940 |
18.61 |
| 2026-06-15 00:00 |
01:43:28.15 |
-41:19:36.9 |
HIP 7940 |
20.34 |
| 2026-06-15 12:00 |
01:43:35.97 |
-41:20:33.2 |
HIP 7996 |
20.82 |
| 2026-06-16 00:00 |
01:43:43.72 |
-41:21:30.2 |
HIP 7996 |
20.75 |
| 2026-06-16 12:00 |
01:43:51.39 |
-41:22:28.0 |
HIP 7996 |
20.81 |
| 2026-06-17 00:00 |
01:43:59.00 |
-41:23:26.5 |
HIP 7996 |
20.99 |
| 2026-06-17 12:00 |
01:44:06.54 |
-41:24:25.7 |
HIP 7996 |
21.29 |
| 2026-06-18 00:00 |
01:44:14.00 |
-41:25:25.6 |
HIP 7996 |
21.71 |
| 2026-06-18 12:00 |
01:44:21.40 |
-41:26:26.2 |
HIP 7996 |
22.23 |
| 2026-06-19 00:00 |
01:44:28.72 |
-41:27:27.6 |
HIP 7996 |
22.85 |
| 2026-06-19 12:00 |
01:44:35.96 |
-41:28:29.6 |
HIP 7996 |
23.56 |
| 2026-06-20 00:00 |
01:44:43.14 |
-41:29:32.3 |
HIP 7996 |
24.36 |
| 2026-06-20 12:00 |
01:44:50.24 |
-41:30:35.7 |
HIP 7996 |
25.22 |
| 2026-06-21 00:00 |
01:44:57.26 |
-41:31:39.8 |
HIP 7996 |
26.15 |
| 2026-06-21 12:00 |
01:45:04.21 |
-41:32:44.6 |
HIP 7996 |
27.13 |
| 2026-06-22 00:00 |
01:45:11.09 |
-41:33:50.1 |
HIP 8320 |
26.25 |